Unionville Serpentine Barrens Restoration and Management Plan

Roger Latham

and Mike McGeehin

Cover: The highest‐priority targets for restoration and management at the Unionville Barrens are serpentine Indian‐grass – little bluestem grassland (top), serpentine gravel forb community (right center) and serpentine seep (bottom). They are globally rare communities and harbor an extraordinary diversity of species of special conservation concern. (Photos by Roger Latham.)

Suggested citation for this document:

Latham, R. E. and M. McGeehin. 2012. Unionville Serpentine Barrens Restoration and Management Plan. Continental Conservation, Rose Valley, Pennsylvania and Natural Lands Trust, Media, Pennsylvania. 157 pp. + 10 maps.

Unionville Serpentine Barrens Restoration and Management Plan

Roger Latham Continental Conservation Rose Valley, Pennsylvania

and Mike McGeehin Natural Lands Trust

For Natural Lands Trust Media, Pennsylvania

2012

Table of Contents

Summary ...... 1 1 Introduction ...... 3 1.1 Background on serpentine barrens ...... 3 1.2 Importance of grassland conservation ...... 9 1.3 Significance of the Unionville Barrens ...... 11 1.4 Purpose of the restoration and management plan ...... 13 2 Project Area Description ...... 15 2.1 Physiographic and geological setting ...... 15 2.2 Land‐use history ...... 16 2.3 Ecosystem components ...... 20 2.3.1 Historical vegetation ...... 20 2.3.2 Soils ...... 23 2.3.3 Present‐day ecological communities ...... 29 2.3.4 Species surveys ...... 33 2.3.4 Vascular plant species of special conservation concern ...... 37 2.3.5 Animal species of special conservation concern and their habitat needs ...... 38 3 Desired Conditions, Indicators of Management Success, and Threats ...... 41 3.1 Desired conditions ...... 41 3.1.1 Qualitative summary of desired conditions ...... 41 3.1.2 Species diversity and composition ...... 42 3.1.3 Structural, patch and habitat diversity ...... 43 3.1.4 Ecosystem processes ...... 45 3.1.5 Landscape context ...... 48 3.1.6 Metrics of ecosystem condition—the phytometer approach ...... 49 3.2 Threats ...... 61 3.2.1 Critically low population numbers associated with habitat area decline ...... 61 3.2.2 Fire exclusion and forest succession ...... 62 3.2.3 Invasive and aggressive plant species ...... 63 3.2.4 Artificially elevated white‐tailed deer population ...... 64 4 Management Recommendations ...... 67 4.1 Adaptive management ...... 67 4.1.1 Selective tree removal and replacement ...... 68 4.1.2 Prescribed burning ...... 71 4.1.3 Invasive and aggressive species control ...... 73 4.1.4 Deer management ...... 78 4.1.5 Species reintroduction and augmentation ...... 79 4.1.6 Maintaining esthetic and historical preservation standards ...... 79 4.2 Monitoring ...... 80 4.2.1 Quadrat monitoring of vascular plant species cover ...... 80 4.2.2 Monitoring sparsely distributed plant species of special conservation concern ...... 82 4.2.3 GIS metrics ...... 82 4.2.4 Monitoring bird populations ...... 82 4.2.5 Monitoring arthropod populations ...... 82 4.2.6 Monitoring deer effects ...... 83 ii

4.2.7 Baseline surveys focusing on ecosystem components of special conservation concern ...... 83 4.3 Stewardship task priorities and timeframe ...... 84 4.3.1 Management units ...... 84 4.3.2 Highest‐priority stewardship tasks for 2012–2013 ...... 90 References Cited ...... 92 Acknowledgments ...... 100 Glossary ...... 101

Appendices Appendix A. Interpretation of rank and status codes for species of special conservation concern ...... 109 Appendix B. Vascular plants of the Unionville Barrens ...... 111 Appendix C. Arthropods of special conservation concern that may inhabit the Unionville Barrens ...... 145 Appendix D. Notes on design of adaptive management trials ...... 149 D.1 Replication ...... 149 D.2 Randomization ...... 150 D.3 Experimental control ...... 151 D.4 Standards of evidence ...... 152 Appendix E. Online information sources for major invasive species in the Unionville Barrens ...... 154

Site Maps Map 1. Landscape context ...... 159 Map 2. Serpentine grasslands, 1937 ...... 161 Map 3. Serpentine grasslands, 1971 ...... 163 Map 4. Vegetation structure, 2008 ...... 165 Map 5. Grassland succession history, 1937–2010 ...... 167 Map 6. Estimated soil depth to bedrock ...... 169 Map 7. Estimated soil A‐horizon thickness ...... 171 Map 8. Features of special conservation concern or historical significance ...... 173 Map 9. Existing and potential trails, vehicular access and firebreaks ...... 175 Map 10. Serpentine barrens restoration and management units ...... 177

Tables Table 1. Plants documented at the Unionville Barrens before 1912 but not found in recent (2002–2011) surveys ...... 22 Table 2. Comparison of soil chemistry between soils derived from serpentinite and those derived from other bedrock types ...... 25 Table 3. Summary of the vascular plant flora of the Unionville Barrens and adjacent forest ...... 34

iii

Table 4. Summary of the characteristic serpentine grassland species present at the Unionville Barrens ...... 35 Table 5. Plants of special conservation concern recorded recently at the Unionville Barrens ...... 35 Table 6. Plants of special conservation concern documented historically but not seen recently at the Unionville Barrens ...... 37 Table 7. Desired conditions, metrics, target values and existing conditions of the Unionville Barrens ...... 50 Table 8. Sizes of management units and their component grassland and forest management areas ...... 85 Table 9. Prioritization of major recommendations for restoration and management of the Unionville Barrens ...... 86 Table 10. Summary of highest‐priority stewardship tasks for 2012–2013 ...... 91 Table A‐1. Explanation of global and state rarity ranks ...... 109 Table A‐2. Explanation of Pennsylvania Biological Survey (PABS) status codes ...... 110 Table A‐3. Explanation of Pennsylvania conservation tier codes ...... 110 Table B‐1. List of the vascular plants of the Unionville Barrens ...... 112 Index to Table B‐1 ...... 132 Table C‐1. Arthropods of special conservation concern that may inhabit Unionville Barrens ...... 146

Figures Figure 1. Ultramafic bedrock and estimated peak historical extent of serpentine barrens in the Northern Piedmont ...... 5 Figure 2. Decline in serpentine grassland area at Unionville Barrens, 1937–2010, due to forest succession ...... 23 Figure 3. Comparison of soil A‐horizon thickness across succession history categories ...... 28 Figure 4. Comparison of soil A‐horizon thickness between wooded (forest and woodland) and open (grassland) areas ...... 28 Figure 5. Autumn‐olive removal plots ...... 75

Summary

In value for biodiversity conservation, The plan’s underpinnings include two the Unionville Barrens rank among the studies undertaken as part of the planning highest‐priority sites in southeastern effort: (1) creation and analysis of a Pennsylvania. A globally rare ecosystem chronosequence of vegetation maps and a cluster of rare species give the site showing changes between 1937, 1958, national or even global significance. The 1971, 1990 and 2010 using air and satellite ecosystem—temperate eastern North imagery and digital mapping (GIS) tools; American serpentine barrens—consists of a (2) systematic sampling and mapping of species‐rich set of ecological communities soil physical characteristics. The GIS associated with soils weathered from analysis documents the history of grassland serpentinite bedrock, a rare geological loss to forest succession, providing formation. The Unionville Barrens feature signposts to the most suitable areas for traces of prehistoric and historical human grassland restoration. The soil study was land uses that also contributed in crucial based on research at another serpentine ways to the site’s unique natural qualities. barren showing soil depth to be a key factor The flora and fauna include an exception‐ in grassland persistence and rate of loss ally large number of rare, threatened and due to forest succession. That finding was endangered species. However, the barrens applied at the Unionville Barrens to explore vegetation has been losing ground for the the usefulness of simple, inexpensive soil past several decades, shrinking in area and measurements as a basis for evaluating declining in native species diversity with areas where restoration and maintenance the waning of the disturbance regime that are likely to be cost‐effective versus those formerly sustained it, in all likelihood for a where they may be prohibitively costly. timespan of several thousand years. This Specific, measurable objectives for plan offers an outline of how the decline of desired conditions were developed based this treasured piece of our natural heritage on what is known about the ecology and can be reversed and key processes restored history of the Unionville Barrens and other to insure the long‐term sustainability of the native grasslands and serpentine barrens in serpentine barrens ecosystem and its the region. In the plan, desired conditions component species. are itemized and compared with existing Grasslands make up a small fraction of conditions to serve as the basis for the total serpentine barrens area but they strategies to narrow the gap between the harbor nearly all of the rare species. Other two. Methods to achieve the desired serpentine barrens communities conditions are outlined. Specific areas of intermixed with and surrounding the land are prioritized for such tasks as patches of grassland include unusual invasive species eradication, selective tree woodland and wetland communities. The removal, creation of standing dead snags, total serpentine grassland area at the soil organic matter removal, seedbank Unionville Barrens has declined drastically augmentation, propagation and planting of from more than 63 acres in 1937, the selected species, restoration burning and earliest credible size estimate, to 7 acres in maintenance burning. 2010. It is crucial to the conservation of the The plan takes an adaptive management entire set of serpentine barrens approach, which, in brief, consists of communities to restore as much as is carrying out a set of actions, periodically feasible of the area of grassland recently monitoring the results, reconsidering the lost to forest succession.

methods in light of those results, and Monitoring is in essence an audit—a adjusting the next round of implementation systematic, disciplined approach to accordingly. This approach is a way of evaluate and improve the effectiveness of reducing uncertainty without high‐cost management. The plan outlines a strategy research. Trials of promising alternative for monitoring a set of indicators to track methods for achieving objectives are changes in conditions resulting from both carried out and results compared quan‐ management actions and external causes titatively as a part of routine management. and to improve consistency, rigor and Monitoring is an indispensible part of efficiency in measuring progress toward adaptive management, generating practical achieving and sustaining the desired new knowledge that is promptly put to use. conditions.

Introduction

1.1 Background on serpentine barrens The open grasslands, Barrens cover a small fraction of the greenbrier thickets and oak total bedrock area. Grasslands, in turn, 1woodlands at the Unionville make up a small fraction of the barrens, Barrens are collectively which are mainly woodland and forest with called serpentine barrens: barrens because a canopy of blackjack oak, post oak and farmers long ago discovered that the soils sometimes pitch pine, usually intermixed were poor for growing crops, and with other oak species, eastern red‐cedar serpentine because the main cause of the and Virginia pine. Serpentinite bedrock infertility—the bedrock from which the underlies approximately 15,500 acres in soils are weathered—is a rare rock Pennsylvania1, 23,400 acres in Maryland2, formation called serpentinite. Serpentine and 400 acres in Delaware3, a total of grassland is one of the rarest natural 39,300 acres or 86 square miles (Figure 1). communities in eastern North America. In contrast, the total area of serpentine Grasslands, pine‐oak and oak woodlands, barrens vegetation totals approximately and the other ecological communities that 1,800 acres in Pennsylvania and 1,600 make up serpentine barrens live on thin acres in Maryland4; serpentine barrens soils overtop a geologic oddity, a vegetation has been extirpated from metamorphic, light‐green rock formed in Delaware. The sum of the remaining area of deep cracks on the seafloor. Most of the all Northern Piedmont serpentine barrens earth’s supply of serpentinite still lies is an estimated 3,400 acres or just over 5 buried under the seafloor, far beneath the square miles, covering less than 9% of the surface of the world’s oceans. It is rare on area underlain by serpentinite bedrock the continents, present in North America, (Figure 1). for example, only in a few scattered, The serpentinite underlying the barrens isolated patches from Georgia to and nearby forest and farmland (see Maps Newfoundland and in Alaska, Oregon, 1, 2 and 3) formed beneath the Iapetus California, Costa Rica and Cuba. Ocean, a predecessor to the Atlantic, most The Unionville Barrens are an example likely around a half‐billion years ago. of a globally rare complex of related Serpentinite is a metamorphic rock, formed ecological communities known as by slow chemical changes to the igneous temperate eastern North American rock peridotite, the main constituent of the serpentine barrens. Never very abundant, earth’s crust beneath the bottoms of the this ecosystem has declined through world’s oceans. Serpentinization occurs attrition from nearly 40 sites when where peridotite is exposed to seawater. botanists began keeping records to less Olivine and pyroxenes—the main mineral than 20 sites today (Figure 1, p. 5). Around constituents of peridotite—are converted 93% of the total area remaining is on the into serpentine minerals by the Northern Piedmont of Pennsylvania incorporation of water into their crystalline (~ 49%), Maryland (~ 44%) and New York (very small remnants on Staten Island). The 1 Pennsylvania Bureau of Geologic and Topographic rest is on the Piedmont in northeastern Survey (2001) Georgia (~ 6%) and on the Blue Ridge in 2 Cleaves et al. (1968) western North Carolina (~ 1%). 3 Plank et al. (2000) 4 R. E. Latham, unpublished data 3

structures. Serpentine minerals have the fragments of ocean‐bottom rock that had general chemical formula Mg3Si2O3(OH4). jumbled together with the continental Serpentinite by definition is rock rich in rocks at the suture line lay deep inside the serpentine minerals, but it has other mountains. North America and Africa chemical attributes that set it apart from parted once again and at least 100 million most other types of rock, including higher years of erosion by runoff and landslides iron, nickel, cobalt and chromium and have slowly worn the mountains down, lower calcium. Igneous peridotite and its depositing most of their bulk as silt and metamorphic offspring, including rubble on the continental shelf off the serpentinite, are classified as ultramafic Atlantic coastline and the bottom of the rocks, reflecting their very high magnesium Western Interior Seaway, a shallow sea that (“ma”) and iron (“f” for ferric) contents1. As covered the middle of North America. The a side note, serpentinization is gaining igneous and metamorphic rocks at the recognition as of vital importance for the surface of the present‐day Northern original emergence of life on earth, and Piedmont, including small, scattered areas possibly on other planets, because the of serpentinite (Figure 1), were deep inside hydrogen released during the process was a the core of that long‐gone mountain range. key energy source for metabolism and with The soil that forms overtop serpentinite geothermal heating it combined with CO to 2 bedrock is different from any other soil in form organic compounds vital to cell the world. Its key characteristics from the formation, including hydrocarbons and plants’ perspective are unusually high fatty acids2. levels of magnesium (Mg) and nickel (Ni) This begs the question, how did rock and very low calcium (Ca) content. Because that formed beneath the bottom of the the plant life of serpentine barrens is ocean end up at the surface of a continent? stunted, the soil is often assumed to be The answer involves plate tectonics. During overly well drained and sandy like the an extremely slow but almost inconceivably coastal plain soils of the New Jersey Pine colossal collision of North America with Barrens. This is a misconception. Africa that swept up a volcanic island arc Serpentine soil is actually a moist loam. similar to today’s Japanese archipelago, the Where it is not extremely thin or eroded, its last remnant of the Iapetus Ocean was texture and moisture content are squeezed out of existence between 350 and comparable to those of a good agricultural 300 million years ago. Most of the sea‐ soil3. It is the soil’s peculiar chemical bottom rock was overridden by the drifting characteristics that make it a challenging continents and pressed downward into the medium for plant growth. Most plants need earth’s molten interior, but a few broken much more Ca than serpentine soil can pieces caught on the continent’s edge and provide. At the same time Mg, an essential stuck there. Like cars crashing in slow mineral for plant growth, is present in such motion, the two continents’ crumpled high concentrations that it can be toxic, a leading edges compressed horizontally and textbook case of “too much of a good thing.” rose vertically, forming a Himalaya‐sized In parts of some serpentine barrens, Ni also mountain range, much as the Himalayas are may be abundant enough to deter the still forming today while greater India, once growth of many plant species. a huge island, continues its ongoing slow The unusual soil mineral conditions, in collision with the rest of Asia. The few particular high Mg and Ni and low Ca, are collectively known as the “serpentine soil 1 Discussion of serpentinite mineralogy is based on Brooks (1987) 2 Müntener (2010) 3 Hull and Wood (1984); Latham (1993)

Figure 1. Ultramafic bedrock (green) and estimated peak historical extent of serpentine barrens (square symbols) in the Northern Piedmont (light brown). Serpentine vegetation is documented historically at 32 sites on the map (15 still exist) as covering a small fraction of the total area underlain by ultramafic bedrock (serpentinite). Sources: bedrock geology—Pearre and Heyl (1960); barrens locations and estimated peak historical acreages—R. E. Latham (unpublished data). Base map shows Level III ecoregions adjoining the Northern Piedmont (National Health and Environmental Effects Research Laboratory 2011)—Ridge and Valley (yellow); Blue Ridge (purple); Southeastern Plains (buff), Middle Atlantic Coastal Plain (light blue); Atlantic Coastal Pine Barrens (light green). syndrome”1. Several studies have shown been shown to reduce the toxic effects of that Ca is the limiting factor for plant both Mg and Ni6. 2 growth in serpentine soils , and other The serpentine soil syndrome is most research points to high Mg or Ni levels as pronounced where soils are eroded and the primary constraints3. These findings shallow. Only a small fraction of the are complementary rather than regional flora thrives under such contradictory. High Mg levels are toxic only conditions. By slowing plant growth, the in the absence of sufficient levels of serpentine soil syndrome promotes low mitigating Ca4 and many serpentine species macronutrient (nitrogen, phosphorus and have high calcium‐use efficiency5. Ca has potassium) turnover rates, hampering growth of macronutrient‐demanding

1 Jenny (1980) species, including most invasive nonnative 2 E.g., Proctor and Woodell (1971) species, even if they are tolerant of the 3 Nagy and Proctor (1997) 4 Proctor (1970) 6 E.g., Gabrielli and Pandolfini (1984); Proctor and 5 Kruckeberg (1984) McGowan (1976) 5

serpentine soil syndrome1. The resulting costly in energy and resources that such sparse vegetation casts little shade, plants are incapable of the rapid height resulting in high soil surface temperatures, growth needed to compete successfully which in turn intensify drought stress. This with common plants on ordinary soil. They combination of factors is a powerful grow faster and larger on more fertile soil, deterrent to many plants and results in but not as fast or as large as ordinary plants high levels of endemism as well as high that lack the ability to endure on serpentine local fidelity of many non‐endemic species soil. This tradeoff is the key to why the to serpentine soils2. Serpentine barrens can serpentine barrens flora is very different also provide important refugia for native from any other ecological community in the flora and fauna not formerly limited to region. The characteristic plants of the serpentine habitats but presently serpentine barrens are poor competitors in outcompeted by invasive species elsewhere forests and other commonplace habitats in their range. surrounding the barrens. Likewise, the The thinner the soil over serpentinite plants that are good competitors on bedrock, the more pronounced the effects ordinary soil lack the ability to thrive on are of low Ca and high Mg and Ni. Where serpentine soil. the soil is thinnest at the Unionville Even though the serpentine barrens Barrens, the plants that grow best are plants are unusually tolerant of the harsh small, highly stress‐tolerant grasses, conditions, the soil chemistry and erosion‐ graminoids and forbs, including many of maintained shallowness alone are not the rare, threatened and endangered enough keep their competitors at bay in the species living at the site. The typical cover long term. They depend on periodic on slightly thicker soils consists of disturbance to prevent the buildup of perennial, warm‐season prairie grasses organic matter and gradual development of such as little bluestem, Indian‐grass and more favorable soil conditions, which lead side‐oats grama mixed with a variety of to replacement by common forest other grasses, sedges, rushes and vegetation. For tens of millions of years wildflowers, including the rest of the (with interruptions during the past two Unionville Barrens’ rare, threatened or million years by more than a dozen ice endangered species. Serpentine grasslands ages), such disturbance for the most part are often called serpentine savannas probably resulted from foraging, trampling, because stunted trees, including post oak, bedding down and wallowing by large, blackjack oak and eastern red‐cedar, grow plant‐eating animals. In what is now sparsely among the grasses. Pennsylvania and the mid‐Atlantic region, Relatively few species of plants are woolly mammoth, Columbian mammoth, equipped to deal with the unusual American mastodon, Wheatley’s ground 3 shaped chemistry of serpentine soil. Even the sloth and Jefferson’s ground sloth ecosystems by toppling trees, scarifying characteristic plants of serpentine barrens and compacting the soil, and starting a have stunted growth on serpentine soil, but cascade of indirect effects4, resulting in a unlike ordinary plants, they can “tough it patchwork of persistent grasslands within a out.” Still, they pay a price for this ability. matrix of forest. Herds of mid‐sized The anatomical and biochemical inner herbivores would have kept some of the workings that enable some plants to tolerate extreme soil conditions are so 3 Guilday (1971); Kurtén and Anderson (1980); Williams et al. (1985); Russell Graham, personal communication (2007) 1 Huenneke, et al. (1990) 4 Milchunas et al. (1988); Folke et al. (2005); Zimov et al. 2 Kruckeberg (1984) (1995)

areas disturbed by the giant herbivores pasture usually has a residue of nutrients open and in grass cover, just as they do in added in fertilizer or manure, which fosters Africa today where the presence of the rapid establishment and growth of elephants is associated with the persistence seedlings. In early succession, plants of of grasslands even where there is enough different growth forms, whether they are rain to support forests1. In what is now trees, shrubs, grasses or other herbs, are all southeastern Pennsylvania those mid‐sized small in stature. In mid‐succession, trees grazers and browsers were eastern elk, and shrubs have grown taller than their moose, white‐tailed deer and a host of now‐ herbaceous neighbors. Still later, the trees extinct species, among them the black bear‐ outstrip the shrubs in height and the sized giant beaver, giant horse, complex‐ community becomes a young woodland or toothed horse, Cope’s tapir, vero tapir, long‐ forest. When some of the trees have nosed peccary, Leidy’s peccary, flat‐headed reached full maturity, a forest has entered peccary, fugitive deer and stag‐moose2. The late succession. Any often‐observed extinctions of the last native elephants and sequence of this type is called a giant ground sloths and most of the mid‐ successional pathway or trajectory. sized grazers and browsers occurred nearly The unusual soil chemistry together simultaneously with a wave of human with crowding by the dense grasses make it immigration or cultural change around hard for most of the tree species native to 13,000 years ago, 1,000–2,000 years or our region to germinate and survive in more after humans first arrived in the area. serpentine grassland. But in the absence of Ironically, people began opening up disturbance, a transformation occurs along grasslands in eastern North America the margins of the patches where grass thousands of years ago by setting fires, meets forest. Each year, full‐grown forest inadvertently restoring some of the habitat trees in our region deposit 10 to 20 tons or diversity that had declined when nearly all more of dead leaves per acre3. The leaves of the megaherbivores died out, a decompose and enrich the soil’s upper catastrophe that most likely had been layers in organic matter. These layers are caused, directly or indirectly, by them or rich in nutrients and available moisture and their ancestors. forest plant species concentrate most of The dependence of grasslands in their root growth there. Organic matter‐ eastern North America on disturbance— rich soils also form beneath overhanging first by megaherbivores, later by fire, and trees along the grassland edge, making the still later by livestock grazing and mining— soil there suitable for colonization by trees, involves the process ecologists call shrubs and invasive plants, including succession. Succession refers to the gradual species sensitive to the unusual chemistry replacement of one kind of ecological of serpentine soil4. Furthermore, the partial community by another on the same piece of shade at the forest edge suppresses the land. The most familiar example of native grassland plants, which are succession in eastern North America is intolerant of shade, while favoring the what happens when a farm field is growth of tree seedlings and other forest abandoned. There is a constant rain species, which are intolerant of the extreme everywhere of seeds of many plant species, summer heat in the middle of a patch of including trees. Abandoned cropland or grassland. Disturbances that kill adult trees, remove tree seedlings, or consume or remove dead leaves and other organic 1 Dublin et al. (1990) 2 Guilday (1971); Kurtén and Anderson (1980); Williams et al. (1985); Russell Graham, personal communication 3 José‐Luis Machado, personal communication (2005) (2007) 4 Barton and Wallenstein (1997) 7

matter inhibit soil buildup. Only with Despite what most of us were taught in regular disturbance do grasslands such as history class, not all the Mid‐Atlantic region those at the Unionville Barrens persist in was forested when Europeans first arrived. spite of succession. Evidence is still accumulating from pollen The Unionville Barrens’ exceptional core analysis and other research to confirm diversity of grassland‐specialist plants and what is implied in the earliest historical the large number of rare species are good writings—grasslands and meadows were indicators that grassland has existed there far more widespread in prehistoric eastern for a very long time. We have no direct North America than has been generally evidence farther back than the earliest appreciated. Even before Native Americans botanical records in the 1800s, but high were largely displaced, nearly all of the grassland diversity and the cluster of rare grasslands and meadows succeeded into species are solid clues that the grassland’s forests or were converted into plowed age is at least on the order of a thousand fields. Only where the soils were too poor years. Its origin may well date back to the to grow crops or to support rapid invasion most recent major episode of global by forest trees (for instance, the thin soil warming, which occurred between 8,000 over serpentinite bedrock) were native and 4,500 years ago. With warming came grasslands sustained after the local demise frequent drought—each drought was a of Indian cultural practices. Even most of setback for succession, with young trees those places were covered over by forest dying for lack of water—together with vegetation eventually. Only the few acres more widespread and frequent fires. But that were kept cleared by livestock grazing, the climate turned cooler and wetter wildfires or activity associated with mining around 4,500 years ago and stayed that still have native grassland vegetation today. way until the mid‐twentieth century, The grasslands that persisted the longest reducing the incidence of lightning‐ignited were those where plant growth is slowest wildfires to what it has been during due to unfavorable soil or microclimate, recorded history in the region, which is because there it took fewer and less near zero. Some Native American cultural frequent disturbances to keep the normal groups regularly burned their woods and process of forest establishment at bay. fields and many ecologists accept that it Native grasslands in the northeastern was this practice that made it possible for United States stir esthetic and scientific the barrens to persist until European interest because they are rare and beautiful settlement. Indians who used fire to modify landscapes and habitats for unusual the landscape in eastern North America did clusters of rare species. But part of their it most likely to improve game habitat, value and appeal is also cultural, historic encourage the growth of certain fire‐ and anthropological. Despite their wild enhanced sources of food such as appearance they are relics of an ancient blueberries, huckleberries, blackberries way of life, a part of our cultural heritage. and raspberries, and extend visibility, Any formerly Indian‐maintained grasslands which would have made it easier to hunt, that still persist in the northeastern United travel and maintain “homeland security.” States have been preserved and There is no direct evidence—no maintained, however inadvertently, by “smoking flint”—of Native American Westerners ever since they replaced Native burning at the Unionville Barrens, but Americans as stewards of the land. It is only several lines of circumstantial evidence recently that conservation agencies and point to a strong likelihood that the private groups like Natural Lands Trust grassland is, in essence, an Indian artifact. have made the long‐term stewardship of such places intentional.

1.2 Importance of grassland conservation Scientists conducting a global study of highest quality food and habitat for native conservation needs recently tallied the total grassland animal species. The typical areas of habitat converted or destroyed and grassland or meadow today is an of habitat protected in all of the major abandoned field invaded by a few ecosystem categories worldwide1. The introduced species—multiflora rose, picture is upbeat for certain ecosystems— autumn‐olive, Japanese honeysuckle, Amur including tundra, boreal forest and taiga, honeysuckle, Canada thistle, mile‐a‐minute montane grassland and shrubland, and and stiltgrass are examples—that crowd temperate conifer forest—but it is bleak for out the native plants and degrade the many others. Of all ecosystem types habitat for most native animal species. evaluated, temperate grassland, the Native grasslands are now rare indeed. category that includes the open area at the Simply protecting native grasslands in Unionville Barrens, is in the direst straits. rainy eastern North America is not enough For temperate grassland (including to sustain them. Where it is left unimpeded savanna) and shrubland together, the ratio the processes of soil development and of acres destroyed to acres protected is ten forest succession transform the unique to one, five times higher than even the native grassland communities, with their beleaguered tropical rainforest. Worldwide, high species diversity and many rare only 5% of the land in temperate grassland species, to common forests of moderate to and shrubland has been protected to date very low native species diversity and while 46% has already been destroyed. The abundant introduced invasive species. figures are even more dismal for the Invasive nonnative plants that are common eastern United States, where native in the woods near the edges of the grasslands have been under extreme Unionville Barrens grasslands include pressure for more than 300 years and most autumn‐olive, Oriental bittersweet, were converted long ago to agricultural, Japanese honeysuckle, Amur honeysuckle, residential, commercial and other uses. multiflora rose and stiltgrass. Some native Historically, grasslands occurred as species also can take advantage of the soil‐ breaks in the eastern deciduous forest building and heat‐shielding opportunities resulting from disturbances such as fire, of the forest‐grassland edge and begin periodic flooding, insect infestation and overrunning the grassland, including red clearing by humans—first by American maple and greenbrier. Black locust, Indians and later by settlers from the Old introduced from farther west in North World. Most grasslands and meadows in America, invades the grassland in a eastern North America are short‐lived different way—established trees in the ecosystems. Without repeated disturbance, surrounding woods send in underground trees and other forest plants seed in rapidly runners, new stems shoot up from those and reestablish the forest. runners in what would ordinarily be hostile Since the first European settlement, territory, and the mother trees subsidize native grasslands have steadily declined. shoots’ water and nutrient needs through These ecological communities were once the runners until they build up enough soil home to hundreds of native plant species organic matter from shed, nitrogen‐rich that, for millions of years, provided the leaves to support healthy root systems of their own. The result of invasion by native and nonnative plants is the shrinkage and 1 Hoekstra et al. (2004) 9

disappearance of the grassland ecosystem invasive. Insects are the richest source of and all of its characteristic species. The fats and protein for birds and for many eventual result would be the tragic and small animals that, in turn, are food for irreversible loss of an extraordinary larger animals. The result is that far less of ecosystem that has existed for thousands of the total plant biomass is converted, via the years. food chains that make up the food web, into Most grasslands or meadows in animal biomass where nonnative plants are southeastern Pennsylvania have a recent abundant. The higher the cover and species agricultural past—old hayfields or richness of native plants in a patch of pasture—and are dominated by nonnative grassland or meadow, the higher the insect cool‐season grasses planted for centuries as biomass will be, which, in turn, enables fodder, such as tall fescue, perennial native wildlife species to reach and sustain ryegrass, Kentucky bluegrass, orchard grass full abundance and diversity. and timothy. Grasslands and meadows of Ancient native grassland remnants such native warm‐season grasses, native cool‐ as those at the Unionville Barrens have season grasses and native forbs are now incalculable value as scientific, historical rare but they provide far better habitat for and esthetic resources, as reference sites many species of native wildlife, especially for grassland restoration and reclamation, birds, than do old fields dominated by and as the last stands of many locally and nonnative plants, which have become much regionally indigenous genotypes1. Native more common. Native grasses, both warm‐ grasslands share two key distinctions with season and cool‐season, are mainly wetlands: they are crucial for biodiversity bunchgrasses, unlike the sod‐forming conservation out of proportion to their growth habit of most nonnative hay, small total area and they declined severely pasture and lawn grasses. Grasses growing during the twentieth century. Recognition in tufts with space in between provide high‐ of their importance lags behind that of quality nesting sites and allow grassland wetlands, but is making steady gains. birds and other animals to move more Pennsylvania’s Wildlife Action Plan2 easily and with better protection from identifies grasslands as a high priority for predators in their search for food. The protection and stewardship. space between clumps also provides room Estimated from historical records, for native forbs. grasslands and meadows within the area of More importantly, native grasslands present‐day Pennsylvania covered 230–240 and meadows are more valuable to wildlife square miles around the time of European than old fields with mostly nonnative plants contact, just over 0.5% of the state’s land because they are also far better habitats for area3. To put that figure into perspective, the local arthropod fauna, mainly insects. the estimated present‐day wetland cover is Insects are vital links in many of the food 380 square miles or 0.8%4. Surviving chains that make up the food web in remnants of early grasslands, including ecosystems. Most insect species are those at the Unionville Barrens, now sum to specialist feeders on just one native plant less than 1 square mile (0.002% of the species or a narrow range of species. The state’s area)— a 99.6% decline, which close associations between the insect and plant species native to our region 1 developed over millions of years. Invasive Latham and Thorne (2007) 2 Pennsylvania Game Commission and Pennsylvania Fish nonnative plants seldom are utilized as a and Boat Commission (2005) food resource by native insect species, 3 Historical and present‐day native grassland and meadow which is one of the reasons why they are acreage estimates are from Latham (2005). 4 Myers et al. (2000)

continues and is even accelerating at many early successional grasslands, which sites. Open areas dominated by nonnative typically exist for less than a decade), is species, often with extremely low species roughly 0.01% of the state’s land area2. diversity and little value as wildlife habitat, These small areas harbor a vastly cover a much larger area in the state than disproportionate number of species of grasslands and meadows dominated by conservation concern. Of Pennsylvania’s diverse mixtures of native plants. A recent endangered plants, 112 (38%) typically estimate based on satellite imagery places inhabit persistent grasslands and 19.5% of Pennsylvania’s land in grassland meadows, as do 35 (41%) of those cover and other cover types with similar classified as threatened, and 38 (35%) of signatures in satellite images such as the plants that have been extirpated from 1. The pasture and recently cut forest the state since European settlement. At amount of land in grasslands dominated by least 94 (51%) of the butterfly and moth native species is unknown, but likely species classified as endangered, accounts for well under 1% of the state’s threatened or rare in the state are known land area. The area in long‐persistent to depend in part or wholly on grasslands grasslands, including serpentine and meadows3. grasslands (in contrast with short‐lived,

1.3 Significance of the Unionville Barrens The Unionville Barrens have been affirmed yet again in 2010 when the recommended three times for National barrens, protected in part by Natural Lands Natural Landmark status4, a testament to Trust the previous year, were designated their special value, which has been by the Pennsylvania Department of recognized by botanists since at least as far Conservation and Natural Resources as a back as the early 1800s5. Two members of Wild Plant Sanctuary. Unionville’s Seal family contributed The exceptional diversity of native plant botanical specimens from the Unionville species at the Unionville Barrens includes Barrens to the herbarium of the Academy of populations of at least 18 plant species of Natural Sciences of Philadelphia from the special conservation concern in 1850s through the 1890s. Francis Whittier Pennsylvania, including one globally Pennell, curator of botany at the Academy threatened species (detailed later). This is a of Natural Sciences of Philadelphia and the phenomenally large cluster of imperiled foremost twentieth‐century botanical species for a natural community that is now authority on Pennsylvania’s serpentine seven acres in size, although less than 70 barrens, first visited the site in 1908. The years ago the serpentine grassland at barrens have been a mecca for botanists Unionville was almost ten times larger. and ecologists for well over a century in Another nine plant species of special spite of restricted access by private concern have been recorded from the landowners. The value of the site was Unionville Barrens but not seen in recent years. Their disappearance is in all 1 The sum of “woody transitional (5% < cover of woody plant foliage < 40%), also shrubland or forest regeneration” and “perennial herbaceous 3 Species tallies are from Latham (2005a) (grasslands, pasture, forage, old fields < 5% 4 Radford and Martin (1975); Erdman (1977); shrubs)” (Myers et al. 2000) Latham (1984) 2 Latham (2005a) 5 Darlington (1826, 1837)

likelihood a consequence of the dire loss in are where the most rapid evolution is area of grassland habitat due to forest taking place. Any mutation that happens to succession with the interruption of the increase survival or reproduction under disturbance regime (see Figure 2, p. 23). local conditions can quickly spread It is next to certain that animal species throughout a small, isolated population. If classified as endangered, threatened or rare they have been isolated for long enough are also present. However, to date no one and far enough from their species’ main has done a systematic animal survey at the range, some disjunct and peripheral Unionville Barrens. There are nearly 50 populations when studied intensively are animal species of special concern known so determined to be new varieties or far at the State Line Barrens, a series of subspecies or even new species. This serpentine grasslands and woods along the likelihood is higher the more specialized Mason‐Dixon Line in Pennsylvania and the habitat is; grassland underlain by Maryland. Scientists expect to find many serpentine soils is a prime example. more kinds of rare animals on serpentine The Unionville Barrens rank high in barrens eventually. So far, even at the State conservation importance among the few Line Barrens relatively little effort has been serpentine barrens that still exist. Part of put into wildlife surveys except to search the reason is that site quality, species and for butterflies and moths. Searches have habitat diversity, and potential long‐term been made of the Unionville Barrens viability are high relative to the other specifically targeting three rare insect remaining serpentine barrens in the region. species, two plant bugs that feed on Landscape context also makes the creeping phlox and one beetle whose larvae Unionville Barrens uniquely important. feed on the native grasses little bluestem Temperate eastern North American and big bluestem1. The rare plant bugs serpentine barrens occur in four widely were not found at Unionville but the rare separated areas—the core area in beetle, which lives mainly in the prairies of Pennsylvania and Maryland (and formerly the Midwest and West, was found there in Delaware), with 14 extant sites, and three 1987 (see Appendix C, p. 148). outliers in Georgia, North Carolina and New Except for serpentine aster, the only York, consisting of one large, one small and serpentine barrens endemic living in the two or three very small sites, respectively. barrens, the species of special conservation The core area, in turn, is divided into three concern are—or were in the case of discrete clusters (Figure 1, p. 5), which extirpated species—at the edges of their coincide with the former mining districts main ranges or disjunct (separated) from associated with serpentinite bedrock, them. Most live mainly in the drier identified in the mining literature as the Midwest, or in the hotter South, or on the Baltimore (southwestern), State Line sandy Atlantic Coastal Plain. The ranges of a (central) and West Chester (northeastern) 2. Each of the clusters has a few of the special‐concern plants even districts distinctive flora. The Unionville Barrens extend into the Southwestern deserts and are, and probably always were, the largest parts of Mexico. Disjunct and peripheral single area of serpentine vegetation and populations are of special conservation historically harbored the largest diversity concern in part because their members of serpentine barrens‐restricted plant usually are genetically distinct from species in the West Chester cluster. Its individuals of the same species living location at the southwestern end of the elsewhere. In many cases these populations cluster nearest to the larger State Line

1 Wheeler (1988, 1995) 2 Pearre and Heyl (1960)

Barrens complex potentially makes it a metapopulation are interconnected by critical steppingstone for species that occasional cross‐migration. Individuals can occasionally find their way from one recolonize a site where a species has died serpentine barrens “island” to another. out locally. Gene flow among habitat islands For thousands of years, when a wild is maintained, lessening the deleterious population was extirpated from one of the effects of inbreeding. Now that only 6 are local group of serpentine barrens, the left of the serpentine grasslands that once species had a chance of regaining its lost numbered 21 in the West Chester cluster, foothold by chance recolonization from one spontaneous “rescue” of extirpated species of the other sites in the group. Ecologists or replenishment of a diminished gene pool term this the rescue effect. Species of is much less likely. “Assisted migration” as serpentine grassland‐restricted animals part of an ecosystem restoration program and plants have always been distributed may be the only way to mitigate such among the “archipelago” of serpentine losses. As the largest and most species‐rich barrens as metapopulations—groups of of those remaining sites, the Unionville partially isolated populations belonging to Barrens’ role as a regional source and safe the same species. The subpopulations of a haven for imperiled species populations is more crucial than ever.

1.4 Purpose of the restoration and management plan The primary purpose of this plan is to A secondary purpose of the plan is to provide guidance to Natural Lands Trust serve as an educational and fundraising (NLT) for the restoration and management tool. Detailed background on the natural of the serpentine barrens ecosystem at the history, scientific significance and Unionville Barrens. The overarching goal is conservation importance of this ancient to restore and maintain a suite of habitats remnant of our natural heritage—and of that sustains the long‐term integrity of the native grasslands in general—is presented serpentine barrens ecosystem, including in a non‐technical way, in recognition of the the imperiled species of flora and fauna and value of imparting this information to a a diversity of serpentine barrens broader audience beyond NLT conservation communities. and stewardship staff.

Project Area Description

2.1 Physiographic and geological setting The Unionville Barrens lie in The nearest serpentinite outcrops of the Piedmont Uplands (Level greater size are 9 miles southeast in 2 IV ecoregion) of the Northern Christiana Township, New Castle County, Piedmont (Level III), within Delaware and 9 miles northeast, where a the Eastern Temperate Forests (Level I)1. long, narrow band crosses East Goshen, Rounded hills, low ridges and narrow Willistown and Eastttown Townships in valleys characterize the Piedmont Uplands, eastern Chester County (see Figure 1, p. 5). which extend from the falls on the The nearest extant serpentine barrens are Delaware River near Trenton, New Jersey on smaller outcrops: Marshallton Barrens, to a point about 40 miles southwest of 3½ miles northeast (less than 1 acre in size; Charlottesville, Virginia, reaching a width of part of NLT’s Stroud Preserve); Brintons about 40 miles between the Susquehanna Quarry, 6 miles east (about 2 acres; owned and Potomac Rivers. The local section is the and managed by the Quarry Swimming 330 square‐mile watershed of Brandywine Association); and Fern Hill, 7 miles Creek, whose West Branch passes within northeast (approximately 30 acres; mostly 3,000 feet northeast of the barrens. owned by a developer and proposed to be Elevations typically range from 200–1,000 turned over to a homeowners association2). feet above mean sea level, with relatively Historically, there were two more sharp local relief of 130–330 feet1. serpentine barrens within that distance Elevations in the Unionville Barrens and range but they no longer exist; they were at immediate surroundings range from 300 Sconnelltown and Strodes Mill, about 4½ feet just downstream along Corundum Run and 5 miles east‐northeast (areas to nearly 470 feet where Cannery Road unknown)3. crosses the top of Corundum Hill (labeled The West Chester cluster of serpentine on Map 8). barrens, which formerly numbered at least The Piedmont Uplands are underlain by 21 sites, extended from the Unionville metamorphic rocks, principally schist, Barrens and Mt. Cuba Barrens, the gneiss and quartzite, with small areas of extirpated site in Delaware, at the cluster’s serpentinite and marble and narrow dikes western and southern ends to a site (now of the igneous rocks diabase and pegmatite. also extirpated) 18 miles away at the The barrens occupy nearly half of the cluster’s northeastern corner. The nearest largest serpentinite outcrop in central site within the State Line Barrens—the Chester County, an area of approximately largest serpentine barrens cluster in 260 acres in Newlin Township (Map 1). temperate eastern North America in terms Two pegmatite dikes running north‐south of acreage—lies 16 miles southwest of the split the serpentinite bedrock area and the Unionville Barrens (Figure 1). barrens. One is close to and roughly Culturally, the area surrounding the parallels the courses of Feldspar Run and Unionville Barrens is a rural but lower Corundum Run and the other is suburbanizing landscape, a mosaic of aligned with Serpentine Run along the cultivated fields—mainly used to grow hay, barrens’ east side (Maps 2, 3 and 4).

2 Conestoga‐Rovers & Associates (2010) 1 Wood et al. (1999) 3 Pennell (1910; 1912) 15

corn and soybeans—alternating with small townships and the Pennsylvania to medium‐size blocks of forest. Other Agricultural Conservation Easement surrounding land uses and cover types Purchase Program have protected one‐ include orchards, pastures, reclaimed third of the area within the 6 mile‐wide native grasslands and single‐family square centered on the barrens (nearly residences. Land protection efforts have 30,000 acres) by acquiring fee interest and been intensive and highly successful. NLT, easements (Map 1). Most of the protected Brandywine Conservancy, Chester County, land is forested or actively farmed.

2.2 Land‐use history Nothing is known of the prehistory of of Shenks Ferry society1. Nothing is known the Unionville Barrens before European of the burning practices of the Shenks Ferry settlement except a reasonable inference— people or of any of their predecessors living from the existence of a highly diverse in the region. The nearest place where assemblage of rare grassland‐dependent there is a well‐documented timeline of the plants in a mostly forested landscape—that incidence of fire is southeastern New York the site was regularly included in State, where landscape‐scale burning first presumably much larger areas subjected to spiked around 9,000 years ago and was repeated burning by American Indians. The variable but persistent until falling steeply practice of burning to create and maintain at the time of European settlement2. landscapes favorable for game habitat, Pehr Lindeström, an engineer in 1654– travel, security and production of useful 1656 for the New Sweden colony in plants likely waxed and waned locally many present‐day southeastern Pennsylvania, times through the millennia as people of Delaware and southwestern New Jersey, different cultural traditions came and went. was an eyewitness to local burning Archaeologists can confidently date only practices by the native Lenape. In his the most recent events in the chronology of memoir, he wrote an account, later human habitation in the Brandywine Creek translated into English: watershed. Village‐dwelling Shenks Ferry Now as soon as the winter bids good night, they people, who lived mainly in the lower [the Lenape] begin with their hunts, which is Susquehanna Valley starting sometime done with a fine innovation. Now at that time of after A.D. 1000, expanded into the the year the grass which grows there, as has Brandywine Valley soon after 13501. Their been said, is as dry as hay. When now the culture collapsed throughout its territory in sachem wants to arrange his hunt, then he the early 1500s, likely because of social and commands his people [to take a position] close economic chaos resulting from mass deaths together in a circle of ½, 1 or 2 miles [the caused by European diseases transmitted Swedish mile was 36,000 feet], according to the number of people at his command. In the first indirectly from faraway European place each one roots up the grass in the settlements. The Lenape, who were position, [assigned to him] in the culturally very different from the Shenks circumference, to the width of about 3 or 4 ells Ferry people and lived mainly in seasonal [forearm lengths], so that the fire will not be camps, expanded into the Brandywine able to run back, each one then beginning to set Valley from along the Delaware River and fire to the grass, which is mightily ignited, so Atlantic coastal areas sometime after 1550, that the fire travels away, in towards the center filling the vacuum left by the disintegration of the circle, which the Indians follow with great noise, and all the animals which are found

1 Custer (1996). 2 Robinson et al. (2005)

within the circle, flee from the fire and the cries These tracts were farms from around 1730 of the Indians, traveling away, whereby the until the mid‐1800s, during which time the circle through its decreasing is more and more barrens were presumably used mainly for contracted towards the center. When now the pasture, as a source of wood and for Indians have surrounded the center with a small hunting. Any attempt to grow crops in the circle, so that they mutually cannot do each thin serpentine soils would likely have been other any harm, then they break loose with guns and bows on the animals which they then unsuccessful and short‐lived. Grazing have been blessed with, that not one can would have kept most of the invading escape and thus they get a great multitude of woody plants at bay and inadvertently all kinds of animals which are found there.1 served to protect most of the native grassland species, at least those capable of There might also have been prehistoric regenerating with repeated top‐removal exploitation of the unusual mineral (mainly grasses) and others with chemical resources of the Unionville Barrens. Some or physical defenses that make them of the serpentinite outcrops of the Northern unpalatable to most grazers. Because of the Piedmont have been identified as the soil conditions, the pasture would have locations of ancient soapstone (steatite) 2 been low in productivity relative to more quarries . Soapstone is a lustrous, highly typical grazing lands nearby. We can guess heat‐resistant, soft, easily carved rock that this situation may have led to composed mainly of the mineral talc, a overgrazing in some patches, resulting in hydrated magnesium silicate, and often erosion and removing the source of organic found with serpentinite. It has been used matter required for normal soil for thousands of years by Native Americans development and maintenance. In this way, (and others worldwide) to make figurines low‐competition refugia for serpentine and durable cookware. Any evidence of barrens‐restricted species were maintained such exploitation would in all probability over a larger area than would have been the have been eradicated by intensive mining case without grazing. in the nineteenth century, described later in this document. The ridge running through the middle of the Unionville Barrens was known as Likewise, we can only make educated Corundum Hill starting in the early guesses about the Unionville Barrens’ early nineteenth century, after the discovery of history after European settlement. Present‐ massive deposits of that mineral. day Newlin Township was first outlined in Corundum consists of aluminum oxide a survey in 1688 by the provincial crystals of nearly diamond‐like hardness. government as one large parcel, the whole Gem‐quality corundum crystals are rubies of which was purchased in 1724 by if red and sapphires if blue, purple or any Nathaniel Newlin for £800. He and his heirs other appealing color, but the output of the soon subdivided the land and resold much Unionville mines was mostly a dull gray or of it. Beginning in 1730, the area of the gray‐brown. It was crushed and used as an present‐day barrens stood in the middle of 3 industrial abrasive. At the Unionville a 548‐acre farm owned by Ellis Lewis . By Barrens, 1883 and probably well before then, the land had been subdivided to its current [c]orundum was first found in large masses lying 4 on the surface; these were a nuisance to configuration of three tracts (Map 4). farmers plowing their fields. Smaller boulders of corundum were used in stone fences. The farmers tried to drill holes in the larger masses 1 Lindeström and Johnson (1925): p. 215 for blasting, but they were too hard. They finally 2 Pearre and Heyl (1960) resorted to digging holes and burying the 3 Futhey and Cope (1881) boulders deep enough so that they would not 4 W. H. Kirk and Company (1883) 17

be struck by the plow. John and Joel Bailey where pits, spoil piles and other remnants claimed to have first recognized corundum on can still be seen. their farm sometime between 1822 and 1825.1 The other corundum mining effort of The first corundum mine at the note at the Unionville Barrens was a series Unionville Barrens was the Williams and of shafts, trenches and pits operated for 10 Platt mine (later known as the Patterson years beginning in 1879 by John W. Elliot. mine), in operation from the late 1830s The main center of activity was around the through the mid‐ to late 1860s under intersection of Cannery and Kelsall Roads, various ownerships. The raw mined including several trenches still visible in the corundum sold for up to $60 a ton woods on the northeastern side of Cannery (comparable to around $840 in 2011 Road. Pits in the grassland and woods east dollars2). Based on maps compiled by of Feldspar Run also are probably remnants mining historians3, the pit and mine waste of Elliot’s mining activities. At its peak the dumping area at the northeast end of one of main shaft of the Elliot mine was 160 feet the largest remnant grasslands (Map 8) are deep and the complex included a mill on the most likely the visible remains of the north side of Kelsall Road next to Cannery Patterson mine. Road where the corundum was crushed Businessmen George Chandler, Spencer and cemented onto grinding wheels. The Ball and Samuel Pusey bought the mines and mill were abandoned by 1895. In Patterson property in 1867 and sank a new that same decade, a Pittsburgh chemist, shaft in what they believed was promising Edward Acheson, invented an industrial ground, but they failed to find any process to make synthetic silicon carbide, corundum. With funding from another as hard as corundum but rare in nature. He investor they hired a local mineralogist, founded the Carborundum Company and John Smedley, in 1872 to explore for a new went into full‐scale production at Niagara lode elsewhere on the property. Falls, New York, which quickly made the 5 Smedley traced scattered boulders to a hilltop, mining of corundum obsolete . where he found a very large mass of corundum Another mineral mined in commercial 5 feet below the surface … The mass was quantities at the Unionville Barrens was estimated to weigh 150 tons and was exposed feldspar, a calcium sodium aluminum by trenching. This large mass of corundum silicate used in the making of high‐grade attracted much attention and was visited by ceramics including false teeth and enamel many prominent mineralogists of the day. … The corundum was very difficult to mine. It finishes for stoves. In powdered form, it could not be penetrated by drills, and the best was, and still is, used as the “no scratch” steel‐faced sledges lasted only a few hours. It abrasive in household cleansers. Johnson was broken up at fractures into boulders and Patterson’s quarries were dug into the weighing from a few pounds to a few tons. The pegmatite dike that bisects the barrens corundum was valued at $300 a ton uncrushed (Map 8). Beginning in the early 1850s its and $500 a ton crushed … 4 [roughly $5,400 and output was shipped to New York where it $9,000 in 2011 dollars]. was sold for the manufacture of porcelain Known as the Chandler‐Ball mine, the site teeth6. Large pits, some with permanent was north of Corundum Run (Map 8), standing water at the bottom, and heaps of mine waste are scattered in the woods around the upper reaches of Feldspar Run. 1 Sloto (2009): p. 98 Other quarries were dug in the pegmatite 2 S. M. Friedman, The Inflation Calculator (www.westegg.com/inflation) 5 Gigliotti (2010) 3 Pearre and Heyl (1960); Sloto (2009) 6 Specific details on the site’s mining history are from 4 Sloto (2009): p. 104 Sloto (2009).

dike along the eastern edge of the barrens erosion, and created piles of mine tailings. and operated until around the turn of the This greatly expanded the amount of twentieth century. ground where subsoil and rock was The Corundum Hill serpentine quarry exposed at or near the surface. Such produced serpentine building stone, the disturbance would have enlarged and light green‐colored stone that is familiar to stabilized areas where the plant species many residents of Chester County from most narrowly restricted in their regional scattered houses, barns, churches and distribution to serpentine barrens could public buildings dating mainly from the persist, including most of the rare species. nineteenth century, including some Such plants can persist in this region only prominent buildings on the campuses of the on thin soils where there is little University of Pennsylvania and West competition from the prevailing species of Chester University. It is apparently the surrounding forests and meadows, unknown where the stone from the which are intolerant of the serpentine soil Corundum Hill quarry was used or how syndrome. much was extracted there3. The quarry is The expansion of this highly specialized still visible in the woods near the source of habitat in the late nineteenth century in the Corundum Run as an amphitheater‐shaped aftermath of mining may have compensated depression in the hillside (Map 8). to some degree for the presumed loss of Chromite was a minor product at habitat that resulted after regular burning Unionville but the chief output of mines in stopped two centuries earlier when the the State Line and Baltimore serpentinite local Native American residents were outcrops (Figure 1, p. 5). For much of the forced out. Because the serpentine soil nineteenth century those mines were the syndrome was exceptionally severe in world’s principal source of chromium. At areas that had been disturbed by mining, that time, before the invention of stainless the serpentine grassland communities in steel and the reinvention of chrome plating those areas have been unusually stable (employed more than 2,000 years earlier in even in the absence of burning. In all likelihood, most of the 7 acres that remain China1), chromium was used mainly as a yellow pigment in paints and dyes and as a of the more than 60 acres of serpentine leather tanning agent. Reportedly about 50 grassland documented in 1937 aerial tons of chromite were extracted from the photographs has survived the scarcity of Baily mine at the Unionville Barrens. Its sustaining fire over the past 70 years only location is unknown except that it was because of the severe soil conditions somewhere on the Howell Baily farm (the brought about by mining disturbance well property now owned by the Heckert over a century ago. family), which encompasses the barrens’ Based on aerial photography beginning southeastern margin (Map 4). in 1937 (Maps 2, 3 and 4) we can infer that Without a doubt, mining had a profound the barrens—after the mining era ended and long‐lasting effect on the Unionville around 1900—were used partly for pasture Barrens ecosystem. For about 60 years, but increasingly abandoned to forest mining operations and transport of succession with little or no human use, equipment and ore removed vegetation and except possibly for hunting and occasional soil in the most severely affected areas. small‐scale tree cutting. In the post‐mining Over a broader area mining‐related activity period grazing must have had much the compacted and scarified soil, promoted soil same effect as it did before mining began, slowing invasion by woody plants and the soil development that comes with it. It is 1 Cotterell (2004): p. 102 19

likely that forest succession would have grazing may have continued in parts of the chipped away at the grasslands faster barrens as late as the 1970s. Since then, through the first half of the twentieth there has been little human use of the land century without the benefit of livestock except for hunting and illicit “off‐roading” grazing. It appears on the aerial photos that by all‐terrain vehicle users.

2.3 Ecosystem components

2.3.1 Historical vegetation early twentieth centuries. Plant specimens Early 1700s to 1930s. Little is known of collected by them and others and deposited the history of the Unionville Barrens before in various herbaria are the earliest record the nineteenth century, when they began we have of the site’s flora. Pennell’s attracting the attention of botanists. It is published work on the serpentine barrens possible that the Philadelphia botanist John of Pennsylvania and Delaware listed 99 2. Bartram (1699‐1777), the first botanist of plant species at the Unionville Barrens Using that list, we can roughly reconstruct European descent born in the Americas, the Unionville Barrens flora as it was before might have been aware of the site in the the twentieth‐century drastic decline in eighteenth century but there is no direct area of the serpentine grasslands and evidence. A letter dated 6 December 1745 wetlands—communities accounting for from him to the Dutch naturalist John virtually all of the barrens’ species richness. Frederic Gronovius evidently refers to the entire extent of serpentinite outcrops and Pennell’s species list from over 100 serpentine barrens in the Northern years ago reflects a flora similar to that Piedmont: existing today in the site’s grasslands and Ye Loadstone [magnetite] lieth in a vein of a woodlands, except for 32 species that have particular kind of stone that runs near east not been found in recent (2002–2011) site and west for sixty or seventy miles or more, surveys (Table 1, pp. 22–23). It is worth appearing even with, or a little higher than evaluating those “missing” species in its surface, at three, five, eight, or ten miles pursuit of insights about what has been distance, and from ten to twenty yards lost. Not surprisingly, 11 of the 32 are broad, generally mixed with some veins of species Pennell ranked as having some cotton [asbestos]. Ye earth of each side is regional fidelity to the specialized habitat; very black, and produceth a very odd, in other words, in this part of the Northern pretty kind of Lychnis [moss phlox], with leaves as narrow and short as our Red Piedmont they occur more often than not Cedar, of humble growth, perennial, and so on serpentine barrens. Also predictably, a early as to flower, sometimes, while the high proportion (eight) are now ranked by snow is on the ground; also a very pretty the Vascular Plants Technical Committee of Alsine [barrens chickweed]. Hardly anything the Pennsylvania Biological Survey as else grows here. Our people call them species of special conservation concern in Barrens ...1 the state. Unexpectedly, 10 are species of Members of Unionville’s Seal family and wetlands including 4 serpentine barrens Francis Whittier Pennell of the Academy of specialists, one of which, forked rush, is Natural Sciences of Philadelphia were designated as endangered in Pennsylvania. among the botanists who frequented the The losses represent a substantial decline Unionville Barrens in the nineteenth and in serpentine barrens species diversity and are disproportionately species of wetlands.

1 Berkeley and Berkeley (1992): pp. 265–266 2 Pennell (1910, 1912)

1930s to the present. The earliest time grassland, low woody vegetation and tall when the extent of serpentine vegetation at woody vegetation by extracting accurate the Unionville Barrens is known with any height values from the LiDAR data and precision is 15 September 1937, the day the delineating their spatial extents. NDVI earliest available aerial photos were taken (normalized difference vegetation index) of the site. By comparing a series of aerial classification was used on 2010 multi‐ photos taken at intervals—a chronose‐ channel satellite imagery to differentiate quence—much can be learned about the between conifers (mainly eastern red‐ dynamics of the barrens vegetation. Useful cedar) and deciduous vegetation. information generated in this way includes Maps of historical and recent vegetation rates of succession from grassland to generated by the various GIS methods were woodland or forest, how succession rates overlain to discern spatial patterns in varied among landscape features, and succession from 1937 to 2010. Sampling whether there has been any disturbance‐ points were classified into six categories of caused expansion since 1937 of grassland past succession from grassland to into formerly wooded areas. woodland or forest (Map 5): The study area was defined as the • wooded since before 1937 historical extent of grassland overlying • wooded since between 1937 & 1958 serpentinite bedrock as determined from 1937, 1958, 1971 and 1992 aerial photog‐ • wooded since between 1958 & 1971 raphy, plus the mostly oak‐dominated • wooded since between 1971 & 1990 woods between the grassland patches and • wooded since between 1990 & 2010 in a narrow strip, generally less than 100 • still grassland in 2010 feet wide, along segments of the perimeter. Only the area northeast of Cannery Road None of the categories involves wooded was included; serpentine grassland also areas becoming grassland in 1937–2010 once may have existed southwest of the because only a very small acreage appeared road—most likely covering a small area, to undergo such transformation. The soil judging from 1937 aerial photos—but no heterogeneity study (to be discussed later) trace of that vegetation persists there today involved determining succession history and no practical means of estimating its from the chronosequence of vegetation historical extent has been identified. The maps for soil sampling points covering study area encompasses 95 acres (Map 4). nearly the entire site in a uniform grid with nearest neighbors separated by 65 m (213 Spatial analyses of historical and recent feet). Of the 105 sampling points, the digital vegetation were done using ESRI’s ArcGIS classification software labeled 14 as having Desktop (version 10) image classification open grassland replace tree cover at some tool and QCoherent’s LP360 LiDAR point in 1937–2010. A meticulous analysis extension for ArcGIS. Supervised image of distance to the nearest wooded polygon classification (employing on‐the‐ ground from each point showed that 10 of those fell knowledge of the vegetation occurring in close enough to the edge to be within the the study area to “train” the digital margin of error expected from such sources classification software) was performed on as lens distortion, relief displacement of the georeferenced 1937, 1958, 1971 and vertical features or parallax between flight 1992 aerial photos to delineate the spatial lines in older, non‐orthorectified aerial extent of grassland vegetation. Recent photos, or from digital classification error (2008) LiDAR (light detection and ranging in categorizing vegetation near edges, technology, using laser illumination) where there is a blending of reflectance imagery was used to distinguish among (continued on p. 23) 21

Table 1. Plants documented at the Unionville Barrens before 1912 but not found in recent (2002– 2011) surveys. Source: Pennell (1910, 1912). Species marked “S” under regional fidelity were ranked by Pennell as “much more frequent” on serpentine barrens than in other habitats in the region (none are among the 15 species he identified as “Nearly or quite restricted in Delaware and Chester Counties to [serpentine] Barrens”). Wetland status is based on Rhoads and Block (2007). Boldface type indicates species of special conservation concern (see Table 6, p. 37 for more information on them).

regional often or fidelity to always species presumed extirpated from serpentine found in Unionville Barrens in last 100 years common name(s) barrens wetlands Aletris farinosa colic‐root, white colic‐root Angelica venenosa deadly angelica, hairy angelica S Aristida longespica var. slender three‐awn, slimspike three‐awn S longespica Aureolaria pedicularia cut‐leaf false‐foxglove, fernleaf yellow false‐foxglove Carex hystericina bottlebrush sedge S W Carex scoparia broom sedge W Chamaecrista nictitans wild sensitive‐plant, sensitive partridge pea Cyperus strigosus straw‐colored flatsedge W Desmodium obtusum stiff tick‐trefoil Desmodium paniculatum panicled‐leaf tick‐trefoil Digitaria filiformis slender crabgrass Eragrostis pectinacea Carolina lovegrass, tufted lovegrass

Eupatorium perfoliatum common boneset W Juncus acuminatus sharp‐fruited rush, tapertip rush W Juncus dichotomus forked rush S W Leersia oryzoides rice cutgrass W Lespedeza capitata round‐headed bush‐clover, roundhead S lespedeza Linum virginianum slender yellow flax Malus coronaria sweet crabapple Muhlenbergia sylvatica woodland muhly, woodland dropseed W

Prenanthes serpentaria lion’s‐foot, cankerweed S Quercus prinoides × alba Faxon oak Rubus pensilvanicus Pennsylvania blackberry Salix humilis var. humilis dwarf upland willow, sage willow, prairie willow Scirpus atrovirens black bulrush, green bulrush S W

(Table continues on next page.)

regional often or fidelity to always species presumed extirpated from serpentine found in Unionville Barrens in last 100 years common name(s) barrens wetlands Scleria triglomerata whip nutrush, whip‐grass S Spiraea latifolia white meadowsweet S W Symphyotrichum ericoides white heath aster ssp. ericoides Symphyotrichum laeve var. smooth blue aster S laeve Vitis aestivalis summer grape, pigeon grape Zizia aptera golden‐alexander, meadow zizia characteristics from adjoining vegetation types. Of the remaining four points, one appears to have been cleared to expand a pasture at the barrens’ far eastern edge and the other three may represent actual disturbance events converting wooded land to open grassland, one between 1958 and 1971 and the other two between 1971 and 1990. No records were kept of wildfires or tree clearing, so there is no practical way to double‐check these findings. One of the outcomes of the succession Figure 2. Decline of serpentine grassland at history analysis was quantification of the Unionville Barrens, 1937–2010, due to rate of serpentine grassland loss to forest forest succession. Data are from supervised succession over the period 1937–2010 classification of aerial photos taken in 1937, (Figure 2, p. 23). The decline was nearly 1958, 1971 and 1990 and analysis of satellite linear at an average rate of ¾ acre per year. imagery from 2010 (see methods, p. 21). A distinct succession history pattern (Map 5) stands out in the difference between the was the main historical land‐use Kramkowski parcel (the northeastern part structuring later vegetation dynamics. of the barrens, labeled on Map 4) and the The map of succession history is a key rest of the barrens. The contrast between tool for determining the configuration and the diffuse succession on the Kramkowski size of the areas to be targeted as the parcel and the more highly localized ultimate objective for grassland restoration. succession on most of the NLT and Heckert Setting measurable objectives such as this parcels most likely reflects different is part of the desired condition analysis, the historical land‐use patterns. Based on the subject of section 3 of this document. aerial photos, the Kramkowski parcel appears to have been grazed by livestock 2.3.2 Soils more consistently and more recently than Serpentine soil data from other sites. the rest of the barrens and over nearly all of Worldwide, soils weathered from its area. Succession patterns on the NLT serpentinite characteristically have and Heckert parcels are consistent with the unusually high levels of magnesium (Mg), idea that late nineteenth‐century mining nickel (Ni), chromium (Cr) and cobalt (Co) activity, confined to relatively small areas, and low calcium (Ca) content. The amounts

and forms of Cr and Co have consistently Most of the barrens area is underlain by shown little or no affect on plant growth Chrome series soils4, derived from but high Ni concentration, low Ca‐to‐Mg serpentinite parent material and described ratio, or both have emerged as key to the taxonomically as fine, mixed, superactive, serpentine soil syndrome1. Relative to soils mesic Typic Hapludalfs5. Deconstructing in the same region weathered from other that classification6: types of bedrock, serpentine soils often are • Alfisols (the soil order) form mostly in cool also lower in the macronutrients (those to hot climates under deciduous forests and taken up in the largest amounts by are characterized by medium weathering, an plants)—nitrogen (N), phosphorus (P) and argillic horizon—a clay‐rich subsurface layer potassium (K). These features are trends; where clays have accumulated by water serpentine soil mineral concentrations vary transport from higher layers—and a from one region to another, from place to medium to high concentration of base 2+ place within a single serpentinite outcrop, cations, in this case, mainly Mg . between adjacent patches of different • Udalfs (the soil suborder) are Alfisols that vegetation type, and even within a small, have a udic moisture regime—year‐round relatively uniform patch1. high precipitation but not extremely wet. • Hapludalfs (the soil great group) are Udalfs Serpentine soils in the Northern that do not possess distinguishing features Piedmont are moist loams with texture and of other Udalfs such as a cemented horizon moisture content comparable to a good or a leached horizon. 2 agricultural soil . They tend to be rapidly • Typic Hapludalfs (the soil subgroup) are draining and drought‐prone only where Hapludalfs with characteristics intermediate very shallow. At the Nottingham Barrens in between those of 17 other variant subgroups southern Chester County, the soil depth to of Hapludalfs; those intermediate serpentinite bedrock has been found to be characteristics include an argillic horizon correlated with community type. The with an indistinct or gradual upper shallowest soils are inhabited only by boundary, relatively quick water drainage, herbaceous plants strongly associated with relatively high base saturation, and a texture serpentine barrens; the deepest soils that is loamy or clayey, not sandy. support common trees and other plant • Fine, mixed, superactive, mesic Typic species of ordinary forests typically found Hapludalfs (the soil family) further describes over other kinds of bedrock; and the soil in terms of: intermediate soil depths are typified by ° texture relative to other soils with similar mixed species assemblages3. This finding, characteristics—fine; together with the fact that serpentine ° composition of the sand, silt and clay grasslands have been steadily and rapidly components—mixed; shrinking for 70 years or more at all sites ° cation exchange activity relative to clay due to forest succession (see Figure 2, p. content—superactive; 23), suggests that soil depth over serpent‐ ° annual mean and variation of soil inite bedrock is inversely associated with temperature—mesic, which means serpentine barrens stability. Or to put it strongly fluctuating seasonally with an another way, soil depth may be a rough average over the entire year between 8°C predictor of the opposite of stability, ( 47°F) and 15°C (59°F). namely the speed of serpentine barrens loss by succession to ordinary forest.

4 Kunkle (1963) 1 Brooks (1987); Rajakaruna et al. (2009) 5 Natural Resources Conservation Service (2008) 2 Hull and Wood (1984) 6 Paraphrased from Natural Resources Conservation 3 Dubinsky (1995); R. E. Latham, unpublished data Service (1999)

Table 2. Comparison of soil chemistry between soils derived from serpentinite and those derived from other bedrock types in the Northern Piedmont. Sources of data: NCSS—National Cooperative Soil Survey (undated); Nottingham Barrens—McCandless (1998); R. E. Latham, unpublished data. “Other” parent materials are schist, gneiss, granite, sandstone and shale. NCSS data are from the uppermost mineral horizon: median thickness 9 cm (range 5–10 cm) on serpentinite, 10 cm (range 8–13 cm) on limestone, and 8.5 cm (range 5–19 cm) on other soils; samples with a plow layer (Ap horizon) were omitted from the analysis. Nottingham Barrens data are from the upper 10 cm of mineral soil.

NCSS data from counties with serpentine barrens Nottingham Barrens serpentinite limestone other serpentinite soil parent parent parent parent characteristic statistic material material materials material number of samples  4 3 14 25 median 5.9 5.0 4.4 pH (not assayed) range 4.1–6.6 4.9–5.9 3.8–6.4 median 0.55 3.7 2.0 0.24 Ca‐to‐Mg ratio range 0.20–1.1 1.1–4.6 0.25–6.5 0.064–0.61 exchangeable median 379 (not assayed) Ni (µg/g) range 0.064–0.6132.4–597

Chrome series soils tend to be mildly characteristics and ecosystem traits, to acidic, in contrast to the prevailing soils of promote the success of grassland the Northern Piedmont (see Table 2), which restoration at the Unionville Barrens by tend to be moderately to strongly acidic identifying units of land where restoration (except soils derived from calcareous is most likely to be successful and cost‐ bedrock—limestone, dolomite and marble effective. At the Nottingham Barrens open —or mafic rocks such as diabase). As in grassland was found to be associated with other serpentinite‐derived soils worldwide, the thinnest soils, forest with the thickest, Ca‐to‐Mg ratios are lower and exchangeable and greenbrier thickets and woodland with (plant‐available) Ni concentrations higher intermediate soil depths2. Research in Chrome series soils than in nearby soils conducted at the New Texas Barrens in derived from other parent materials. Lancaster County3 and decades of observation at several serpentine barrens4 Soil heterogeneity study at Unionville point to the conclusion that areas cleared of Barrens. A soil study1 was undertaken in 2010 by the authors of this document and a trees where soils are relatively thick are master’s student in environmental studies likely to support fast‐growing weedy at the University of Pennsylvania to growth and a higher abundance of invasive quantify landscape‐scale soil heterogeneity nonnatives, which can interfere with in the area where historical aerial photos reestablishment of the slower‐growing taken as early as 1937 showed serpentine serpentine grassland species. grassland cover. It is presented here in We surmised that the 50‐plus acres at abbreviated scientific paper format. the Unionville Barrens that were grassland 20–75 years ago but are now wooded could Introduction. The soil study’s goal was to apply the results of earlier research at the be classified by soil attributes along a Nottingham Barrens, which showed a restoration‐feasibility continuum. The strong association between soil 2 Dubinsky (1995); R. E. Latham, unpublished data 3 Barton and Wallenstein (1997) 1 Haegele (2011) 4 R. E. Latham, personal observation 25

thicker the soil, the faster succession is be discarded, some because they landed in likely to take place after tree removal, neighboring farm fields and others because making grassland maintenance relatively they were at least 130 m from the nearest more expensive because disturbance would GPS‐located point. have to be more frequent (prescribed At each sampling point, the thickness burning) or more intensive and severe and composition of the Oa horizon or (removal of upper soil layer). In such ground litter (dead leaves, bark and wood) situations, further interventions such as was recorded and several soil spot‐herbiciding, burning in consecutive measurements were made. A 60‐inch, ⅜‐ years and partial soil removal may be inch diameter, stress‐relieved, high‐carbon needed to keep invasives from setting seed steel soil probe was inserted to take three and to approach the desired condition in a depth‐to‐bedrock measurements roughly reasonable timeframe. In areas with one foot apart; the largest of the three thinner soil, grassland should be more measurements was considered as the best stable, requiring less frequent, less severe estimate of true soil depth. A 19‐inch long, disturbance for its upkeep and fostering a ¾‐inch diameter soil tube sampler was good grassland restoration result more used to extract a soil core and examine its rapidly, cheaply and sustainably. We profile. Depths to the bottoms of the Oi+Oe expected ranking areas in this way to be a (combined Oi and Oe horizons, roughly useful tool for cost and feasibility analysis. equivalent to the humus layer), A and B The study’s research objective was to horizons were measured and the hue measure soil depth and other easily (position on the red‐orange‐yellow‐green‐ measured physical characteristics of the blue‐purple spectrum), value (reflectivity soil (excluding any that require expensive or lightness) and chroma (color intensity) laboratory analysis) across the entire of the A, B and C horizons were determined Unionville Barrens area, and test what using a Munsell soil color chart. Dominant combination of the measurements, if any, plant species were recorded and vegetation best discriminates among several described in the area immediately categories of succession history. The test surrounding each sampling point, classified was carried out using methods of spatial into one of five vegetation types: analysis to compare the soil data with the • grassland, including savanna (< 25% tree patterns of succession history revealed in cover) the GIS study described earlier (pp. 21, 23). • oak woodland (25%–60% tree cover) Methods. A square grid of 105 sampling • oak forest (> 60% tree cover) points spaced 65 meters apart was overlain • edge (at the transition between on the map of the study area (described on grassland and forest or woodland) p. 21) using digital mapping technology • mesic forest (dominated by non‐oaks) (GIS). Grid point locations were programmed into a hand‐held global Box‐and‐whisker plots were used to positioning system unit (GPS) to enable compare the central tendency and navigation to each point in the field. Near variability of each variable across some points, despite repeated attempts on vegetation categories to determine visually different days, it was not possible to obtain which variables differ most among clear GPS satellite signals. Where such ecological communities, with particular points were within 65 m of a GPS‐located attention to variables that distinguish point, we approximated their locations grasslands from the other categories. The using a 100‐m measuring tape and a variables so selected were maximum depth sighting compass. Ten of the points had to to bedrock, Oi+Oe‐horizon thickness, A‐

horizon thickness, A‐horizon value and A‐ discriminating among succession history horizon chroma. categories (in the statistical sense of We performed discriminant function significance, using a cutoff maximum Type I analyses (DFA) to determine what combin‐ error probability of 1 in 20; see explanation ation, if any, of the measured soil variables in Appendix D under Standards of evidence, best differentiates among the six succession pp. 152–153). Also, only one variable history categories (described on p. 21). To contributes significantly to discriminating put it another way, we wished to find out among present‐day vegetation types. It is what soil physical factors are associated the same variable in both cases—thickness with fast or slow succession from grassland of the A horizon (Figures 3 and 4, opposite). to woods over the last 75 years, grassland It does equally well at distinguishing persistence, or woods established from the succession history and present‐day start. We also did DFA of the same soil vegetation because both ways of classifying variables’ ability to distinguish the six the soil sampling points have one class in present‐day vegetation categories. common, encompassing essentially the same set of points. It is present‐day We used forward stepwise DFA, in (successionally stable) grassland, which has which the software builds a model of a thicker A horizon than all the other discrimination step‐by‐step, at each step classes. The statistics associated with A‐ reviewing all variables and adding in the horizon thickness significantly one that contributes most to discrimination discriminating among categories were: between groups. It then repeats the process with the remaining variables. When it • succession history—partial Wilks’ λ = 0.88; F = 2.50; P = 0.036 (N = 95) reaches the point where adding another variable increases the model’s • present‐day vegetation—partial Wilks’ discriminating ability by less than some λ = 0.88; F = 3.14; P = 0.018 (N = 95) threshold amount, it stops, omitting that Partial Wilks’ λ (lambda) represents the variable and any others that are left. unique contribution of the variable to the We did DFA twice for each set of discriminatory power of the DFA model. It categories (succession history and present‐ can take any value between 0 and 1, with 0 day vegetation)—once with all 95 usable indicating perfect discrimination and 1, no points where we have data on maximum discrimination. The high values above total depth, A‐horizon thickness and Oi+Oe‐ indicate that the discrimination power of A‐ horizon thickness and again with the 91 horizon thickness is weak, whether applied points where we also have data on the A‐ to succession history categories or present‐ horizon Munsell color variables. day vegetation type. The soil measurements found to In the succession history analysis, the significantly discriminate among each set of DFA software included Oi+Oe‐horizon categories were then interpolated for the thickness and A‐horizon hue in the model, entire ground surface between sampling as well as A‐horizon thickness, because points using a computation‐intensive their F‐values exceed the arbitrary method called kriging. The resulting map threshold of 1, although they do not reach layers show spatial trends in those soil the threshold of statistical significance (at α characteristics across the landscape, much = 0.05, or 1 in 20). In the present‐day as the topographic map of the barrens vegetation analysis, Oa‐horizon thickness shows spatial trends in slope and aspect. ranks higher than A‐horizon thickness, and A‐horizon value and A‐horizon chroma are Results. Only one of the measured included, although only the F‐value of A‐ variables contributes significantly to horizon thickness is statistically significant.

Figure 4. Compari‐ son of soil A‐ horizon thickness between wooded (forest and woodland) and open (grassland) areas. Sampling points were classified by on‐ the‐ground observation at the time of soil sampling. See Figure 3 caption (at left) for interpretation of box‐and‐whisker plots.

Figure 3. Comparison of soil A‐horizon is: Why was total depth to bedrock strongly thickness across succession history associated with community type at the categories. “Open” refers to grassland. Nottingham Barrens but not at the Sampling points were classified by analysis Unionville Barrens? of aerial photos taken in 1937, 1958, 1971 It seems improbable that there are and 1990 and supervised classification of satellite imagery from 2010 (see methods, p. major differences in the soil‐forming or 21). Box‐and‐whisker plots show median successional processes between the two (centerline), upper and lower quartiles (box sites; they are both serpentine barrens and top and bottom) and minimum and lie only 21 miles apart. In all likelihood the maximum values (ends of “whiskers”). apparent disparity is due in large part, if not entirely, to the very different scales of Spatial trends were mapped for soil depth the two studies. In the 1995 Nottingham to bedrock (Map 6) and A‐horizon Barrens study, soil depth was measured at thickness (Map 7). 1‐m intervals along 51 transects each 10 m long, in 17 sets of three transects located Discussion. We had reason to expect that close together, each set consisting of one in total soil depth would be strongly asso‐ grassland, another in adjacent woodland ciated with present‐day vegetation type with greenbrier understory, and the third and succession history, based on the earlier in nearby forest. In the current study, the research at Nottingham Barrens. We also 95 sampling points (blue dots on Maps 6 thought it likely that other soil variables and 7) were evenly spaced across a grid at would add nuance to our understanding of 65‐m (213‐foot) intervals. the soil‐succession relationship. The Unionville Barrens study was in many ways The seeming disparity in results more sophisticated and elaborate than the highlights the importance of scale. The Nottingham Barrens study was, but— 65‐m spacing of the sampling points in our unexpectedly—it has given rise to more study makes them suited to mapping large‐ questions than answers. The main question scale trends but not small‐scale details. The

kriged (interpolated) maps of total soil added to the ChesLen Preserve in 2009), depth and A‐horizon thickness (Maps 6 and are likely to have spatially heterogeneous 7) should be interpreted with this caveat in results such as more invasive species mind. An analogy is comparing a topo‐ proliferation in some areas than in others. graphic map with 2‐foot contours (Maps 2– If the mapped soil data show an association 10 are examples) with a topographic map across the landscape between trends in soil of the same area with only 50‐foot characteristics and differences in contours; the 50‐foot contours would give restoration results, then that pattern could an idea of where the largest hills and be used to predict outcomes of later valleys are, but they would not reveal restoration work on other areas of the details made clearly visible by the 2‐foot barrens. This would give managers another contours such as localized steep slopes, flat clue, in addition to vegetation history, areas, old quarries or abandoned roadbeds. about how best to tailor management The kriged soil maps show large‐scale methods to local conditions, or at least trends but on the ground it is easy to find about what to expect in different parts of visible differences that do not conform to the landscape. The specifics will have to the local trend. For instance, some obvious wait until several years after the start of localized occurrences of very shallow soils restoration work on the NLT parcel, when and even exposed rock are in areas shown early monitoring results are in and on the total soil depth map (Map 6) as comparisons with large‐scale soil trends having generally deep soils. can be made. The results also suggest that A‐horizon 2.3.3 Present‐day ecological communities degradation may be a fast process, comparable to the rate of forest succession In the following paragraphs the and without much lag time (see Map 7). communities in the study area are named, Temperate grasslands in general are well briefly described and prioritized in one of known to have thick A horizons and four categories by conservation significance temperate forests to have thin A horizons and priority—highest, high, intermediate or none at all. Our study suggests that and low—based on global, statewide and serpentine grassland succession to forest regional rarity and degree of threat. may cause rapid change in the uppermost An ecological community (also called layer of mineral soil. It remains to be community type) is an assemblage of demonstrated how long it will take to interacting plants, animals, fungi and other reverse that process and build up a typical organisms that is fairly consistent in grassland A horizon after serpentine species composition and relative grassland restoration. It is not yet known if, abundance in similar environments or to what degree, a thicker A horizon throughout a region. Communities are affects non‐grassland species’ ability to named and grouped in hierarchical invade serpentine grasslands, either classification systems analogous to the negatively or positively. classification of species and their grouping Maps of large‐scale trends in total soil into genera, families, orders, classes, phyla, depth (Map 6) and A‐horizon thickness kingdoms and domains. But unlike most (Map 7) can serve an adaptive management species, communities are not discrete purpose. They constitute a baseline against entities. They blend into each other and which the relative success of future grass‐ where one community ends and another land restoration efforts may be compared. starts is a matter of judgment and The first restoration trials, which will take consensus among experts. Not all ecologists place only on the NLT parcel (the section believe that classifying communities produces a useful product or is even

feasible, but enough do that there is a of a few hundred square feet up to 1–2 nationwide community classification acres (yellow areas on Map 4); gravel forb project underway. It is a work in progress, community occurs as patches, mainly in the with committees in each state contributing range of 10–1,000 square feet, scattered to a system coordinated by NatureServe, an within the larger grassland matrix in areas international nonprofit conservation where soils are thinnest. organization whose mission is to provide The shorthand serpentine grassland is the scientific basis for effective used throughout this document for these conservation action1. two communities together with serpentine The classification presented here of the seep (next page). All three occur communities within the Unionville Barrens interspersed in a fine‐scale mosaic and are study area (see study area boundaries on mapped together as grassland (Map 4; also Map 4, description on p. 21) is based on see photos on cover). qualitative observation and should be Several variants of grassland exist in regarded as provisional until such time as localized areas. One is restricted to the quantitative data on the relative abundance eastern part of the Unionville barrens of species may be collected in the future. (Kramkowski parcel) and includes side‐ Brief descriptions include distribution oats grama as a co‐dominant (see Map 8). across the site, dominant and diagnostic This variant is found only at a few species, in some cases with mention of a serpentine barrens and only in the West few examples of typical subordinate Chester cluster; it is not currently species, and comments on the community’s recognized as a separate community type. dynamics over time at the site, if known. Other patches of serpentine grassland The communities are classified include arrow‐feather three‐awn as a co‐ according to Pennsylvania’s community dominant. Additional diagnostic species of classification system, a joint project of the Northern Piedmont serpentine grasslands Pennsylvania Biological Survey and include all of those listed in black (not gray) Pennsylvania Natural Heritage Program type in Table 5 (pp. 35–36). working together with NatureServe. The The serpentine gravel forb community most recent treatment in book form of the occurs where the soil is thinnest over state’s terrestrial and palustrine bedrock. Dominant species, all very short in communities was published in 19992. The stature or prostrate, include church‐mouse classification system is currently three‐awn (an annual warm‐season grass), undergoing revision for online publication serpentine aster (a globally threatened and is still in flux. The names given below serpentine barrens endemic), barrens (in boldface type) are provisional, pending chickweed, rock sandwort and moss phlox. final adoption. The aquatic communities at the barrens are classified in accordance At present all serpentine grassland at with the current (2007) aquatic community the Unionville Barrens is in the form of classification for the state3. savanna (where scattered trees or tall shrubs make up between 10% and 25% of Serpentine Indian‐grass – little bluestem the total cover) but with restoration it is grassland and serpentine gravel forb expected to become savanna interspersed community. HIGHEST CONSERVATION PRIORITY. with patches of prairie (expansive areas Scattered throughout study area in patches with less than 10% tree or tall shrub cover), as historical aerial photos show it in 1 www.natureserve.org the mid‐twentieth century. Most of the 2 Fike (1999) trees in the savanna are eastern red‐cedar, 3 Walsh et al. (2007) post oak and either blackjack oak or Bush’s

oak (a natural hybrid between blackjack and blackjack oak, but at the Unionville oak and black oak). Barrens it is still uncertain whether pure This community in all of its several blackjack oak is present. Blackjack oak or variants is globally rare, has exceptionally Bush’s oak (blackjack oak‐black oak high plant species diversity, and is the main hybrid), or possibly both, are found at the habitat for species that are regionally forest‐grassland edge. Few serpentine restricted to serpentine barrens, including barrens‐restricted species occur in this nearly all of the species of special conserva‐ community. Exceptions include post oak, tion concern inhabiting the Unionville blackjack or Bush’s oak and the shrub‐size Barrens (the subject of subsections 2.3.5 dwarf chinkapin oak. and 2.3.6, pp. 37–40). It can fairly be said to Common greenbrier is moderately to be in “critical condition” at the site, having extremely abundant. The largest area of declined by more than 88% between 1937 dense greenbrier understory lies in a long and 2010, from 63 acres (not including the strip along the northwest‐facing slope of area southwest of Cannery Road) to 7 acres. Corundum Hill, mostly within 150 feet of the remnant grasslands along the ridgetop Serpentine seep. HIGHEST CONSERVATION (on Map 9, between the grasslands and the PRIORITY. Highly localized—typically 50–500 square feet or less—scattered throughout dashed line marked potential footpath). It is matrix of serpentine grassland (and likely that greenbrier is more abundant mapped together with it in yellow areas on here than elsewhere because of an “edge Map 4), in full sun or light shade in swales effect” in which sunlight penetrates farther and spring seeps, usually on slopes. into forest edges on the north sides of openings than on other sides because of the The dominant species is tufted hair‐ angle of the sun at Northern Hemisphere grass, a native cool‐season grass (see photo mid‐latitudes. Another large greenbrier on cover). There is usually an admixture of thicket extends along both sides of plants from the surrounding grassland and Corundum Run upstream and downstream other species associated with wetlands from the Feldspar Run confluence. such as swamp thistle, slender spikerush and New York ironweed. The soil surface This community presumably differs typically does not appear wet for much of from other oak‐dominated forest types in the year. Presumably there were many having a stronger influence of the more occurrences at the Unionville Barrens serpentine soil syndrome (low Ca‐to‐Mg before most of the open grassland ratio, high Ni) because the soils are succeeded to forest and woodland. shallower. It also has generally higher soil moisture and milder soil acidity than the Oak – red maple – greenbrier serpentine others, with the probable exception of red forest. HIGH CONSERVATION PRIORITY. Mainly oak – mixed hardwood forest. on ridgetop and upper slopes of Corundum Hill (ridge labeled on Map 8) surrounding Oak – red maple – greenbrier serpentine IGH CONSERVATION PRIORITY. Like remnant serpentine grasslands. woodland. H preceding community except for lower Dominant species are several oaks density of canopy—25%–60% tree cover (including post oak, blackjack or Bush’s for woodland versus 60%–100% for oak, scarlet oak and black oak), red maple forest—and associated higher density and and common greenbrier; sassafras is also diversity of understory plants, which often frequent. Red maple co‐dominance is likely include species typically found in an artifact of fire exclusion since the mid‐ serpentine grassland. twentieth century. The diagnostic species of Mixed forb marsh. HIGH CONSERVATION this forest type range‐wide are post oak PRIORITY. Highly localized in full sun or light 31

shade on level ground in or adjacent to the this community throughout its range tends floodplains of Corundum Run and Feldspar to have cool water temperatures and high Run, in some cases adjacent to red maple – water quality and support populations of black‐gum palustrine forest. small aquatic animals that are intolerant of Diagnostic species include New York organic pollution and other alterations to ironweed, marsh fern and skunk‐cabbage. habitat and stream function. Diagnostic Other species may include slender organisms include little yellow stonefly spikerush, jewelweed, cutleaf coneflower, (genus Alloperla), tipulan crane fly (Tipula) spotted water‐hemlock, tall meadow‐rue, and dark brown spinner mayfly (Ameletus). Georgia bulrush and royal fern. The soil Species diversity is generally low. The typically appears wet for most of the year. community is considered to be rare. This community is inferred to have Red maple – black‐gum palustrine declined precipitously at the Unionville forest. INTERMEDIATE CONSERVATION PRIORITY. Barrens over the past century, based on the Highly localized within forest matrix at extirpation of 10 mostly non‐forest wetland spring seeps and on narrow floodplains of species (see Table 1, pp. 22–23). Corundum Run and Feldspar Run (most of Sparsely vegetated vernal pool. the wetlands labeled on Map 8). INTERMEDIATE CONSERVATION PRIORITY. The dominant species in the canopy, Sparsely scattered in shallow depressions shrub and herbaceous layer are most often in forest understory, including spring‐fed red maple, spicebush and skunk‐cabbage, remnants of quarries near upper reaches of respectively. Other species include black‐ Feldspar Run. gum, white ash, American sycamore, Vascular plant life is sparse or absent common winterberry, American elder, false due to the double stresses of shade and nettle and Pennsylvania bittercress. The prolonged inundation. Vernal pools are largest and most diverse swamp lies just important to amphibian populations north of Corundum Run where it crosses because they do not support most of the the four‐way trail intersection (Maps 8 and predators that eat frog and toad tadpoles 9). It has been in continuous forest cover and salamander larvae such as fish, diving since well before 1937 (compare Maps 2, 3 beetles, dragonfly larvae and crayfish. and 4). Dry oak – heath forest. INTERMEDIATE Forested headwater stream. INTERMEDIATE CONSERVATION PRIORITY. Localized near where CONSERVATION PRIORITY. Corundum Run (3,100 feet from source to ChesLen NLT‐Kramkowski parcel boundary crosses Preserve boundary), Feldspar Run (1,680 ridgetop of Corundum Hill (Map 8). feet) and segment of Serpentine Run along Dominant and diagnostic species are east end of barrens above farm pond (600 chestnut oak, mountain‐laurel, lowbush feet inside Kramkowski parcel boundary). blueberry, deerberry and black huckleberry. Scarlet, northern red, black Forested headwater streams are the uppermost reaches of perennial streams, and white oaks are also important canopy with rocky bottoms and relatively high species. This community is uncommon in gradients (5.0% for upper Corundum Run the Northern Piedmont. Although a to the confluence with Feldspar Run and comparative soil analysis has not been 2.1% from there to the preserve boundary; done, this is in all likelihood the driest and 4.8% for Feldspar Run; 3.2% for Serpentine most acidic of the oak‐dominated forest Run from the Heckert‐Kramkowski parcels’ types at the site. boundary to the pond). No aquatic surveys Dry oak – mixed hardwood forest. have been conducted on these streams but INTERMEDIATE CONSERVATION PRIORITY. Mainly

on mid‐ to upper forested slopes south and diving beetle (Agabus) and dextral pond east of Corundum Run. snail (Lymnaeidae). Species diversity is Dominant and diagnostic species are generally low. white, northern red and black oaks, pignut Tuliptree – beech – maple forest. LOW hickory, black‐gum, flowering dogwood and CONSERVATION PRIORITY. Small areas around maple‐leaf viburnum. This community is headwaters of Corundum Run, surrounded most likely intermediate in soil by successional tuliptree forest (acidic type). droughtiness and acidity among the oak‐ Tree canopy species include tuliptree, dominated forest types at the site. American beech, red maple, black cherry Red oak – mixed hardwood forest. and white ash. The occurrence is INTERMEDIATE CONSERVATION PRIORITY. Mainly depauperate, missing sugar maple and on lower forested slopes south and east of sweet birch among the community’s usual Corundum Run. dominant and diagnostic species. It is a Dominant and diagnostic species are small part of what is referred to elsewhere northern red oak, white oak, American in this document as mesic forest. beech and American hornbeam. Other Successional tuliptree forest (acidic canopy species include black cherry, red type). LOW CONSERVATION PRIORITY. Most of maple and tuliptree. The species forested area north and west of Corundum composition indicates that the community Run. has moister soils and milder soil acidity The tree canopy is overwhelmingly than the two preceding oak‐dominated dominated by tuliptree. The nonnative forest types, with little or no serpentine soil invasive shrub autumn‐olive makes up syndrome influence due to its deep, most of the understory. This community relatively organic matter‐rich soils. comprises most of what is referred to Sluggish headwater stream. LOW elsewhere in the document as mesic forest. CONSERVATION PRIORITY. 500‐foot segment of Originating in the abandonment of Serpentine Run at east end of barrens, from cultivation (compare Maps 2, 3 and 4), it is below farm pond dam to Oak School Road. marked by an even‐age canopy, low species Sluggish headwater streams are small diversity and highly disturbed soils. perennial streams with silty and rocky 2.3.4 Species surveys bottoms flowing past farm fields, pastures Only one group of organisms at the or residential areas with intermediate Unionville Barrens has been the subject of a gradients (1.0% for this stream segment). survey to date—vascular plants. The No aquatic surveys have been conducted on Brandywine Conservancy contracted a this stream but this community throughout plant survey, conducted in 2002–2003, for its range tends to have warm water what is now the ChesLen parcel within the temperatures and fair to poor water quality barrens area. Results of this survey have due to the effects of agriculture or been augmented since then by observations suburbanization on the watershed and throughout the 95‐acre barrens study area riparian area. It typically supports (summarized in Table 3, next page; full list populations of small aquatic animals that is in Appendix B, pp. 111–143). are tolerant of organic pollution, siltation and other alterations to habitat and stream Of the 356 plant species identified so function. Diagnostic organisms include far, 84 are characteristic native species of common pond snail (genus Physidae), leech Northern Piedmont serpentine grasslands (Hirudinea), ram’s‐horn snail (Planorbidae), (summarized in Table 4, p. 35). They are midge (Chironomidae), agabian predaceous marked in Appendix B according to how

tightly their distribution in southeastern growth habit of the species, but all those Pennsylvania is tied to serpentine found to date have atypical leaf grasslands. Some are nearly or quite morphology. The leaves more closely restricted, some are found more often in resemble those of black oak than the highly serpentine grasslands than in other distinctive leaves of blackjack oak seen habitats, and some are characteristic of throughout the species’ range, including serpentine grasslands but found no less just 16–30 miles away at the State Line often in other grassland habitats. The Barrens. It is possible that the entire majority, 73 species, are herbaceous, population at the Unionville Barrens is of including 25 grasses. an introgressive hybrid, that is, an Two woody species of the characteristic organism whose genome is mostly of one serpentine grassland flora are worth species (in this case, blackjack oak) but special mention—blackjack oak and Bush’s with a smaller part from another (black oak, a blackjack oak‐black oak hybrid— oak), a condition produced by repeated because of lingering uncertainty about their backcrossing of hybrid individuals with just status. Trees at the Unionville Barrens that one of the parent species. Testing this look like blackjack oak have the typical hypothesis will likely require advanced‐ branching structure, bark appearance and (continued on p. 37)

Table 3. Summary of the vascular plant flora of the Unionville Barrens and adjacent forest. See Appendix B (pp. 111–143) for sources and details on individual species. ↓ vascular plant categories ↓ species counts  native nonnative total clubmosses 2 2 nonflowering plants ferns 17 17 annual 22 18 40 forbs biennial 6 10 16

perennial 113 16 129 perennial cool‐season 13 8 21 grasses annual warm‐season 6 2 8 perennial warm‐season 12 1 13 sedges 22 22 graminoids rushes 6 6 shrubs 25 10 35 woody plants trees 31 7 38 lianas 7 2 9 total 282 74 356 major family species count major family species count Asteraceae (composites) 46 Fagaceae (oaks, beech) 14 Poaceae (grasses) 42 Polypodiaceae (ferns) 13 Cyperaceae (sedges) 22 Caryophyllaceae (pinks) 8 Rosaceae (rose family) 20 Ericaceae (ericads) 8 Fabaceae (legumes) 15 Lamiaceae (mints) 8

Table 4. Summary of the ↓ vascular plant categories ↓ species count characteristic serpentine grassland species present at the nonflowering plants ferns 1 Unionville Barrens. The species annual 5 tallied on this list are the native forbs biennial 2 vascular plants (also included in Table 3) marked S1E, S1, S2 or S3 perennial 28 in Appendix B (see explanation of perennial cool‐season 11 those symbols on p. 111). grasses annual warm‐season 5 perennial warm‐season 9 sedges 9 graminoids rushes 3 shrubs 5 woody plants trees 4 lianas 2 total 84 major family species count Poaceae (grasses) 25 Asteraceae (composites) 13 Cyperaceae (sedges) 9

Table 5. Plants of special conservation concern recorded recently at the Unionville Barrens. Sources: field inventory by J. Ebert and J. Holt (2002–2003) augmented by R. E. Latham (2003–2011) except where footnoted. Species in gray typeface do not qualify as an indigenous population (Ilex opaca) or as a population at all (a single individual of Quercus nigra), or were misidentified (Sporobolus heterolepis). global state PABS distribution (& estimated plant taxon common name(s) rank rank* status* total abundance) Ageratina aromatica small‐leaf white‐ G5 S3 PR Grasslands, edges snakeroot (> 5,000) Andropogon gyrans Elliott’s beardgrass, G5 S3 PR One small area in Elliott’s bluestem grassland (~ 10) Aristida purpurascens arrow‐feather three‐awn G5 S2 PT Grasslands (> 5,000) Bouteloua side‐oats grama, tall G5 S2 PT Grassland patches curtipendula grama near east end of barrens (> 5,000) Carex bicknellii Bicknell’s sedge G5 S1 PE One small area in grassland (~ 20) Carex richardsonii Richardson’s sedge G4 S1 PE One small area in grassland (10–100) Ceanothus New Jersey tea G5 SNR SP Grasslands americanus (50–100)

(Table continues on next page.)

* Global and state rarity ranks and Pennsylvania Biological Survey (PABS) status are explained in Appendix A, pp. 109– 110.

global state PABS distribution (& estimated plant taxon common name(s) rank rank* status* total abundance) Cerastium velutinum barrens chickweed G5T4? S3 SP Grasslands, edges var. velutinum (> 5,000) Deschampsia tufted hairgrass G5 S3 PT Moist patches in cespitosa grasslands (1,000–5,000) Dichanthelium Heller’s rosette grass, G5 S3 PT Grasslands oligosanthes Heller’s witch grass (100–1,000) Dichanthelium long‐haired panic‐grass, G5T5 SH PE Grasslands villosissimum whitehair rosette grass (100–1,000) Fimbristylis annua annual fimbry G5 S2 PT Moist patches in grasslands; present only as dormant seeds in most years (1,000–5,000) Helianthemum Bicknell’s hoary G5 S2 PE One small area in bicknellii rockrose, hoary grassland (~ 10) frostweed Ilex opaca American holly G5 S2 PT Woods; most likely escaped from cultivation and not an indigenous population (50–500) Minuartia michauxii rock sandwort, G5 SNR SP Grasslands (> 5,000) Michaux’s stitchwort Packera anonyma Small’s ragwort, G5 S2 PR Grasslands, edges Appalachian groundsel (> 5,000) Phemeranthus round‐leaf fameflower, G4 S2 PT Grasslands (50–500) teretifolius quill fameflower Quercus nigra water oak G5 † † One individual in an old collapsed mine in grassland; most likely not planted but possibly escaped from cultivation Scleria pauciflora few‐flowered nut‐rush G5 S2 PT Grasslands (> 5,000) Sporobolus prairie dropseed‡ G5 S1 PE Misidentification by heterolepis‡ several investigators, 1990–2000 Symphyotrichum serpentine aster G2 S2 PT Grasslands (> 5,000) depauperatum

* Global and state rarity ranks and Pennsylvania Biological Survey (PABS) status are explained in Appendix A, pp. 109– 110. † At present, this is the only known wild occurrence of Quercus nigra in Pennsylvania. ‡ Misidentified in 1990, 1992 and 2000 by botanists reporting to the Pennsylvania Natural Heritage Program; record corrected in 2011 with assistance from Greg Edinger, Larry Klotz and Jeff Walck.

Table 6. Plants of special conservation concern documented historically but not seen recently at the Unionville Barrens. Sources: Herbarium records compiled by the Pennsylvania Flora Project of the Morris Arboretum, University of Pennsylvania; Pennell (1910, 1912). Gray typeface: considered by the author to be a probable misidentification of a closely related plant listed in Table 5. global state PABS documentation / other plant taxon common name(s) rank* rank* status* comments Aletris farinosa colic‐root, white G5 S1 PE Collected 1884 and colic‐root 1887 by J. L. Seal, 1908 by Francis W. Pennell, 1929 by Hugh E. Stone Aristida longespica var. slender three‐awn, G5T5? S3S4 TU Reported in Pennell longespica slimspike three‐awn 1910, 1912; may have been overlooked in recent surveys Cerastium velutinum serpentine barrens G5T1 S1 PE Collected 1942 by E. var. villosissimum chickweed M. Gress; considered by author as probable misidentification of C. velutinum var. velutinum (see Table 5, pp. 35–36) Desmodium obtusum stiff tick‐trefoil G4G5 SU TU Reported in Pennell 1910, 1912 Digitaria filiformis slender crabgrass G5 S3S4 SP Reported in Pennell 1910, 1912; may have been overlooked in recent surveys Juncus dichotomus forked rush G5 S1 PE Reported in Pennell 1910, 1912 Lobelia puberula downy lobelia G5 S1 PE Collected 1935 by John M. Fogg, Jr. Prenanthes serpentaria lion’s‐foot, G5 S3 PT Collected 1908 by cankerweed Francis W. Pennell Scleria triglomerata whip‐grass, nut‐rush G5 SH PE Reported in Pennell 1910, 1912 Symphyotrichum white heath aster G5 S3 PT Reported in Pennell ericoides ssp. ericoides 1910, 1912

* Global and state rarity ranks and Pennsylvania Biological Survey (PABS) status are explained in Appendix A, pp. 109– 110. technology laboratory analysis by a Barrens should be treated as a population molecular geneticist. Introgressive hybrids of special conservation concern. have special significance in evolutionary 2.3.5 Vascular plant species of special biology because they are regarded as one of conservation concern several means by which new species can emerge. Whatever its status turns out to be, Eighteen vascular plant species of the blackjack/Bush’s oak at the Unionville special conservation concern have been 37

documented recently as living in the major animal group at the site. Relatively Unionville Barrens (Table 3, p. 34), and little effort has been put into animal another nine were documented historically surveys at any Pennsylvania serpentine at the site but have not been found in barrens except to search for butterflies and recent surveys (Table 4, p. 35). Those nine moths at a few sites. are apparently extirpated. A concept in ecology and population Serpentine aster is the only serpentine biology often invoked to help illuminate the barrens endemic living in the barrens. It is relationship between animals dependent globally rare, with less than 15 known on “island” habitats such as serpentine populations. The rest of the plants of barrens is that of sources and sinks. These special conservation concern are edge‐of‐ terms describe specific areas of contiguous range or disjunct occurrences of species habitat for a particular species across a that live mainly in the Midwest, South or region or landscape. A source is an area of Atlantic Coastal Plain, some ranging as far high‐quality contiguous habitat in which away as the desert Southwest and Mexico. the net population growth rate of the Ten of the plants of special conservation species of interest is positive. A sink is an concern have population sizes at the area of low‐quality habitat in which the net Unionville Barrens large enough to be population growth rate is negative. All of considered secure (see last column of Table the individuals of a species breeding in all 5, pp. 35–36). The rest have been squeezed of the habitats within dispersal distance of to perilously low numbers by habitat loss each other are termed a metapopulation. If over the past century. Thriving populations there were no source in a metapopulation’s of these species are the best indicators of a range, it would eventually die out. Sources healthy, functioning ecosystem. They are are essential but sinks are important, too, central to identifying desired conditions because they allow a metapopulation to be and establishing the metrics that will be larger, patchier and more genetically used to evaluate restoration and diverse than it would be if it occupied only management progress and pinpoint needs its source habitats. Larger, more dispersed for fine‐tuning management methods. and more genetically diverse populations are more resilient against setbacks and less 2.3.6 Animal species of special conserva‐ vulnerable to potential catastrophes caused tion concern and their habitat needs by unusual weather, disease outbreaks and There is no doubt that animal species other environmental variability. now classified as endangered, threatened, The best‐known animal group at rare or declining were present when the Northern Piedmont serpentine barrens in serpentine grassland area was much larger, general is the Lepidoptera. Of the hundreds and little doubt that at least a few of those of butterfly and moth species found in these species are still present, although any habitats in Pennsylvania, at least 48 of serpentine grassland habitat specialists those found so far are known to be species remaining are likely at or near critically low of special conservation concern. Three are population numbers. Only one such species globally rare—mottled duskywing and has been confirmed—in 1987 Dr. Al broad‐lined erastria moth, specialist Wheeler, Jr. discovered a population there feeders as larvae on New Jersey tea, and of the prairie leaf beetle1, which lives persius duskywing, whose larvae eat wild mainly in the Midwest and West. To date no indigo; both larval host plants are present one has done a systematic survey of any in very small populations at the Unionville Barrens. Scientists expect to find many more kinds of rare animals as more species 1 Wheeler (1988)

groups and more serpentine barrens sites Aphrodite fritillary, question mark, comma, are surveyed. mourning cloak, red admiral, painted lady, The 11 rare butterfly species and 37 American copper, black swallowtail, rare moth species so far found living in eastern tiger swallowtail and falcate orange serpentine barrens in Pennsylvania make tip. up 17% and 32% of the butterfly and moth No bird survey has yet been conducted species, respectively, listed as candidates at the Unionville Barrens. At the State Line for endangered or threatened status Barrens, some birds are consistently found statewide—fractions vastly disproportion‐ nesting in or near serpentine grasslands or ate to the relatively minuscule total area of utilizing them for other habitat needs. the serpentine barrens. Most, if not all, are Examples include prairie warbler, white‐ specialist feeders as larvae on plants that eyed vireo, eastern towhee, yellow‐ are locally abundant in some serpentine breasted chat and American woodcock. grasslands, but the larval host plants of 22 Before a recent steep decline in the regional of the 48 rare Lepidoptera that have been population2, northern bobwhite also was captured as adults in Pennsylvania commonly seen and heard. serpentine barrens are still unknown. Grassland‐obligate birds—in the Appendix C (pp. 145–148) is a Northern Piedmont including grasshopper preliminary list of arthropods of special sparrow, savannah sparrow, vesper conservation concern (pending further sparrow, eastern meadowlark, bobolink discoveries as more serpentine barrens and and horned lark—have been a focus of more arthropod groups are surveyed) conservation efforts in the region and it is considered as the most likely past, present worth mentioning why they are not or future residents of the Unionville considered likely residents of the soon‐to‐ Barrens. The list includes 10 butterflies, 32 be‐expanded grasslands at the Unionville moths, 1 beetle and 2 hemipterans or “true Barrens. The term “grassland birds” most bugs” that depend in some way on plants often refers to grassland‐obligate or presently found at the site. The list is not in grassland‐interior species. In order to nest any way exhaustive of the endangered, and successfully rear young they need threatened or rare animal species that access to large contiguous areas of treeless might inhabit the Unionville Barrens. Its grassland or meadow or to habitats that utility is in identifying several plant species supply the same nesting cues and as targets of management to enhance or resources. Pennsylvania’s breeding bird sustain habitat value for serpentine fauna includes 15 such species; two are barrens‐dependent animal life and as classified as endangered and five as additional indicators of desired conditions threatened or candidates at risk and nearly to be monitored. all have undergone serious declines in Many hundreds of more‐common recent decades due to the decline in native arthropod species occur in the barrens, grasslands and meadows. Even after including some that are declining in the restoration, the grasslands at the Unionville region and in eastern North America in Barrens may be too small and the savanna general as nonnative invasive plants crowd landscape too threatening (trees provide out the native plants they depend on. perches for birds that prey on other birds) Examples of butterfly species often seen in to attract grassland‐obligate birds. Pennsylvania serpentine barrens1 include As a rule of thumb in the Mid‐Atlantic monarch, great spangled fritillary, region, grassland or meadow patches of 12

1 Anderson (1971) 2 Mulvihill et al. (2011) 39

to 25 acres sometimes support one or a few wren, cedar waxwing, indigo bunting, breeding pairs of a single grassland‐ American goldfinch, song sparrow, chipping obligate bird species, 25 to 50‐acre patches sparrow and field sparrow. do so more consistently, and it takes a No surveys of amphibians, turtles, minimum of 100 to 250 acres of contiguous snakes or mammals have been conducted open habitat, unbroken by hedgerows and at the Unionville Barrens. The probability is with few or no trees, to support multiple low (but not zero) that species in these grassland‐obligate bird species1. When fully groups listed as endangered, threatened3 or restored, the Unionville Barrens’ grassland otherwise of maintenance concern4 in is expected to cover upwards of 50 acres, Pennsylvania will be found there. but much of that area will be savanna, Regardless of the species’ conservation which is usually avoided as nesting habitat status, managers of a highly significant by grassland‐obligate species. However, as natural area should have as comprehensive cultivated fields elsewhere in the ChesLen as possible an understanding of what the Preserve are converted to grasslands resources they are managing consist of, dominated by native plants, the largest including the vertebrate species present. areas free of trees within the Unionville Amphibians in particular are declining Barrens might intermittently become home worldwide and many species—perhaps the to one or a few nesting pairs of grassland‐ majority—are now, or are on the verge of obligate birds spilling over from the larger becoming, species of special conservation habitat areas nearby. concern. The vernal pools, swamps and The Unionville Barrens are fully capable streams in and around the Unionville of providing habitat for birds with an Barrens doubtless support some affinity for grasslands and other specialized salamander, frog and toad species. The habitats that do not require large, treeless sooner these populations are surveyed the blocks. Pennsylvania’s Wildlife Action Plan2 better, in time for managers to consider identifies several species in this category as actions to prevent or reduce further being of “maintenance concern” statewide, declines and extirpations. One probable including brown thrasher, common factor in regional declines of terrestrial nighthawk, yellow‐breasted chat and salamander species is the proliferation of American woodcock. In addition to those invasive exotic earthworms, especially mentioned above as having an affinity for several newly established East Asian nearby large serpentine barrens (prairie species5. Acidic soils such as those typical of warbler, white‐eyed vireo, eastern towhee, dry oak – heath forest may be resistant to yellow‐breasted chat and American earthworm invasions. No mention has been woodcock), other such species include— made in the scientific literature of the but are not limited to—American kestrel, effects of eastern North American red‐tailed hawk, yellow‐shafted flicker, serpentine soils on earthworms6. The soil barn swallow, tree swallow, northern fauna of serpentine barrens is a subject ripe rough‐winged swallow, eastern bluebird, for scientific exploration. eastern kingbird, purple martin, house

3 Pennsylvania Natural Heritage Program (2010) 4 Pennsylvania Game Commission and Pennsylvania Fish 1 Peterjohn (2006) and Boat Commission (2005) 2 Pennsylvania Game Commission and Pennsylvania Fish 5 Maerz et al. (2009) and Boat Commission (2005) 6 Rajakaruna et al. (2009)

Desired Conditions, Indicators of Management Success, and Threats

3.1 Desired conditions 3Desired conditions are A bullet‐point summary of the desired attributes considered vital to conditions comes first, followed by a restoring and maintaining ecosystems to a narrative presenting additional details on high standard of ecological integrity. They desired conditions. The narrative is are based on current understanding of pre‐ organized in four broad subject areas: European‐settlement conditions, but they (1) desired species diversity and also take into account unavoidable composition, (2) desired structural, patch constraints on recreating historical and habitat diversity, (3) desired ecosystem conditions such as landscape isolation, processes, and (4) desired landscape invasive species populations, missing context. (extirpated or extinct) species that are Next is a table presenting a set of infeasible to restore, and other historical quantitative and highly specific metrics to changes at landscape and regional scales serve as the basis for monitoring. Ranges of beyond management area boundaries. values for each measured indicator are An essential element is a set of metrics ranked as excellent, good, fair or poor. or indicators used to evaluate and Where known, the present status in the communicate ecosystem conditions, with a Unionville Barrens is given for each metric. range of target values for each. Metrics are The last part of this section is an quantitative attributes of specific assessment of the major threats to ecosystem elements, measured at regular achieving and sustaining desired intervals to monitor conditions as they conditions. Stresses and stressors are change over time. described and ranked in terms of severity, The first four subsections give a scope and irreversibility. qualitative description of desired conditions for the Unionville Barrens. The 3.1.1 Qualitative summary of desired aim is to meet a high standard of ecological conditions integrity, with a particular focus on Desired conditions of serpentine sensitive habitats of imperiled, rare or barrens communities and landscape: declining species. • Total area of serpentine grassland An ecological system or species has integrity (including savanna and serpentine gravel … when its dominant ecological forb community) approaching 80% of characteristics (e.g., elements of composition, documented historical maximum, or structure, function and ecological processes) approximately 50 acres occur within their natural ranges of variation and can withstand and recover from most • Dominance by native herbaceous plant perturbations imposed by natural species characteristic of serpentine environmental dynamics or human grassland in all grassland patches 1 disruptions. • High within‐patch native serpentine grassland plant species diversity • High between‐patch diversity in native 1 Eckert (2009): p. 2 serpentine grassland plant species 41

composition, including variation in ° serpentine aster (PT; globally rare) which species are dominant • Recovery to secure population status of • Dominance by a mixture of oak species in at least 50% of the plant species of canopy and subcanopy of forest and special conservation concern formerly woodland surrounding serpentine present in the Unionville Barrens: grasslands ° colic‐root (PE) • Dominance by native woody species in ° slender three‐awn (TU) shrub layer of forest and woodland ° stiff tick‐trefoil (TU) surrounding serpentine grasslands ° slender crabgrass (SP) • High density of native tree seedlings, tree ° forked rush (PE) saplings and shrubs in shrub layer in ° downy lobelia (PE) patches totaling at least 50% of area of ° lion’s‐foot (PT) forest and woodland surrounding ° whip‐grass (PE) serpentine grasslands ° white heath aster (PT) • High within‐patch and between‐patch • Secure population status of animal species diversity of native tree seedlings, species of special conservation concern tree saplings, shrubs and herbaceous present in the Unionville Barrens plants in of forest and woodland Survey work is needed to identify what surrounding serpentine grasslands species are present. The initial focus • Dominance by native plant species in should be on arthropods, birds and wetlands amphibians because of the high • High within‐patch and between‐patch likelihood of finding rare or declining species diversity of native herbaceous species in those groups at the site. plants in wetlands Desired conditions of ecosystem resilience: Desired conditions of serpentine barrens plant and animal species of • Long‐term stability across entire range special conservation concern: of indicators • Secure population status of all plant • Stability of indicators following severe species of special conservation concern drought present at the Unionville Barrens: • Stability of indicators in the event of ° small‐leaf white‐snakeroot (PR) unforeseen major perturbation ° Elliott’s bluestem (PR) Desired conditions of landscape context: arrow‐feather three‐awn (PT) ° • 1,000‐foot smoke buffer with few houses ° side‐oats grama (PT) or other buildings ° Bicknell’s sedge (PE) ° Richardson’s sedge (PE) • 500‐foot seed dispersal buffer where ° New Jersey tea (SP) bird‐ and wind‐dispersed invasive species are kept in check ° barrens chickweed (SP) ° tufted hairgrass (PT) 3.1.2 Species diversity and composition ° Heller’s rosette grass (PT) ° long‐haired panic‐grass (PE) Plant species. The most dramatic change ° annual fimbry (PT) from current to desired conditions will be ° Bicknell’s hoary rockrose (PE) the resurgence of grassland from its ° rock sandwort (SP) current low of 7 acres in widely scattered ° Small’s ragwort (PR) patches, many very small, to broad ° round‐leaf fameflower (PT) expanses totaling 50 acres or more. The ° few‐flowered nut‐rush (PT) expansion of habitat is expected to halt the

ongoing decline and extirpation of conditions will depend partly on the grassland plant populations due to the outcomes of future animal surveys. twentieth‐century steep decline in habitat Indicators of wildlife habitat quality, area. It is also expected to restore the site’s include (but are not limited to): long‐term ability to support viable • secure populations of host plants for rare populations of declining species and of animals whose diets are narrowly extirpated species that may recolonize on limited to plant species restricted to a their own or be targets for reintroduction degree to serpentine barrens (examples from local seed sources. All of the plants of include wild indigo, New Jersey tea and special conservation concern will benefit by native warm‐season grasses) having more space to proliferate into larger—and therefore more resilient and • acreage of the serpentine grassland secure—populations (critically low community, where most plant hosts for population numbers are discussed further specialist insect herbivores live under Threats later in this section). • availability of dead tree snags for cavity‐ nesting animals (mainly eastern red‐ Another major change will be a sharp cedars killed but left standing) reduction in the abundance of invasive nonnative plants, especially autumn‐olive Monitoring will also include direct and stiltgrass, and a decrease in several observations of the animals themselves. native species, principally red maple, Indicators include all animal species of eastern red‐cedar and common greenbrier, special conservation concern, which first which have invaded the barrens and caused need to be identified in baseline surveys changes to soil and light conditions that are and then tracked over time in periodic detrimental to serpentine grassland plants. follow‐up surveys. Indicators also include species of highly visible animals—birds and Forests and woodlands will be restored butterflies—whose presence is associated to mixed oak dominance or a successional with the specialized habitats of the barrens trajectory of eventual oak species or whose populations are declining in the dominance by the thinning of competitive region. To date, the prairie leaf beetle is the trees, especially red maple, and by the only animal species of special conservation reduction of the outsized deer population, concern confirmed at the Unionville which is browsing oak seedlings to near‐ Barrens. Other arthropods of special total loss each winter (there is more on conservation concern are highly likely to be deer effects later under Threats). found through professional surveys Wetlands that have been increasingly conducted by qualified entomologists. Bird shaded by dense overtopping tree growth species of special conservation concern or will be exposed to more sunlight by tree whose populations are declining in the thinning and prescribed fire, fostering the region are also most likely present. return of shade‐intolerant native wetland species whose populations have been 3.1.3 Structural, patch and habitat reduced or extirpated. diversity Animal species. The particular value of the Clarification of terms. Structural diversity Unionville Barrens to wild animals is in is variety from place to place in community providing habitat for specialists that structure, which consists of the vertical depend on serpentine grasslands and oak‐ layering and horizontal arrangement of dominated forests or on small native plants of different sizes and growth forms, grasslands and scrubby vegetation in extent of canopy closure or bare ground, general. Assessing the current condition of and amounts and types of decomposing wildlife habitat and determining desired plant material on the ground. Patch 43

diversity is the variety of patch types within relatively high. The desired condition is still a community or ecosystem; a patch is a higher diversity in these factors, including relatively discrete area that is different in the return of large, open prairie patches, some significant way from its surroundings, that is, areas of one to several acres with for instance, in plant species composition, less than 10% tree cover. age since the last major disturbance, or Measures of success in achieving high community structure. Habitat diversity is a grassland and gravel forb community patch measure of the difference in species diversity include: composition among patches within a community and communities within a • plant species turnover (different landscape. Desired conditions generally composition) among patches maximize these three components of • frequency of patches with high plant diversity, within the parameters imposed species richness by other desired conditions such as overall • relative proportion of grassland (at least dominance by native species and secure 50% cover of native grasses) and population status of species of special serpentine gravel forb community (at conservation concern. least 50% cover of forbs) among patches High diversity in community structure • relative proportion of patches dominated and patch type is needed to accommodate a by short herbaceous plants and patches variety of plant and animal species. Such dominated by intermediate to tall diversity corresponds to some degree with herbaceous plants site features, for instance, spring seeps, • plant density variation among patches exposed bedrock, old mine tailings, and varied soil depth, slope steepness and • relative area of savanna versus prairie aspect. Patch diversity associated with (2) Serpentine seep, also globally rare, will differences in species dominance and expand in total area as tree and invasive composition also arises from variation in shrub cover is removed from spring seeps land‐use, disturbance and management and swales formerly dominated by its histories. Another important influence on shade‐intolerant characteristic species, patch diversity is the priority effect—which including tufted hairgrass, swamp thistle, species arrived and established first after a slender spikerush and New York ironweed. disturbance. The desired condition is a diverse mosaic of patch types differing in There is a low likelihood that its successional stage, species composition, reflectance signature on satellite imagery vegetation density and prevailing can be distinguished from that of the vegetation height. surrounding grassland but GPS‐assisted ground surveys in fall or spring may The communities with highest provide a feasible measure of total area. stewardship importance, in rank order by Besides increased area, desired conditions conservation priority, are: also include scarcity or absence of (1) Serpentine Indian‐grass – little nonnative species, high within‐patch bluestem grassland (including prairie and species diversity, and between‐patch savanna) and serpentine gravel forb variation in species composition, all of community are globally rare ecological which can be measured on a representative communities and have the highest priority sample of occurrences. for stewardship at the Unionville Barrens. (3) Mixed forb marsh is ranked high in Despite their greatly reduced area from the conservation priority at the Unionville historical peak, their diversity in structural, Barrens because its occurrences are patch and habitat attributes remains hotspots for native plant species diversity

and the core habitats for a high proportion forest differing in the relative abundances of the native plant species once found at the of the dominant species. site but now extirpated. Desired conditions The measures of success in applying are the same as for serpentine seep and can disturbance regimes to achieve and sustain be monitored on a representative sample of grassland and meadow desired conditions occurrences using the same indicators. are the indicators relating to grassland (4) Red maple – oak – greenbrier acreage and species diversity and serpentine forest and woodland, composition described elsewhere in this although globally rare, is lower in priority section. than other serpentine barrens‐restricted communities. Its species diversity and Fire. The halt in regularly recurring fire habitat value for species of special with the collapse and dispersal of American conservation concern are far lower than in Indian populations has been identified as serpentine grassland, which it has invaded the main cause of diminishing native plant and displaced through forest succession. species diversity in Midwestern prairie 1 Desired conditions include substantial remnants and almost certainly caused the reduction in the present‐day extent and loss of more than 99% of the land area lowered dominance by red maple and other formerly in native grasslands and meadows mesic forest species that alter soil from within the present‐day borders of 2 conditions and hasten further succession Pennsylvania soon after European contact . toward ordinary mesic forest. The desired There is little doubt that fires of result is higher oak dominance, in extreme severity were common through particular by the characteristic oaks of the evolutionary history of temperate serpentine barrens—post oak, blackjack eastern North American serpentine barrens oak and Bush’s oak in the canopy and dwarf even though they almost never occur today. chinkapin oak in the understory. Fire severity is associated with drought severity. There was little reason not to burn 3.1.4 Ecosystem processes during droughts before European Disturbance regime. Regular disturbance settlement; it is even possible that droughts is essential to maintain grasslands against were preferred times for burning because forest succession in most of eastern North of the boost in ecological impact toward America, with its year‐round moist climate. conditions desired by Native Americans. However, different disturbances can have Ever since rural fire suppression started in very different effects on grassland the mid‐twentieth century, fire has been ecosystems. Moreover, nuances of virtually excluded. Prescribed burning is disturbance type, seasonal timing, severity banned during all but the mildest of and frequency help to determine whether a drought conditions (for good reasons of grassland becomes a high‐dominance near‐ safety to life and property). monoculture (undesired) or a diverse mix The main distinction of high‐severity of many species (desired), or whether it fire is that it burns downward into the duff converges toward structural uniformity layer by extended smoldering, “cooking” (undesired) or diverges into a highly patchy the roots of shallow‐rooted plants, killing environment that can accommodate the part of the seed bank, and leaving the soil habitat needs of many species (desired). highly vulnerable to erosion in the early Patchiness at a range of scales is desired, post‐fire period—all of which are beneficial from 100–1,000‐square foot gravel forb to the long‐term persistence of serpentine and serpentine seep communities or localized stands of a rare species to 1–10‐ 1 Leach and Givnish (1996) acre patches of grassland, woodland or 2 Latham (2005) 45

barrens‐restricted species and serpentine although dominated by herbaceous species, grassland, gravel forb and seep commu‐ was not serpentine grassland. Surviving nities. Lower‐severity fires, including greenbrier rhizomes restored the thickets typical prescribed burns, are essential for within a year or two after the goats were the long‐term maintenance of serpentine removed1. Although prescribed browsing barrens but they cannot replicate all of the or grazing should not be ruled out as a effects of the fires that fostered and management method to be tested in future sustained those communities throughout adaptive management trials, logistical and most of their history. Prescribed burning cost challenges such as the need for fencing crews may be able to achieve high severity and veterinary care make it an unlikely in limited areas under controlled conditions routine management method in the where fuel loads are high enough and Unionville Barrens’ future. moisture levels low enough to ignite duff Selective herbivory associated with and prolong smoldering overnight, with long‐term deer superabundance is unlike round‐the‐clock monitoring to insure any disturbances listed in the preceding flare‐ups do not result in loss of control. paragraphs in at least two ways: its source Once feasibility is demonstrated, rotating is the target of an active reduction effort— severe fire among selected areas could be a the ChesLen Preserve’s deer management powerful tool for maintaining desired patch program; and herbivory by deer is a threat diversity. to desired conditions at high deer Soil reduction. The desired effects of population density. Unlike fenced or severe fire can be simulated in part by tethered livestock, deer numbers and mechanical soil organic matter removal intensity of browsing pressure are difficult with off‐site disposal. Outstandingly to regulate, their effects on vegetation positive results at several other Northern cannot be targeted only where desired on Piedmont serpentine barrens make this the the landscape for management purposes, method of choice where repeated burning and it is impractical to exclude them except fails to produce desired conditions within a from small areas. Deer herbivory is treated reasonable period in a localized area. under Threats (pp. 61–66) However, cost and other constraints, such Soil dynamics. The key desired soil change as difficult terrain for access by large is a reversal of the accumulation of soil machinery, make this a method only to be organic matter and associated increases in applied judiciously in limited areas. nutrient availability and moisture‐holding Grazing and browsing. Historically, capacity over the past century in the areas grazing by cattle has had positive effects in where tree and shrub cover has replaced sustaining serpentine grassland through grassland. This is equivalent to re‐ extended periods of fire exclusion at many, intensifying the serpentine soil syndrome if not all sites. This has been observed most and reducing macronutrient availability. recently or is best documented at the New A short‐term increase in the rate of soil Texas Barrens, Chrome Barrens and Pink erosion from the hilltops and upper slopes Hill. Prescribed browsing and grazing by (and deposition downslope and on stream goats has been employed at a small scale as floodplains) will be encouraged as the a serpentine grassland restoration tool in ground surface is exposed to the full force three‐year trials at the Nottingham Barrens, of rain and runoff following restoration with disappointing results. Goats browsed burning and soil scarification by machinery dense thickets of common greenbrier to the point where no aboveground parts were visible but the succeeding vegetation cover, 1 Latham and Thorne (1997); R. E. Latham, unpublished data

used to remove trees and invasive shrubs. and soil thickness. In general in terrestrial These disturbances will increase organic ecosystems, lower soil fertility is associated matter decomposition rates as soil surfaces with lower dominance (higher species blackened by fires increase soil evenness) and lower competition, which at temperature and the easily decomposed the Unionville Barrens should translate to fine roots of cut trees and fire‐killed plants higher native species richness and feed soil microbes. Accelerated soil organic increases in serpentine grassland‐restricted matter decomposition and erosion will plant populations. decrease soil thickness. Ecological resilience. “The ability of a Erosion rates are likely to level off later, system to absorb disturbance and still after a switch to the longer fire return retain its basic function and structure” is a intervals associated with maintenance general definition of resilience1. Ecologists burning and the spread of cover by native commonly use the term resilience with two perennial warm‐season grasses, with their more‐restricted meanings. One is the speed dense, rain‐intercepting foliage and deep, at which an ecosystem returns to its former fibrous root systems. As restored state after it has been displaced from that grasslands mature, the desired trajectory of state by a disturbance; the other is the soil development is a gradual shift of some amount of disturbance required to push an soil nutrients now in labile forms into living ecosystem over a threshold onto a biomass and more‐recalcitrant litter successional pathway leading to different (including charcoal), which bind up some of persistent state2. The former lends itself to the macronutrient pool for long periods. measurement. This makes macronutrients less available to Resilience has no separate metrics from highly nutrient‐demanding species, which those of other desired conditions. Instead, include most invasive nonnatives. its measure is the speed of recovery among The forested headwater stream all of those metrics following severe ecosystems will unavoidably undergo some droughts or other major perturbations. It is degradation during this rearrangement of also the stability of those indicators in the soil and organic matter. This trade‐off in face of ongoing climate change. desired conditions is made necessary by Climate change. Changes in species the higher priority placed on the globally composition and other ecosystem rare serpentine barrens communities attributes due to climate change hinge on compared with the more common forested the characteristics of many individual headwater stream community. The streams species and therefore are difficult to predict are expected to rebound to near starting accurately and in detail3. The best anyone conditions or better as newly expanded can do is a set of educated guesses based on grasslands and gravel forb communities the fossil record during past climate mature, becoming increasingly effective at changes and knowledge of living species’ stabilizing soil and filtering runoff. tolerances and habitat preferences. There is However, because of their lower priority every reason to expect that serpentine and the high demands of monitoring the barrens’ resilience to climate change will be highest priority communities and species, high. Experimental simulations show that no monitoring of stream indicators is resilience depends on the particular set of suggested at this time. species present; however, there is evidence Metrics relating to plant species diversity and composition will reflect the 1 desired shift to heightened serpentine soil Walker and Salt (2006): p. 1 2 Eckert (2009) syndrome effects and decreased fertility 3 Graham and Grimm (1990) 47

that mature, native grasslands are highly forests similar to those currently resilient and successional or newly widespread in the Atlantic Coastal Plain reclaimed grasslands considerable less and Piedmont to the east and south. The resilient to the likely effects of climate oak forests of the Unionville Barrens are change, which include elevated CO2 levels, likely to be among the most resilient of higher temperatures, more‐variable local forest types, because they are already precipitation, and longer droughts1. dominated by species with relatively high Native grasslands and meadows in tolerance for intermittent drought. general are likely to be more resilient than 3.1.5 Landscape context forests to disruption by global climate change. As climate warms and droughts Smoke buffer. Prescribed burning can be become more severe and frequent, applied most effectively if there is a large grassland is likely to need less intensive buffer zone around all potential burn units management to resist forest succession. within which there are no houses or other Drought kills tree seedlings and saplings at occupied buildings. Smoke and hazard higher rates than upland grassland plants management are critical issues in and in so doing, slows succession. Warming prescribed burning. The wider and more and wider variation in precipitation almost completely encircling the buffer zone is, the certainly will lead to changes in species less severe the constraints are on how composition, depending on localized (patch many days are available for burning due to scale) conditions. More severe rainstorms wind direction, and the lower the likelihood and less precipitation as snow may increase is that a burn already in progress will need soil erosion locally. Drought‐tolerant to be shut down because of an unexpected species are expected to increase in cover wind shift. An adequate buffer also and dominance while moisture‐demanding minimizes risk to life and property in case species contract. In the long term, the of escape. Ideally, new construction will be expectation is of range expansions restricted by easement or fee purchase so northward of southern species (additions that no more houses may be built within at to the local flora), some with a human least 1,000 feet of any management unit assist, and range contractions northward of boundary (see Map 10). Township zoning is northern species (local extirpations). another means of limiting new construction, but it is less reliable in the Serpentine barrens have long been long term because it is subject to variances famous as collections of disjunct or “island” and amendments. populations of species whose main ranges are in the hotter Southeast, in the drier Seed dispersal buffer. Most seeds fall Midwest, or on the sandy, low‐nutrient, close to the parent plant, but for species more drought‐prone soils of the Atlantic capable of long‐distance dispersal, mainly Coastal Plain. Grassland community by birds or wind, a relatively concentrated changes are likely to be less dramatic in the “seed shadow” may extend several hundred face of expected climate change than those feet (only a very small proportion of seeds in surrounding Northern Piedmont forests, are carried farther). Success in managing where some forest types may decline, invasive species in the barrens and adjacent especially in well‐drained soils and on high‐quality oak forests will depend in part south‐facing slopes, possibly with gradual on eradicating those plants or reducing replacement by mixed pine‐deciduous them as much as possible in the surround‐ ing area and targeting new colonies as they arise. It is assumed that doing so in a zone 1 Grime et al. (2000); Adler et al. (2006); Engel et al. 500 feet wide surrounding management (2009)

unit boundaries will substantially reduce century ago1. “Phytometers” remain one of the effort needed to manage invasive the most effective and efficient ways of species in core areas of grassland and high‐ tracking the complexities of ecosystem quality oak forest stands. At present in and conditions and dynamics. around the Unionville Barrens, the most Using selected attributes of individual common invasive species in the category of plants, populations or entire communities long‐distance dispersers are autumn‐olive, as assessment tools in ecological research Japanese barberry, Oriental bittersweet, and monitoring is based on the idea that Japanese honeysuckle, Amur honeysuckle, plant responses integrate a multitude of Morrow’s honeysuckle, multiflora rose, physical, chemical and other environmental wineberry, winged euonymus (burning‐ factors and their complex interactions. bush), border privet, tea viburnum, mile‐a‐ When measured or counted at regular minute and Canada thistle. intervals they can better reflect ecosystem 3.1.6 Metrics of ecosystem condition— conditions and be more predictive of trends the phytometer approach than direct measurements of abiotic factors, whose interactive effects on The Unionville Barrens are important ecosystem components are often poorly enough that they merit a higher intensity of understood. Measuring phytometers takes monitoring effort than most NLT preserves. the place of guessing which environmental NLT’s management of the Unionville factors are important, how they rank Barrens will have global consequences relative to each other, and in what intricate because the site harbors several globally ways they may counteract or intensify each rare communities, one globally rare plant other’s effects. Most of the indicators and possibly one to several globally rare recommended in this report are insect species. It also is home to at least 17 phytometric (Table 7). other plant species and possibly a similar number of animal species of special Attributes of animal populations also conservation concern in Pennsylvania. The can be important indicators of ecosystem metrics recommended here (Table 7, pp. conditions, but in most cases they are much 50–59) seem complex at first reading, but more difficult, expensive and time‐ most of them can be calculated from simple consuming to count or measure. Unlike estimates of plant species cover on a set of plants, animals rarely submit docilely to permanent monitoring quadrats, which measurement or stay in the same place need only to be surveyed every 3–5 years. until the next monitoring occasion. Also, because of the site’s importance it is However, unlike the majority of animal urgent that resources and qualified species, grassland birds and butterflies are personnel are deployed soon to conduct conspicuous and diurnal and some bird‐ baseline arthropod and bird surveys and a related attributes may be monitored by system put in place for follow‐up surveys at sound as well as sight. Several animal appropriate intervals. metrics are recommended for at least occasional monitoring (Table 7). Plants are the dominant organisms in nearly all non‐aquatic ecosystems and In some monitoring situations it is certain attributes of their performance are essential to include metrics of one or more effective proxies for many aspects of whole‐ physical, chemical or other abiotic factors, ecosystem condition. Plants and ecological in particular where such a factor has a communities have been used as ecological (continued on p. 60) measuring instruments since nearly a

1 Clements and Goldsmith (1924) 49

Table 7. Desired conditions, metrics, target values and existing conditions of the Unionville Barrens. See Table A‐2, Appendix A (p. 110) for meanings of codes in parentheses after species names. See text (pp. 60–61) for methods used to derive target values.

desired condition metric (= indicator) & suggested monitoring interval target values present condition ECOLOGICAL COMMUNITIES AND LANDSCAPE 1. Total area of grassland + EXCELLENT ≥ 45 acres GIS computation of area based on recent high‐ gravel forb community + GOOD 35–44.9 acres POOR resolution (1‐m/3‐foot or better) satellite imagery— serpentine seep approaching 45 FAIR 25–34.9 acres every 2–3 years 7 acres acres POOR < 25 acres 2. Ample proportion of serpen‐ GIS computation of area based on recent high‐ EXCELLENT ≥ 20% tine gravel forb community (vs. resolution (1‐m/3‐foot or better) satellite imagery, GOOD 15%–19.9% unknown; grassland & wetland) in total assuming image classification software can be used to FAIR 10%–14.9% possibly GOOD herbaceous‐dominated area reliably separate the communities—every 3–5 years POOR < 10% EXCELLENT 50%–80% GIS computation of area based on recent high‐ 3. Intermediate to high (but not GOOD 40%–49.9% or resolution (1‐m/3‐foot or better) satellite imagery, too high) proportion of prairie 80.1%–85% POOR counting only prairie (< 10% tree cover) polygons that (vs. savanna) in total area of FAIR 30%–39.9% or < 30% can fully enclose a circle ≥ 1 acre (≥ 236‐foot grassland 85.1%–90% diameter)—every 3–5 years POOR < 30% or > 90% 4. Dominance by native Average percent of total plant cover in herbaceous EXCELLENT 95%–100% probably herbaceous serpentine grassland serpentine grassland species per 5‐m × 5‐m GOOD 90%–94.9% GOOD to plant species in all grassland monitoring quadrat (100 × sum of percent cover of FAIR 85%–89.9% EXCELLENT patches those species ÷ sum of all species)—every 3–5 years POOR < 85% EXCELLENT ≥ 20 unknown; Average richness (α) of native serpentine grassland GOOD 15–19.9 possibly plant species per 5‐m × 5‐m monitoring quadrat— FAIR 10–15.9 GOOD to every 3–5 years POOR < 10 EXCELLENT EXCELLENT 30–100 unknown; 5. High within‐patch native Average evenness (E ) of all plant species per 5‐m × GOOD 24–29.9 possibly serpentine grassland plant 1/D 5‐m monitoring quadrat—every 3–5 years FAIR 18–23.9 GOOD to species diversity POOR < 18 EXCELLENT EXCELLENT 36–100 unknown; Upper quartile of evenness of all plant species per 5‐m GOOD 30–35.9 possibly × 5‐m monitoring quadrat—every 3–5 years FAIR 24–29.9 GOOD to POOR < 24 EXCELLENT

desired condition metric (= indicator) & suggested monitoring interval target values present condition EXCELLENT 15–100 unknown; Herbaceous serpentine grassland plant species GOOD 12–14.9 possibly turnover (βH) among 25‐m2 monitoring quadrats— FAIR 9–11.9 GOOD to 6. High between‐patch diversity every 3–5 years in native serpentine grassland POOR < 9 EXCELLENT plant species composition, Upper quartile of herbaceous serpentine grassland EXCELLENT ≥ 25 unknown; including dominant species GOOD 20–24.9 possibly plant species richness per 25‐m2 monitoring quadrat— FAIR 15–19.9 GOOD to every 3–5 years POOR < 15 EXCELLENT

Average αE – αA as a percentage of αE, where αE = EXCELLENT ≤ 5% native grassland forb richness per fenced deer GOOD 5.1%–10% not yet 7. Herbivory by white‐tailed deer exclosure and αA = grassland forb richness per FAIR 10.1%–15% measured at a level that does not depress adjacent monitoring quadrat POOR > 15%

diversity of native grassland Average E E – E A as a percentage of E E, where E E = total EXCELLENT ≤ 5% forbs grassland species evenness per fenced deer exclosure GOOD 5.1%–10% not yet and E A = total grassland species evenness per adjacent FAIR 10.1%–15% measured monitoring quadrat POOR > 15% 8. Dominance by a mixture of oak EXCELLENT 90%–100% Average percent of total canopy cover in oaks per unknown; species in woods (forest and GOOD 80%–89.9% 25‐m2 monitoring quadrat (100 × sum of percent cover possibly woodland) canopy and FAIR 70%–79.9% of those species ÷ sum of all species)—every 3–5 years FAIR to GOOD subcanopy POOR < 70% Average percent of shrub and ground layer (< 2 m EXCELLENT 90%–100% 9. Dominance by native plants in unknown; height) plant cover in native species per 25‐m2 GOOD 80%–89.9% woods (forest and woodland) possibly monitoring quadrat (100 × sum of percent cover of FAIR 70%–79.9% shrub and ground layer POOR native species ÷ sum of all species)—every 3–5 years POOR < 70% 10. High density of native tree Average aggregate percent cover of native tree EXCELLENT > 90% unknown; seedlings and saplings in patches seedlings & saplings per 25‐m2 monitoring quadrat, GOOD 80%–89.9% possibly totaling at least 50% of area of counting only the 50% of quadrats with the highest FAIR 70%–79.9% POOR woods aggregate percent cover—every 3–5 years POOR < 70% Average aggregate percent cover of native shrubs per EXCELLENT > 90% 11. High density of native shrubs unknown; 25‐m2 monitoring quadrat, counting only the 50% of GOOD 80%–89.9% in patches totaling at least 50% possibly quadrats with the highest aggregate percent cover— FAIR 70%–79.9% of area of woods POOR every 3–5 years POOR < 70%

51 (Table continues on next page.) 52 Table 7 (continued)

desired condition metric (= indicator) & suggested monitoring interval target values present condition EXCELLENT ≥ 20 Average richness (α) of native tree seedlings, saplings, unknown; GOOD 15–19.9 shrubs and herbaceous plant species per 25‐m2 possibly FAIR 10–15.9 monitoring quadrat—every 3–5 years POOR to FAIR POOR < 10 12. High within‐patch species EXCELLENT 30–100 Average evenness (E1/D) of all tree seedlings, saplings, unknown; diversity of native tree seedlings, GOOD 24–29.9 shrubs and herbaceous plant species per 25‐m2 possibly saplings, shrubs and herbaceous FAIR 18–23.9 monitoring quadrat—every 3–5 years POOR to FAIR plants in woods POOR < 18 EXCELLENT 36–100 Upper quartile of evenness of all tree seedlings, unknown; GOOD 30–35.9 saplings, shrubs and herbaceous plant species per possibly FAIR 24–29.9 25‐m2 monitoring quadrat—every 3–5 years POOR to FAIR POOR < 24 EXCELLENT 15–100 unknown; Native plant species turnover ( ) among 25‐m2 GOOD 12–14.9 βH possibly monitoring quadrats—every 3–5 years FAIR 9–11.9 13. High between‐patch species FAIR to GOOD diversity of native tree seedlings, POOR < 9 saplings, shrubs and herbaceous EXCELLENT ≥ 25 unknown; plants in woods Upper quartile of native plant species richness per GOOD 20–24.9 possibly 25‐m2 monitoring quadrat—every 3–5 years FAIR 15–19.9 FAIR to GOOD POOR < 15 Average percent of total herbaceous plant cover in EXCELLENT 90%–100% 14. Dominance by native unknown; native herbaceous species per 25‐m2 monitoring GOOD 80%–89.9% herbaceous plant species in possibly quadrat (100 × sum of percent cover of those species ÷ FAIR 70%–79.9% wetlands POOR to FAIR sum of all species)—every 3–5 years POOR < 70% EXCELLENT ≥ 20 unknown; Average richness ( ) of native herbaceous plants per GOOD 15–19.9 α possibly wetland patch—every 3–5 years FAIR 10–15.9 POOR to FAIR 15. High within‐patch species POOR < 10 diversity of native herbaceous EXCELLENT 30–100 plants in wetlands unknown; Average evenness (E ) of all plant species per GOOD 24–29.9 1/D possibly wetland patch—every 3–5 years FAIR 18–23.9 POOR to FAIR POOR < 18

desired condition metric (= indicator) & suggested monitoring interval target values present condition EXCELLENT 36–100 unknown; Within‐patch diversity in Upper quartile of evenness of all plant species per GOOD 30–35.9 possibly wetlands (continued) wetland patch—every 3–5 years FAIR 24–29.9 POOR to FAIR POOR < 24 EXCELLENT 15–100 16. High between‐patch species unknown; Native herbaceous plant species turnover ( ) among GOOD 12–14.9 diversity of native herbaceous βH possibly wetland patches—every 3–5 years FAIR 9–11.9 plants in wetlands FAIR to GOOD POOR < 9 PLANTS OF SPECIAL CONSERVATION CONCERN EXCELLENT ≥ 4 Discrete clusters at least 500 apart—every 2–3 years GOOD 3 POOR until GOOD, then every 3–5 years FAIR 2 1 known 17. Secure population status of POOR 1 Bicknell’s sedge (PE) EXCELLENT ≥ 10,000 Estimated total number of tufts—every 2–3 years until GOOD 1,000–9,999 POOR GOOD, then every 3–5 years FAIR 100–999 ~ 25 known POOR < 100 EXCELLENT ≥ 4 Discrete clusters at least 500 apart—every 2–3 years GOOD 3 POOR until GOOD, then every 3–5 years FAIR 2 1 known 18. Secure population status of POOR 1 Richardson’s sedge (PE) EXCELLENT ≥ 10,000 Estimated total number of tufts—every 2–3 years until GOOD 1,000–9,999 POOR GOOD, then every 3–5 years FAIR 100–999 est. 10–100 POOR < 100 EXCELLENT ≥ 4 Discrete clusters at least 500 apart—every 2–3 years GOOD 3 unknown until GOOD, then every 3–5 years FAIR 2 19. Secure population status of POOR 1 long‐haired panic‐grass (PE) EXCELLENT ≥ 10,000 probably Estimated total number of tufts—every 2–3 years until GOOD 1,000–9,999 FAIR GOOD, then every 3–5 years FAIR 100–999 est. 100–1,000 POOR < 100

53 (Table continues on next page.) 54 Table 7 (continued)

desired condition metric (= indicator) & suggested monitoring interval target values present condition EXCELLENT ≥ 4 Discrete clusters at least 500 apart—every 2–3 years GOOD 3 POOR until GOOD, then every 3–5 years FAIR 2 1 20. Secure population status of POOR 1 Bicknell’s hoary rockrose (PE) EXCELLENT ≥ 1,000 Estimated total number of stems—every 2–3 years GOOD 100–999 POOR to FAIR until GOOD, then every 3–5 years FAIR 10–99 est. ~ 10 POOR < 10 EXCELLENT ≥ 4 GOOD 3 probably Discrete clusters at least 500 apart—every 3–5 years FAIR 2 GOOD 21. Secure population status of POOR 1 arrow‐feather three‐awn (PT) EXCELLENT ≥ 100,000 probably GOOD 10,000–99,999 Estimated total number of tufts—every 3–5 years FAIR to GOOD FAIR 1,000–9,999 est. > 5,000 POOR < 1,000 EXCELLENT ≥ 4 GOOD 3 probably Discrete clusters at least 500 apart—every 3–5 years FAIR 2 FAIR 22. Secure population status of POOR 1 side‐oats grama (PT) EXCELLENT ≥ 100,000 probably GOOD 10,000–99,999 Estimated total number of tufts—every 3–5 years FAIR FAIR 1,000–9,999 est. > 5,000 POOR < 1,000 EXCELLENT ≥ 4 GOOD 3 EXCELLENT Discrete clusters at least 500 apart—every 3–5 years FAIR 2 >4 23. Secure population status of POOR 1 tufted hairgrass (PT) EXCELLENT ≥ 10,000 GOOD GOOD 1,000–9,999 Estimated total number of tufts—every 3–5 years est. 1,000– FAIR 100–999 5,000 POOR < 100

desired condition metric (= indicator) & suggested monitoring interval target values present condition EXCELLENT ≥ 4 GOOD 3 probably Discrete clusters at least 500 apart—every 3–5 years FAIR 2 EXCELLENT 24. Secure population status of POOR 1 Heller’s rosette grass (PT) EXCELLENT ≥ 10,000 probably GOOD 1,000–9,999 Estimated total number of tufts—every 3–5 years FAIR FAIR 100–999 est. 100–1,000 POOR < 100 EXCELLENT ≥ 4 GOOD 3 probably Discrete clusters at least 500 apart—yearly FAIR 2 EXCELLENT 25. Secure population status of POOR 1 annual fimbry (PT) EXCELLENT ≥ 10,000 probably GOOD 1,000–9,999 GOOD Estimated total number of individuals—yearly FAIR 100–999 est. 1,000– POOR < 100 5,000 EXCELLENT ≥ 4 probably GOOD 3 Discrete clusters at least 500 apart—every 3–5 years GOOD to FAIR 2 EXCELLENT 26. Secure population status of POOR 1 round‐leaf fameflower (PT) EXCELLENT ≥ 1,000 GOOD 100–999 FAIR to GOOD Estimated total number of stems—every 3–5 years FAIR 10–99 est. 50–500 POOR < 10 EXCELLENT ≥ 4 GOOD 3 EXCELLENT Discrete clusters at least 500 apart—every 3–5 years FAIR 2 >4 27. Secure population status of POOR 1 few‐flowered nut‐rush (PT) EXCELLENT ≥ 10,000 GOOD to GOOD 1,000–9,999 Estimated total number of tufts—every 3–5 years EXCELLENT FAIR 100–999 est. > 5,000 POOR < 100

55 (Table continues on next page.) 56 Table 7 (continued)

desired condition metric (= indicator) & suggested monitoring interval target values present condition EXCELLENT ≥ 4 GOOD 3 EXCELLENT Discrete clusters at least 500 apart—every 3–5 years FAIR 2 >4 28. Secure population status of POOR 1 serpentine aster (PT; globally EXCELLENT ≥ 10,000 rare) GOOD to GOOD 1,000–9,999 Estimated total number of stems—every 3–5 years EXCELLENT FAIR 100–999 est. > 5,000 POOR < 100 EXCELLENT ≥ 4 GOOD 3 EXCELLENT Discrete clusters at least 500 apart—every 3–5 years FAIR 2 >4 29. Secure population status of POOR 1 small‐leaf white‐snakeroot (PR) EXCELLENT ≥ 10,000 GOOD to GOOD 1,000–9,999 Estimated total number of stems—every 3–5 years EXCELLENT FAIR 100–999 est. > 5,000 POOR < 100 EXCELLENT ≥ 4 Discrete clusters at least 500 apart—every 2–3 years GOOD 3 POOR until GOOD, then every 3–5 years FAIR 2 1 30. Secure population status of POOR 1 Elliott’s beardgrass (PR) EXCELLENT ≥ 10,000 Estimated total number of tufts—every 2–3 years until GOOD 1,000–9,999 POOR GOOD, then every 3–5 years FAIR 100–999 est. ~ 10 POOR < 100 EXCELLENT ≥ 4 GOOD 3 EXCELLENT Discrete clusters at least 500 apart—every 3–5 years FAIR 2 >4 31. Secure population status of POOR 1 Small’s ragwort (PR) EXCELLENT ≥ 10,000 GOOD to GOOD 1,000–9,999 Estimated total number of stems—every 3–5 years EXCELLENT FAIR 100–999 est. > 5,000 POOR < 100

desired condition metric (= indicator) & suggested monitoring interval target values present condition EXCELLENT ≥ 4 Discrete clusters at least 500 apart—every 2–3 years GOOD 3 unknown until GOOD, then every 3–5 years FAIR 2 32. Secure population status of POOR 1 New Jersey tea (SP) EXCELLENT ≥ 2,500 Estimated total number of stems—every 2–3 years GOOD 500–2,499 POOR to FAIR until GOOD, then every 3–5 years FAIR 100–499 est. 50–100 POOR < 100 EXCELLENT ≥ 4 GOOD 3 EXCELLENT Discrete clusters at least 500 apart—every 3–5 years FAIR 2 >4 33. Secure population status of POOR 1 barrens chickweed (SP) EXCELLENT ≥ 10,000 GOOD to GOOD 1,000–9,999 Estimated total number of stems—every 3–5 years EXCELLENT FAIR 100–999 est. > 5,000 POOR < 100 EXCELLENT ≥ 4 GOOD 3 EXCELLENT Discrete clusters at least 500 apart—every 3–5 years FAIR 2 >4 34. Secure population status of POOR 1 rock sandwort (SP) EXCELLENT ≥ 10,000 Estimated total number of individuals—every 3–5 GOOD 1,000–9,999 GOOD years FAIR 100–999 est. > 5,000 POOR < 100 EXCELLENT ≥ 4 GOOD 3 Each species: discrete clusters at least 500 apart unknown 35. Secure population status of FAIR 2 each other plant species of POOR 1 special conservation concern found in surveys or reintroduced EXCELLENT GOOD contingent from nearby seed sources Each species: estimated total number of stems unknown FAIR on species POOR

57 (Table continues on next page.) 58 Table 7 (continued)

desired condition metric (= indicator) & suggested monitoring interval target values present condition LARVAL HOST PLANTS FOR LEPIDOPTERA OF SPECIAL CONSERVATION CONCERN EXCELLENT ≥ 4 GOOD 3 GOOD to Discrete clusters at least 500 apart FAIR 2 EXCELLENT 36. Secure population status of POOR 1 moss‐phlox EXCELLENT ≥ 10,000 GOOD 1,000–9,999 FAIR to GOOD Estimated total number of plants FAIR 100–999 est. 500–5,000 POOR < 100 EXCELLENT ≥ 4 Discrete clusters at least 500 apart—every 2–3 years GOOD 3 unknown until GOOD, then every 3–5 years FAIR 2 Secure population status of New POOR 1 Jersey tea (same as 32, above) EXCELLENT ≥ 2,500 Estimated total number of stems—every 2–3 years GOOD 500–2,499 POOR to FAIR until GOOD, then every 3–5 years FAIR 100–499 est. 50–100 POOR < 100 EXCELLENT ≥ 45 acres Secure population status of all Use total area dominated by native serpentine GOOD 35–44.9 acres POOR native warm‐season grasses in grassland plant species as proxy FAIR 25–34.9 acres aggregate (same as 1, above) 7 acres POOR < 25 acres ARTHROPOD SPECIES OF SPECIAL CONSERVATION CONCERN EXCELLENT Each species: number of individuals captured by GOOD contingent unknown 37. Presence and detection standardized methods—every 3–5 years FAIR on species frequency of individual POOR arthropod species of special EXCELLENT Each species: variation from previous surveys in conservation concern GOOD contingent number of individuals captured by standardized unknown FAIR on species methods (population increase, decrease or stability) POOR

desired condition metric (= indicator) & suggested monitoring interval target values present condition BIRD SPECIES OF SPECIAL CONSERVATION CONCERN EXCELLENT ≥ 15 Each species: verified nesting pairs in Unionville GOOD 10–14 unknown Barrens—yearly FAIR 5–9 38. Secure breeding status of POOR < 5 individual bird species of special EXCELLENT < 10% decline conservation concern (e.g., Each species: variation in number of verified nesting GOOD 10%–14.9% decline brown thrasher, common pairs from average over previous 3 years (short‐term unknown FAIR 15%–19.9% decline nighthawk, yellow‐breasted population increase, decrease or stability) POOR ≥ 20% decline chat) found nesting at the site in EXCELLENT ≤ 0% decline surveys Each species: variation in number of verified nesting GOOD 0.1%–5% decline pairs from average over previous 15 years (long‐term unknown FAIR 5.1%–10% decline population increase, decrease or stability) POOR > 10% decline ECOSYSTEM RESILIENCE to be 39. Relatively rapid recovery of EXCELLENT ≤ 3 years calculated Each indicator: speed of recovery after disturbance indicators 4–38 (above) GOOD 4–5 years across severe enough to cause degradation of at least 50% of following severe drought or FAIR 6–7 years sequential indicators to lower target values category other major disturbance POOR > 7 years monitoring intervals LANDSCAPE CONTEXT Land area within 1,000 feet of management unit EXCELLENT 298–301 acres 40. Protected smoke and safety perimeter (out of 301 total acres in this zone) GOOD 271–297 acres buffer within 1,000 feet of all protected against additional building construction by unknown FAIR 226–270 acres management units zoning, easement, land trust ownership or public POOR < 226 acres ownership 41. Low populations of bird‐ Estimated area within 500 feet of management unit EXCELLENT 0–6 acres and wind‐ dispersed invasive perimeter (out of 135 total acres in this zone) where GOOD 7–13 acres nonnative plant species within cover of invasive nonnative plants of species with bird‐ unknown FAIR 14–20 acres 500 feet of all management and wind‐dispersed seeds (see list of locally common POOR > 20 acres units species on p. 64) exceeds 10%.

strong effect and is likely to undergo rapid and maintaining ecosystem integrity is not change. That is more often true of aquatic an either/or proposition; success is better ecosystems than those on land; for viewed as something that is achieved by instance, in streams and lakes certain water gradual progress from less‐desired to chemistry attributes can change quickly more‐desired conditions. Part of the and such change can bring about massive reward and satisfaction in natural land changes in species composition and other stewardship is achieving milestones along ecosystem conditions. At present no abiotic that path. Systematically measuring indica‐ metric is considered to be essential for tors is a way of cataloging and honoring effective monitoring of ecosystem those milestones. conditions in the Unionville Barrens, but Most indicators of desired conditions at unforeseen circumstances could change the scale of ecological communities and that state of affairs at some future time. landscapes (Table 7, items 4–16) and Ecological indicators. According to a populations of plants of special seminal paper, indicators of ecological conservation concern that occur in high integrity and management success abundance at the site (items 21–29, 31–34, need to capture the complexities of the 36 and 39) can be calculated from the ecosystem yet remain simple enough to be results of a single periodic monitoring task, easily and routinely monitored. Ecological namely, surveying plant species cover in indicators should meet the following criteria: scattered, permanently marked quadrats. A be easily measured, be sensitive to stresses few sparsely distributed plants of special on the system, respond to stress in a conservation concern (items 17–20, 30 and predictable manner, be anticipatory, predict 39) will not be picked up by quadrats and changes that can be averted by management will require special surveys targeting actions, be integrative, have a known known clusters of individuals. Some response to disturbances, anthropogenic stresses, and changes over time, and have landscape‐scale indicators are measured by low variability in response.1 GIS analysis of satellite imagery (items 1– 3). Skilled amateur volunteers can be The most effective metrics for learning pressed into service to monitor bird whether management methods need to be indicators (item 38). Professional modified or new methods tried are quick‐ entomologists must be employed to track response indicators—those that respond arthropod indicators (item 37). Details are rapidly to any escalation or decline in presented in the next section under stresses and to management actions taken Monitoring (pp. 80–84) and in Appendix D to remedy those stresses. (pp. 149–153). Instead of defining a single threshold Methods for setting target values. value separating “acceptable” from Desired condition metrics and target values “unacceptable” for each metric, we describe involving plant species diversity, combined potential values of indicators in terms of cover of species functional groups, ranges of variation and split the ranges into community structure, patchiness and segments ranked excellent, good, fair or habitat for animals of special conservation poor. One reason for bringing ranges of concern were developed based on variation into play is that fluctuation over quantitative analyses of plant species cover time in most of the key ecological attributes data from the few relevant reference sites is natural and expected and not inconsis‐ for which such data are available. tent with high ecosystem integrity. Equally Nottingham Barrens contain the only importantly, judging success in restoring serpentine grassland with available pertinent data; data from two other major 1 Dale and Beyeler (2001), p. 3

grassland areas in southeastern Pennsyl– Metrics and target values at the level of vania were also included in the analyses1. whole landscapes, such as total serpentine Because so little pertinent data exist, grassland area and proportions of much professional judgment is involved; grassland in prairie, savanna and gravel therefore ranking of target values into forb community, were developed from ranges identified as poor, fair, good and historical descriptions of Northern excellent are not definitive, but are Piedmont serpentine barrens together properly viewed as hypotheses subject to with consideration of the specific resource further testing and upgrading. How well potentials and constraints at the Unionville the ranges of target values reflect relative Barrens. quality under real‐world conditions may Metrics for populations of plant species be tested using data gathered in future of special conservation concern require years at the Unionville Barrens and at rough estimates of abundance and other serpentine barrens across the distribution of each extant species within Northern Piedmont as grassland the barrens. Target values are based on restoration and maintenance move crude estimation of the levels of forward. Hypothesis testing in this case abundance and patterns of distribution will be somewhat subjective and future required for long‐term population adjustments to target values based on viability, given what is known about each monitoring data will likewise rely to a species’ life history and other large degree upon professional judgment characteristics. and consensus among experts.

3.2 Threats A threat is a stress affecting a desired within the project area that can condition and the source or sources of that reasonably be expected within10 years stress. A stress is a process or event with under current circumstances if they do direct negative consequences on the not change? desired condition, such as forest • Irreversibility of damage—How succession at the grassland edge or responsive is the ecological attribute invasive species proliferation. A stressor described by the desired condition likely (source) is the action or entity that to be to corrective action after the produces a stress, such as fire exclusion or damage is done? soil organic matter accumulation. Threat analysis involves identifying and ranking The principal threats to the desired stresses and stressors for each of the conditions identified in the previous desired conditions. In ranking threats, section, in rank order of severity, scope several factors are taken into account: and irreversibility of the consequences, are: • Severity of damage—What level of damage can reasonably be expected (1) Critically low population numbers within 10 years under current associated with habitat area decline circumstances if they do not change? (2) Fire exclusion and forest succession • Scope of damage—What is the geographic (3) Invasive nonnative species scope of impact on the desired condition (4) Artificially elevated white‐tailed deer population 1 Analysis methods and results are detailed in Latham (2011). 61

3.2.1 Critically low population numbers Of the 27 plant species classified as associated with habitat area decline endangered, threatened or rare that have Nearly 90% of the 1937 grassland area been documented since around 1900 at the has been lost to forest succession (see Unionville Barrens, 9 were not found in Figure 2, p. 23). As the area of each 2004–2011 surveys and are probably gone grassland patch declines, the population (see Tables 1 and 6, pp. 22–23 and 37). It is numbers of all of the native plant and safe to assume that grassland‐dependent animal species that depend on grassland invertebrate species, which have never habitat also fall off. Wild plants and animals been comprehensively surveyed at the site, lack the option of responding to decreasing have declined at even higher rates, because living space by crowding together. The animal populations are generally more minimum amount of territory, food and sensitive and quicker to respond to habitat other land‐based resources each individual loss than plants. needs is a characteristic of its species. As As local habitat area declines for a numbers drop, any population becomes species, there is often an extended lag time more vulnerable to local extinction. Wild before extirpation, particularly for plants. populations fluctuate as a matter of course Plants may persist for years at less than the with year‐to‐year differences in weather, minimum viable population—what some predator abundance, disease outbreaks, ecologists have termed the “walking dead,” and other factors. When populations are that is, too few to have any significant small, their chances of dipping to zero ecological role, depleted in genetic diversity during normal fluctuation greatly increase. from inbreeding and thus increasingly Small, isolated populations are vulnerable to disease, and so highly especially vulnerable to disaster from localized that the last individuals are at risk causes such as disease, prolonged drought, of eradication by a chance mishap. With the or a management error based on steep loss of habitat area at the Unionville inadequate knowledge. An example is the Barrens since 1937, several species are heath hen (Tympanuchus cupido cupido), a likely living on borrowed time. Of the 18 wild cousin of the prairie chicken that once rare plant species known to survive at the lived in Pennsylvania’s serpentine barrens. site, at least 5 are represented by a Soon after European settlement of the precariously small number of individuals Northeast the species dwindled (Table 5, pp. 35–36). catastrophically due to hunting pressure. 3.2.2 Fire exclusion and forest succession By the early twentieth century, it survived only on Martha’s Vineyard, Massachusetts, With the major exception of salt where it was protected and considered to marshes along the Atlantic coast, most be secure. But, ironically, the decision by long‐persisting (dating from before wildlife managers to protect its habitat European settlement) native grasslands in from fire most likely sealed its fate. The the Mid‐Atlantic region owe their existence 1 dwindling of grasslands and heathlands on and long‐term maintenance to fire . This Martha’s Vineyard due to an absence of the principle has been recognized for a long fires that had sustained them for centuries time with respect to some grassland aggravated the population’s decline. When ecosystems, but apparently it was first the last individual on Martha’s Vineyard connected to serpentine grasslands in died, heath hens became extinct. particular less than 30 years ago2. The Extirpation—local extinction—of native species has already happened over the last 1 Day (1953); Thompson and Smith (1970); Denevan (1992); Latham and Thorne (2007) 50 to 100 years at the Unionville Barrens. 2 Miller (1981); Sladky (1981); Latham (1993)

peculiar qualities of serpentine soil were grassland even if fires occur seldom and thought to be enough to explain the sporadically. Most grasslands and meadows unusual vegetation until some botanists in the region would need to burn much and ecologists in the mid‐twentieth century more often and on a more regular schedule began to notice that the serpentine to prevent forest succession. grasslands were shrinking and The chief forest trees invading the disappearing. The losses were not all due to grassland edges are red maple, black‐gum conversion to housing developments and sassafras and black cherry. Black locust and golf courses; in many cases the culprit was ailanthus are nonnative weedy trees simple forest succession, starting at the invading small areas of the Unionville edges of the grasslands. Barrens. Black locust is native to parts of The reasons why succession seemed to eastern North America but did not occur abruptly begin taking its course in the mid‐ east of the Appalachians before European twentieth century after years of suspension contact; ailanthus is from northern and are twofold. First, increasing human eastern China. Common greenbrier is a population density in the area, together native woody vine that prefers wet habitats with advancing technology, led to effective or shade, but a greenbrier living in partial fire control in rural areas for the first time. shade and organic‐matter‐rich soils at the For the 2½ centuries before then, fires in forest edge or under an isolated tree can remote areas were allowed to burn send rhizomes into the open grassland and themselves out—rural residents had no grow a thicket there to harvest light rays, choice in the matter. Secondly, increasing secondarily shading out the grasses and human population density was forbs. Trees and greenbriers that accompanied by the abandonment of farms successfully invade grassland drop large and the end of livestock grazing. quantities of organic matter in dead leaves, Also critical to the connection between bark and branches. The buildup of soil fire and the persistence of serpentine organic matter eventually buffers plant life grasslands over long time periods are two in the vicinity against the effects of effects of severe soil conditions and harsh serpentine mineral soil, gradually summertime heat in the barrens—slowed converting barrens into species‐poor forest, which exterminates grassland species by plant growth and increased plant mortality. 1 The inhospitable conditions kill many trees shading them . at the seed or seedling stage and cause the 3.2.3 Invasive and aggressive plant few survivors to grow quite slowly, with species the exception of root‐suckering species such as black locust and sassafras (water Invasive nonnative species. The invasive and mineral‐nutrient needs of new shoots plant posing the greatest risk to serpentine originating as root sprouts are subsidized grasslands at the Unionville Barrens is via rhizomes, or underground runners, autumn‐olive (not to be confused with the connected to their full‐grown “parents” at closely related Russian‐olive, which is very the woods edge). The result is that grasses scarce at the Unionville Barrens, or with and forbs, which are more tolerant of thin any member of the unrelated true olive serpentine soils and hot conditions, can family, represented at the site only by white maintain their dominance longer between ash and border privet). In forest and tree‐killing disturbances in serpentine woodland and along forest edges, the barrens than in other kinds of grasslands, greatest threat is posed by autumn‐olive meadows and abandoned farm fields. This and stiltgrass. is why burning maintains serpentine 1 Barton and Wallenstein (1997); McCandless (1998) 63

Most of the nonnative species living in pounds of seed per year and the number of serpentine grassland occur there sparsely seeds per pound ranges from 20,000 to and are not considered a threat to the 54,0002, totaling 40,000–400,000 seeds per grasslands’ integrity. Examples in the plant per year. The seeds are distributed Unionville Barrens include common widely by birds and have a high rate of yarrow, field garlic, sweet vernalgrass, germination. Because seeds are bird‐ nodding thistle, Queen Anne’s‐lace, dispersed, commonly traveling hundreds of Deptford pink, sheep sorrel and meadow feet from the parent plant and occasionally fescue. To be considered as severely over much longer distances, it is helpful invasive, a plant species must usurp large wherever possible to eradicate autumn‐ amounts of space from native species and olive populations in larger areas cause changes in soil conditions that result surrounding the threatened area. in degradation of habitat for native species. Aggressive native species. The most So far only autumn‐olive meets these aggressive invaders of serpentine barrens criteria in the grassland. The list of invasive among native tree species are red maple species in the wooded parts of the barrens and eastern red‐cedar. Atypically, the is much longer. Besides stiltgrass and Unionville barrens lack the most prevalent autumn‐olive, which cover more area than aggressive native tree species at more than all other invasive species put together, the half of the Northern Piedmont serpentine most severe infestations are of garlic barrens—Virginia pine. mustard, Japanese barberry, Oriental bittersweet, Japanese honeysuckle, Amur Common greenbrier cover is moderate honeysuckle, multiflora rose and at the Unionville Barrens relative to many wineberry. Others present in small other serpentine barrens. Greenbriers are numbers but posing a risk of increasing most abundant in oak – red maple – impact include Norway maple, ailanthus, greenbrier serpentine forest and woodland black locust, winged euonymus and in the ecotone along the edge between (burningbush), border privet, Morrow’s that community and serpentine grassland. honeysuckle and tea viburnum. It is both fire‐tolerant and fire‐facilitating, as are the warm‐season perennial grasses Of all invasive plants, autumn‐olive is that dominate the savannas. Its highly the most severe threat to the ecological flammable stems and leaves spread fire integrity of the Unionville Barrens and to rapidly along the ground and, where there the imperiled species that live there. It has is a high density of climbing individuals, root nodules that house nitrogen‐fixing upward into tree crowns. It recovers 1. As a byproduct of gaining actinomycetes quickly post‐fire from reserves stored in nitrogen for themselves, autumn‐olives thick rhizomes. Greenbrier outcompetes increase its availability to other plants. herbaceous serpentine grassland plants in Where abundant, autumn‐olive can change situations of moderate shade, advancing as entire habitats by enabling nitrogen‐ a phalanx from the forest or woodland edge demanding plants to be highly competitive, or from beneath scattered savanna trees. replacing plants that are tolerant of soils with low available nitrogen (including all Fortunately, in experiments at the native serpentine grassland species), which Nottingham Barrens, prescribed burning tend to be poor competitors. across the grassland‐woodland edge has been found to result in the incremental Autumn‐olive produces a large amount of seed. A single individual can produce 2–8

2 Sather and Eckardt (1987) citing Holtz (1981) but 1 Sather and Eckardt (1987) without listing the source

retreat of greenbrier advancing fronts1. continued to regulate deer populations Greenbrier can also be effectively curtailed until Europeans arrived and expelled all by mechanical removal and off‐site disposal three. of the top few inches of soil, including the Recreational hunting as it is practiced greenbrier rhizomes. today under strict game laws and for only a 3.2.4 Artificially elevated white‐tailed short interval in the fall and winter has deer population traditionally had relatively little impact on deer population numbers, although NLT’s White‐tailed deer are a natural part of deer management program has achieved the region’s ecosystems, but a convergence some success by recruiting and supervising of events has caused them to proliferate to hunters and focusing their efforts on doe unprecedented population densities. For removal. Success in limiting deer the first two centuries after Europeans populations to levels compatible with arrived the human population grew restoring and sustaining ecosystem exponentially and unlimited hunting integrity also hinges on cooperation by eroded the balance between predators and neighboring landowners. Deer pass freely deer that had prevailed for eons. By 1900 across land ownership boundaries except deer were nearly extinct in Pennsylvania where predator (hunting) pressure is and other eastern states because of over‐ different on one side of the line from the harvesting. By then the native predators of other. Areas where hunting effort is low or deer had been exterminated. State agencies nonexistent serve as refuges and can instituted game laws in an effort to rebuild sabotage even the best deer management the deer population. These hunting rules, program on adjacent lands. which have persisted to the present with few major changes, focused on providing a Deer thrive best in the forest‐edge maximum sustained yield of game for habitat that timbering, farming and recreational hunters. Deer reproduce suburbanization have created over most of rapidly and the deer population soared to our region. The unprecedented high unprecedented levels in just a few decades. numbers that exist in much of the region today consume the tree seedlings and Deer populations are no longer kept at saplings, shrubs and wildflowers that in ecologically innocuous levels as they were more favorable circumstances make native for more than 99% of their existence—for forest and grassland ecosystems healthy, over two million years by large predators beneficial to other wildlife and self‐ and for most of the last 13,000–15,000 sustaining. Much of the forest in and years or longer also by Native Americans, around the Unionville Barrens has been for whom venison was a major source of stripped of native understory vegetation. food. A diverse array of predators regulated The dense layer of native shrubs, young deer populations for millions of years trees, ferns and wildflowers that are the before humans arrived in what is now hallmark of a healthy forest is sparse or, in southeastern Pennsylvania, including the some parts, almost completely missing. The gray wolf, dire wolf, grizzly bear, giant understory now is typically either largely short‐faced bear, mountain lion, American devoid of plant life or choked with invasive cheetah and jaguar. When human hunters nonnative species, especially autumn‐olive, arrived they displaced all but a handful of stiltgrass, Oriental bittersweet, multiflora the other major predators, but American rose and garlic mustard. Deer and other Indians, gray wolves and mountain lions plant‐eating wildlife generally avoid invasive nonnative plants, which is one of 1 Latham and Thorne (1997); R. E. Latham, unpublished the reasons they can proliferate unchecked. data 65

The effects of deer on grassland are whether observed ecosystem trends are much more subtle than in the forest. The due to deer or to other factors, and dominant grassland plants are adapted to determine when adjustments to deer disturbance, including grazing and management methods are needed to browsing. The few pertinent scientific achieve or sustain desired conditions. studies have shown a positive influence on However, devising an effective set of Midwestern prairie forb diversity at very metrics is complicated by the need to low deer density and negative effects at separate deer effects from the multitude of densities similar to those prevailing today other influences on vegetation and by the in southeastern Pennsylvania1. Species that fact that deer feeding preferences are are highly preferred by deer have little notoriously variable from place to place chance against the onslaught of the current and at different times. deer population, which may be 20 times Food preferences depend partly on what is higher than before European settlement. available to eat. Food variety and availability Plants known to be vulnerable include in turn depend on current local deer density, many current residents of the Unionville recent trends in local deer density, availability Barrens whose regeneration has been of alternative forage, human land‐use halted or nearly so, including the seedlings patterns, forest disturbance history, snow and small saplings of the eight oak species cover, and various other factors. Thus, found at the site. Oaks may appear secure preferred species frequently differ between to the casual observer but when the current regions in the same forest type, within regions over long periods of time, at different adult trees die through natural decline, times during a growing season, and at disease or windfall, the populations will different deer densities in the same forest decline or disappear if high rates of deer type.2 browsing persist. Several other vulnerable plant species have already been extirpated Separating deer effects from other from the Unionville Barrens, including influences requires that indicators be colic‐root and downy lobelia (both measured using exactly the same methods endangered in Pennsylvania) and lion’s‐ inside and outside of fenced deer foot and white heath aster (both threatened exclosures (see Monitoring deer effects, p. in the state), but it is only a guess whether 83, and Experimental control, pp. 149–150). and to what degree the outsized deer The unpredictability of feeding preferences population was a factor in their demise. is sidestepped as a potential confounding factor in the same way, by comparing Sustaining or restoring any of these vegetation change over time between species must start with the goal of reducing adjacent fenced and unfenced monitoring and maintaining deer density at an quadrats. Indicators related to deer appropriate level. Unless that goal is herbivory include: achieved, management of other stressors • relative frequencies and abundances of and attempts at reintroduction will be a plants preferred and avoided by deer as lesson in futility that ultimately will end food with the loss of more vulnerable species. • survival and fecundity of plant species Monitoring well‐chosen indicators is the known to be exceptionally highly only sure way to track success in ongoing preferred management of the deer population, verify

1 Anderson et al. (2001, 2005) 2 Latham et al. (2005): p. 51

Management Recommendations

4.1 Adaptive management Adaptive management, in is applied? Why is it necessary to conduct simplest terms, consists of trials in more than one area at the same 4 carrying out a set of actions, time? And why go to the trouble of actually periodically monitoring the measuring and quantifying the results? Isn’t results, reconsidering the methods in light it enough to just look at what happens in of those results, and adjusting the next order to judge whether a method works round of implementation accordingly. This well enough to keep on using it? approach is a way of reducing uncertainty Throughout this section, a distinction is without high‐cost research. Trials of made between restoration and maintenance promising alternative methods for phases of management. Restoration is achieving objectives are carried out and aimed at changing ecosystem attributes results compared quantitatively as a part of now considered “poor” or “fair” toward routine management. This subsection their desired condition, preferably in a outlines stewardship tools and methods short span of years. Maintenance is aimed needed to achieve and sustain desired at keeping those ecosystem attributes conditions. Monitoring, an indispensible within the “good” to “excellent” range over part of adaptive management, is covered in the long term—in fact, indefinitely. subsection 4.2 (pp. 80–84). The concluding Restoration work is generally more time‐ subsection (pp. 84–91) prioritizes tasks and energy‐intensive and more costly on an and outlines a timetable. The fundamentals annual basis than maintenance work. of effective design of management trials are given in Appendix D (pp. 149–153). For convenience in planning and communication, the barrens are divided Skepticism about adaptive management into seven numbered management units or arises from fears that it will be too time‐ M.U.s (Map 10). Each M.U., in turn, is consuming or add costs, burdening divided into grassland management areas stewardship budgets already stretched (shown in yellow on Map 10 and labeled as thin. However, part of the motivation to the grassland restoration target area) and adopt adaptive management is to save time forest management areas (untinted on Map and money in the long run. It is more 10). Besides grassland and forest, a third powerfully self‐correcting than traditional category of vegetation is woodland, defined management approaches, discarding as having 25%–60% tree cover across methods with second‐rate performance minimum mapping units of 1 acre. Wood‐ more quickly (saving time that would lands will—as restoration progresses—lie otherwise be wasted) and improving mostly along the edges where grassland methods faster toward greater effective‐ and forest management areas meet. ness and efficiency. Appendix D, if read in Woodlands may fall either in the grassland conjunction with this section, attempts to or forest management areas on the map but answer a skeptic’s questions: When they can be differentiated from forest, confronted with a management problem, which is defined as having 60%–100% tree why not just try something and see if it cover, by visual appraisal on the ground. works? What is the point of comparing the results of alternative methods with each The grassland management areas are other or with areas where no management further divided into two zones—present‐

day grassland (yellow area on Map 4) and Tree removal in grassland management forest and woodland to be restored to areas (shaded in yellow on Map 10) will grassland (overlap between the two shades target most trees, but some species are of green on Map 4 and yellow on Map 10). excluded from cutting. Future (post‐restoration) grasslands will be Trees off‐limits to cutting in grassland a mosaic of savanna, defined as having management areas include oaks of species 10%–25% tree cover, and prairie, with 0%– that are part of the characteristic flora of 10% tree cover in a contiguous area (single Northern Piedmont serpentine barrens, GIS polygon) that can fully enclose a circle open‐grown oaks with branches almost of at least 1 acre (≥ 236 feet in diameter). down to ground level (emblematic of the The seven M.U.s cover all the barrens savanna landscape), and very large oaks. area regardless of present ownership. M.U.s They are: 1–5 lie mostly within present ChesLen • any post oak, blackjack oak, Bush’s oak Preserve boundaries. M.U.s 1, 2 and 5 will (blackjack oak‐black oak hybrid), water grow larger (see interim boundaries, Map oak or dwarf chinkapin oak 10) and M.U.s 6 and 7 will be added if NLT • isolated open‐grown trees in existing gains management rights on the two grassland of black oak, scarlet oak, neighboring parcels. northern red oak, pin oak, white oak or 4.1.1 Selective tree removal and chestnut oak replacement • large specimen trees ≥ 20 inches dbh Restoration of grassland on over 50 (diameter at 4½ feet above the ground) acres of forest and woodland that had of any oak species grassland cover within the last 75 years Eastern red‐cedars also should be left starts with substantial, but still somewhat standing for the most part to serve as long‐ selective, tree removal. In the grassland lasting snags providing habitat for cavity‐ restoration target area, the main objectives nesters (see Treatment of eastern red‐cedar, of tree removal are greatly increasing next page. If workers cutting other trees sunlight at ground level and eliminating the would have to go to unusual lengths to main source of soil organic matter avoid felling a particular red‐cedar, it may accumulation. A moderate level of more be cut. highly selective tree removal is desirable in The reasons to preserve very large oak the forest management areas. The objective trees are as much esthetic as biological. there is to counter the successional They are major sources of food and trajectory toward replacement of the oak complex tree‐canopy habitat for wildlife canopy by red maple and other mesic forest and of acorns endowed with good survival trees that began with fire exclusion in the genes to perpetuate oak regeneration. But mid‐twentieth century and accelerated they also have historical significance and with the onset of seedling overbrowsing by are a source of awe and inspiration. It is the outsized deer population. inappropriate to take down monumental The most cost‐effective and least oaks in a nature preserve. The threshold environmentally damaging method of tree size of 20 inches dbh is high enough that a removal is cutting flush to the ground and relatively small number of the largest trees hauling away the entire tree to be used for will be preserved. a purpose that prevents the carbon bound Tree thinning in forest management in the wood from being released as CO2 for areas (areas within management units but a significant period of time. Certain species not shaded in yellow on Map 10) will be must be removed by other means. more limited, with a broader range of trees

excluded from cutting. The objectives of white oak, pignut hickory, northern red oak thinning are to (on lower slopes only) and chestnut oak • enhance tree size variation and (on upper slopes and the ridgetop only). structural diversity in even‐age stands Since the barrens are an important • open up the canopy to increase sunlight natural area, introduction of non‐local at the forest floor and favor tree seedling genotypes should be avoided. Ideally the and sapling growth, especially of oaks planting stock should be raised from acorns and hickories and hickory nuts collected at the site. But if The objective of tree thinning in forest the stock is needed earlier, container stock management areas is to redirect forest from Pennsylvania Northern Piedmont succession back into a pathway toward genotypes can be bought from a reputable mixed oak dominance and away from its native plant wholesale nursery. It is best if current trajectory toward red maple they come from seed collected in Chester dominance. Oaks are poorly represented in County or its neighboring counties. the < 6 inches dbh cohort of trees to be left Large seed trees of oaks and hickories behind in a wood products harvest, which should be left intact at a high enough will take most trees 6–20 inches dbh. In density for mice and squirrels to spread two approximately 25‐m × 25‐m quadrats seed throughout the area, in anticipation of in M.U.s 1 and 2 surveyed informally in the time when deer density is brought 2011, oaks and hickories made up down to a level that allows natural oak • 12% of trees < 6 inches dbh regeneration and is maintained at that level • 19% of trees 6–20 inches dbh long‐term. • 100% of trees > 20 inches dbh Tree species to be generally excluded from cutting in forest management areas: Those percentages for red maple and black‐ gum were • sapling (< 6 inches dbh) and large (> 20 • 68% of trees < 6 inches dbh inches dbh) oaks, pignut hickory (and other hickory species, if found) and black • 74% of trees 6–20 inches dbh walnut • 0% of trees > 20 inches dbh • a few intermediate‐size (6–20 inches Sustaining or restoring oak dominance dbh) oaks and hickories per acre of any in these stands requires that stewardship species not represented in the large size staff (and volunteers) go into those areas class, to serve as additional seed sources after the intermediate‐sized trees are cut to • eastern red‐cedar (to be converted to thin the smaller trees. Any sapling oaks and dead snags and, where stands are very hickories should be left intact. Red maple, dense, thinned; see next page) black‐gum, tuliptree and other native mesic • ailanthus (removed by other means) forest species should be drastically thinned. Nonnative species should be eradicated. • black locust (removed or converted to Thinning will improve the prospects for oak dead snags by other means) regeneration over what they are now in The latter three species are singled out every way except one—there are still too for special treatment other than cutting. many deer to allow regeneration from seed. Ailanthus and black locust should not be After at least one post‐thinning burn to cut or girdled because such actions reduce invasive species abundance, oaks typically result in massive proliferation of and hickories will need to be planted in tree root suckers. These two species are tubes in the larger canopy gaps. The species discussed below under Invasive and to be planted are black oak, scarlet oak, aggressive species control (pp. 74–78).

Tree species targeted for cutting in forest shade and continually shed old leaves, management areas: which loads decomposing organic matter • natives (objective is drastic thinning but onto the soil. Both effects foster invasion by not eradication): non‐barrens species, especially invasive ° red maple nonnatives such as stiltgrass, Japanese ° black‐gum honeysuckle, Oriental bittersweet and ° tuliptree (yellow‐poplar) garlic mustard. As dead snags, they are ° white ash exemplary habitats for cavity‐nesters and ° black cherry other snag‐utilizing wildlife because their ° American beech wood is rot‐resistant and they can provide ° bigtooth aspen many years of service. Local cavity‐nesters ° sassafras include flying squirrel, wood duck, screech • nonnatives (objective is eradication): owl, barred owl, barn owl, American kestrel, downy woodpecker, hairy ° white mulberry crabapple woodpecker, red‐bellied woodpecker, ° northern flicker, pileated woodpecker, red‐ ° sweet cherry common pear headed woodpecker, tree swallow, eastern ° phoebe, great crested flycatcher, purple ° Norway maple sycamore maple martin, white‐breasted nuthatch, gray ° catbird, Carolina wren, house wren, eastern Preventing stump‐sprouting. Herbicide bluebird, black‐capped chickadee, Carolina may be applied to the freshly cut stumps of chickadee, tufted titmouse and nonnative stump‐sprouting species, in prothonotary warbler. Hawks and owls use particular Norway maple, sycamore maple dead snags as perches. After trees or snags and white mulberry. Such treatment is not fall, the logs and branches provide essential necessary for native species because for habitat for a wide variety of amphibians, them the objective is not eradication; for snakes, mammals and arthropods. oaks in particular, stump‐sprouting is a desired condition. Glyphosate without an Conversion of red‐cedars to dead snags. added surfactant (trade names Rodeo, Most of the eastern red‐cedars at the Accord) is the least environmentally Unionville Barrens should be left standing damaging choice for treating freshly cut but converted to dead snags. Some will be stumps of nonnatives (other than ailanthus killed (but not destroyed) the first time and black locust; see p. 76). It is effective they are exposed to prescribed fire, either when applied to the outer 2–3 inches of a by torching—fire igniting the resinous, stump’s rim within a few minutes of highly flammable foliage of a red‐cedar’s cutting. crown—or by injury to the bark’s inner cambium at the base of the tree if the No cutting in wetlands. Black‐gum and red ground fire is exceptionally hot. Torching is maple dominance is a desired condition in possible if ground fuels support flame the swamps along Corundum Run (see Map lengths higher than the lowest foliage, 8). Cutting, skidding and equipment likely only where dense grasses or shrubs transport should be kept out of any wet surround a red‐cedar with intact low ground and a reasonable buffer (at least 50 branches or where there are ladder fuels— feet) around it. dense vines such as greenbriers climbing Treatment of eastern red‐cedars. Eastern into the crown. During a prescribed burn, red‐cedar is a characteristic species of the isolated red‐cedars in grassland that escape serpentine barrens but can displace burning can be ignited by applying a drip grasslands if allowed to proliferate in the torch or a flamethrower designed for use in absence of fire. Live red‐cedars cast dense prescribed burning (trade name Terra

Torch) to individual trees. After an area has proliferation of undesired species. The been burned once or twice, most of the red‐ response of invasive species will vary from cedars that remain alive may be converted one area to another within the barrens. It is into dead snags by basal bark application of expected to be most severe where forest triclopyr (trade name Garlon 4) mixed with stands are thinned to a very open‐canopy a penetrant or in a ready‐mixed state and least severe where the trees that formulation (Pathfinder II). Waiting to see are removed have warm‐season grasses how many trees are killed by fire cuts down growing beneath them before removal. It is time and material costs for herbiciding and worth looking ahead to the various likely reduces herbicide collateral damage to outcomes of taking the trees out all at one nearby plants, including rare species. time over a large area to ensure that Thinning of dense stands of red‐cedar. In stewardship staff is prepared to deal with the densest red‐cedar stands, which occur them. Funding, equipment, supplies and in M.U. 3 and the northwestern corner of personnel time should be secure for any M.U. 2, the density may be reduced by and all probable outcomes. Likely scenarios include, but are not limited to: thinning—flush‐cutting selected trees to ground level or pulling them out of the • Best case—a mixture of invasives and ground whole with a backhoe. Sawn trees barrens natives develops and there is should be removed from the site but pulled enough fuel for a hot burn the following trees, because they resemble natural spring or summer, which greatly reduces treefalls and are similarly beneficial to the invasive cover relative to the native wildlife, may be left on the ground in small cover. numbers. In general, larger trees should be • Worst case—mostly invasives develop left standing for conversion to snags and it rains too much for any burning the because they can support more cavity‐ following year, allowing them to become nesting wildlife. Trees selected for felling fully established and produce a large should be mainly in the small to inter‐ seed crop in the first season. mediate size range. Very large red‐cedars, • Intermediate case 1—the fuel still is not 18 inches trunk diameter or larger, may be dense enough in the first 1–2 years to left intact and alive as specimen trees. carry a fire across the entire timber cut, Selected red‐cedar trees to remain alive. which allows the invasives to become A few smaller red‐cedars should be left fully established and set seed, but intact and alive. A reasonable target density prescribed burns starting in year 2 or 3 for live trees is 1–10 per acre, which can be post‐fire gradually reduce their cover. achieved by killing 90%–95% of the red‐ • Intermediate case 2—a drought pre‐ cedar population living in the barrens in cludes burning the year after cutting, but 2010 (shown in red on Map 4). The very the drought itself reduces the invasive largest trees have special esthetic and cover relative to the native cover. historical value and should be allowed to Control of invasive and aggressive reach the end of their lifespan by natural species is the subject of subsection 4.1.3 causes. (pp. 74–78). Expected outcomes of tree removal. In terms of staff time, logistics and funding, 4.1.2 Prescribed burning the most practical approach to tree removal Frequency and severity of prescribed is contracting with a wood products burning. business to harvest trees over large areas all at once. There is a high risk that large‐ Prescribed burning in grassland is to be scale tree removal will result in massive applied as often as needed to halt the

spread of woody plants, especially common Canada thistle, garlic mustard and mile‐a‐ greenbrier, that overrun and displace minute. Later, in the maintenance phase, herbaceous plants. Fire return intervals can the objective is to restore oak regeneration be as short as 2–3 years early on in the by releasing oak seedlings and stump restoration phase and later, 10–15 years or sprouts from suppression by faster‐ longer for maintenance. No attempt should growing but less fire‐tolerant tree be made to standardize return interval. seedlings, saplings and stump sprouts such Decisions about what year to burn should as those of red maple, black‐gum, tuliptree, be triggered by local conditions, for white ash and black cherry. The trigger for instance, by an established grassland area maintenance burning is a dense growth of having passed a threshold level of tree or tree seedlings and saplings, including oaks. greenbrier invasion. The desired condition This in turn depends critically on light of high grassland patch diversity can be availability (canopy openness) and fostered by varying the fire return interval intensity of winter deer browsing. among and within patches over long Low‐severity fires will achieve the periods of time, much as it would have forest management objectives of helping to varied throughout the ecological history of restore oak and hickory regeneration, the temperate eastern North American redirecting forest succession back toward serpentine barrens throughout their range. mixed oak dominance and away from red Grassland burns are typically low‐ maple dominance in the canopy, and severity, but high‐severity (overnight discouraging understory dominance by smoldering) fire is desirable in certain nonnative invasive species. High‐severity circumstances, including where cover of fires would pose a risk of killing the native common greenbrier is higher than 20% or trees and understory plants that define the where high soil organic matter accumula‐ forest ecosystem and giving advantage to tion persistently supports the proliferation nonnative invasive species that thrive in of nonnative plants or rapid growth of the typically deep forest soils with native or nonnative woody vines. Mitigating increased light. the increased risk of escape associated with Prescribed burning in open woodland high‐severity fire involves applying it in a between grassland and forest may need to small area at any one time—small enough be more frequent, more severe, or both to for one person to be able to see the entire achieve desired conditions than in either burn unit post‐fire from one vantage open grassland or closed‐canopy forest. point—and maintaining round‐the‐clock The rationale for this hypothesis: monitoring until the fire is extinguished. (1) Soils are thicker there than in open Prescribed burning in forest needs to be grassland, supporting invasion by non‐ applied less frequently than in grassland. barrens species. Forest areas may be burned concurrently (2) Partial shade at ground level allows with adjacent grasslands as large, combined growth of non‐grassland species that units. Early on, in the restoration phase, the are intolerant of extreme summer heat main objective is to reduce or eliminate in open grasslands. invasive woody species such as Oriental bittersweet, Japanese honeysuckle, Japan‐ (3) Common greenbrier reaches its densest ese barberry, winged euonymus, Amur growth in the ecotone and experimental honeysuckle, wineberry and multiflora rose ecotonal burning has decreased its (but not autumn‐olive) and to reduce seed cover there. production and survival by invasive The desired condition of open woodland annuals and biennials such as stiltgrass, is an understory dominated, at least in

patches, by native warm‐ and cool‐season grasslands has been in spring before most grasses. Whether this condition can be plants have leafed out. Growing‐season achieved by burning only at the same time (late summer) burns should be subject to as adjacent grassland or if it will require repeated trials in different areas to assess additional, smaller burns focused their effectiveness in meeting desired specifically on woodland is unknown. The condition objectives. In all likelihood, there adaptive management approach provides was considerable variation in seasonality of the framework for resolving such fire through the evolutionary history of questions—conducting trials of alternative serpentine grasslands. It is reasonable to methods in several replicate plots, in this expect that spring burns will work best to case, varying fire frequency and severity, meet some objectives, growing‐season then measuring and comparing the effects burns will work best to meet others, and of high and low frequency and high and low conducting both kinds of burns in different severity on key indicators. parts of the barrens in different years will Scale of prescribed burning. No more result in higher patch diversity and native than one‐third of the existing grassland species diversity across the entire habitat should ever be burned in one year landscape. Spring burns generally favor at any site where species of special conser‐ warm‐season grasses and late‐flowering forbs over cool‐season grasses, graminoids vation concern are present1. This is because some of the rare species are insects, many and early‐flowering forbs, whereas late‐ of which are killed outright by fire. Further‐ summer burns are likely to have the more, recolonization of burned areas by opposite effect. insects is not instantaneous. It can take 1–5 After tree cutting, parts of the grassland years for insect populations to recover restoration area with deep soils, especially following a burn2, even if the burned area is on mid‐ to lower slopes, are expected first adjacent to occupied habitat that is not to support a rapid growth of woody plants burned that year. and nonnative invasive plants and Burn units correspond roughly but not eventually, with repeated or severe fire, to fully to the seven management units develop dense, relatively uniform stands of (M.U.s). Some prescribed burns will tall warm‐season grasses. Such stands often comprise an entire management unit (or exhibit high dominance (low species more than one), covering forest, woodland evenness) and low species richness. and grassland in the same fire. However, it Occasional late‐summer burns in such is not necessary or desirable to burn oak situations may enhance both components forest areas as often as the adjacent of species diversity. Adaptive management woodland and grassland areas, so some trials are the most powerful tool for testing burns will be confined to just the grassland this prediction. and woodland parts of a management unit. 4.1.3 Invasive and aggressive species Furthermore, varying fire footprints over control years and decades to achieve desired patch diversity and diversity of habitats requires On thin serpentine soils with little shade that prescribed burns should sometimes from trees, invasive plants pose little threat target partial or multiple M.U.s. to native serpentine barrens biodiversity. Typically an initial flush of undesired Season of prescribed burning. Almost all species appears after disturbances such as burning to date to manage serpentine tree‐cutting or mechanical removal of the upper layer of soil, but most disappear in 1 Schultz and Crone (1998) 1–3 years, or more quickly if the 2 Swengel (1996); Panzer (2002) disturbance is followed by prescribed 73

burning as soon as growth produces seeds in the soil seed bank to break enough fuel to carry a fire. However, the dormancy. The increased sunlight at thicker the soil, the more buffered from the ground level after canopy thinning or serpentine soil syndrome newly removal will enable rapid growth. A burst germinated plants will be, and the faster of plant‐available nutrients released by and more closely packed the undesired increased decomposition of organic matter species are likely to grow. Moderate shade residues by soil microbes will give invasive in woodland and savanna, in contrast with nonnative species a strong advantage over full sun in treeless areas, also is likely to native barrens species. facilitate invasion by undesired species. In newly restored grassland, prescribed Ranked in terms of severity of burning within a year after tree clearing infestation and urgency of treatment, the and repeated at least once or twice within most important invasive nonnative species the following 2–4 years is expected to be are autumn‐olive1 and stiltgrass2. Other effective in controlling invasive species. woody species degrading ecosystem Desired conditions may be achieved sooner integrity are ailanthus3, Japanese barberry4, by supplementing burning with spot‐ Oriental bittersweet5, winged euonymus6, herbiciding localized outbreaks of prolific Japanese honeysuckle7, Amur honeysuckle8, seed‐dispersers such as Canada thistle, if multiflora rose9, black locust10 and stands are not too large or numerous. wineberry11. Other herbaceous species Persistent problem spots are also likely posing major threats are garlic mustard12, where soils are thick or high in organic Canada thistle13, lesser celandine14 and matter, for instance, in depressions where mile‐a‐minute15 (for online information dead leaves collect or on concave slopes sources on these species see Appendix E, where soil builds up with sheet erosion. In pp. 154–157). such cases, consideration should be given Invasive species infestation is expected to physically removing the invasive plants, to undergo a temporary upsurge in areas including their roots, together with a few where trees are removed. Soil scarification inches of the organic‐matter rich upper soil by equipment and dragged trees will cause layer using a front‐end loader or backhoe and disposing of the material off‐site.

1 Sather and Eckardt. (1987); Munger (2003) Removing autumn‐olive. The highest 2 Barden (1991); Tu (2000); Swearingen and Sheherezade urgency is placed on autumn‐olive removal. (2008); Flory and Lewis (2009); Fryer (2011b) Initially, this will consist of trials of two 3 Hoshovsky (1988); Swearingen and Pannill (2009); methods on four trial plots (Figure 5): Fryer (2010) (1) mechanical removal of entire plants 4 Swearingen (2005); Zouhar (2008) using the tines of a backhoe bucket, with 5 Dreyer (1994); Swearingen (2006); Fryer (2011a) off‐site disposal; (2) basal bark application 6 Martin (2000); Fryer (2009) 7 Nuzzo (1997b); Munger (2002a); Bravo (2005) of triclopyr (trade name Garlon 4) mixed 8 Batcher and Stiles (2000); Munger (2005); Williams with a penetrant or in a ready‐mixed (2005) formulation (Pathfinder II), with later 9 Eckardt (1987); Munger (2002b); Bergmann and burning of dead aboveground parts in the Swearingen (2005); Bowles et al. (2007) course of prescribed burning. Use of foliar 10 Converse (1984); Wieseler (2005); Stone (2009) herbicide is not recommended in the 11 Spencer (2005); Innes (2009) Unionville Barrens for autumn‐olive control 12 Nuzzo (2000); Munger (2001); Rowe and Swearingen (2005); Bowles et al. (2007) because damage to nearby nontarget 13 Nuzzo (1997a); Zouhar (2001); Thunhorst and species is unavoidable when spraying the Swearingen (2005) foliage of large shrubs and because of the 14 Swearingen (2010) large scope of the infestation. 15 Gerlach et al. (2010); Stone (2010)

These trials are an example of adaptive management. The result will be achieving a crucial management objective across the entire trial plot area but the added step of comparing quantitative indicators between two methods will allow stewardship staff to learn some valuable lessons that can be applied to other infested areas within the barrens (and elsewhere in NLT’s preserve system). The largest areas of autumn‐olive infestation at the Unionville Barrens besides M.U. 1 are in large parts of M.U.s 3 and 6, but there are scattered autumn‐olive stands in every Figure 5. Autumn‐olive removal trial plots. Two management unit. approaches—mechanical removal and basal‐bark herbicide Among the hypotheses or treatment—are recommended to be compared in terms of predictions to be tested in the effectiveness, staff time and material costs in four trial plots trial plots are: in Management Unit 1 (see Maps 4 and 10 for landscape context of trial plot area). The results may show one (1) Mechanical pulling will method as superior overall or they may show both to be disturb soil, increasing useful for removing autumn‐olive elsewhere in the barrens, erosion of upper soil layers with the better method for a specific area depending on (desired) and stimulating local conditions. This is a model for many more adaptive germination of invasive management trials to come, which will be devised by plant seeds in large numbers stewardship staff and their scientific advisers based on (undesired). It is unknown future management challenges, future changes in what the balance will be conditions, or new management methods and technologies. between these effects. (2) Mechanical pulling and off‐site disposal first three pages of Table 7 (pp. 50–52), will remove some of the nitrogen miner‐ namely trends in the cover of nonnative alized by symbiotic bacteria in autumn‐ plant species, autumn‐olive survival rates, olive roots (desired) whereas basal bark and trends in the cover of characteristic herbicide application followed by serpentine grassland plant species. An burning or decomposition of dead additional set of indicators is estimated autumn‐olive biomass will return staff time, material and equipment costs excess nitrogen and other nutrients per acre for each of the four trial plots. One bound in biomass to the soil where it 25‐m × 25‐m quadrat may be used to assess will favor invasive species (undesired). the autumn‐olive survival rate near the center of each trial plot and four smaller (3) Basal bark herbicide application may be quadrats, each 2 m × 2 m, randomly located cheaper per acre in staff, material and within each larger quadrat to track changes equipment costs. in nonnative and characteristic serpentine Metrics for evaluating these hypotheses grassland species cover (see details on include some of the ecosystem response methods under Monitoring, pp. 80–84, and and desired condition metrics given in the Randomization, pp. 148–149). Quadrats for 75

these trials can be regarded as temporary after it has apparently been eradicated. and monitored for just a few years. It is Follow‐up monitoring is essential. likely that one or more of the recommend‐ Reducing common greenbrier density. ed 5‐m × 5‐m permanent monitoring Common greenbrier is fully fire‐tolerant quadrats will also be placed within the trial and is not reduced by burning in a area. If a permanent monitoring quadrat woodland or forest edge situation with should be situated near the center of any of partial shade. Herbiciding using a foliar the four trial plots, it can do double‐duty spray of glyphosate gave poor results in and replace two of the smaller species experimental trials at the Nottingham cover quadrats. Barrens; the vines were killed but not Eradicating ailanthus and black locust. replaced by other species and greenbrier Ailanthus (tree‐of‐heaven), from northern cover was restored in just a few years. In and eastern China, and black locust, with a other Nottingham Barrens experiments, native range from central Pennsylvania to “ecotonal burning”—driving prescribed fire Oklahoma and Alabama, spread prolifically across the forest‐grassland edge—caused in grasslands and harm grassland plants by greenbrier to retreat and native warm‐ shading them and by changing soil season grassed to advance. Repeated conditions. Ailanthus secretes allelopathic ecotonal burning can expand grassland and chemicals that deter establishment of other reduce dense greenbrier thickets plants1 and black locust houses symbiotic incrementally over long periods. However, bacteria in root nodules that convert inert this incremental approach may be effective atmospheric nitrogen to forms that enrich only in full sun and where soils are thin. the soil in mineralized forms of nitrogen Greenbrier thickets are more tenacious available to plants. where soils are thicker and in the partial Both species are rhizomatous, that is, shade of savanna or woodland trees or they spread by underground runners. along the southern edge of a grassland (Sassafras is also rhizomatous, but it is patch, where shade cast by adjoining forest locally indigenous and less aggressive in is deepest. In such conditions, a more serpentine barrens than the other two.) effective way to reduce greenbrier cover is Burning, cutting, girdling or even injuring by partial soil organic matter removal. the stems of these trees stimulates rapid Partial soil organic matter removal with proliferation of new suckers by breaking off‐site disposal. Removing the roots and the dormancy of underground buds along top few inches of organic‐matter‐rich soil their rhizomes. Painting herbicide on cut or from areas dominated by undesired woody girdled stumps does not prevent plants such as autumn‐olive, black locust, suckering2. The most effective and efficient ailanthus or common greenbrier has way of eradicating them is to leave the proven effective as a way of restoring trunks intact and employ a basal bark serpentine grassland and serpentine gravel application of triclopyr (trade name Garlon forb communities. The first experiments 4) mixed with a penetrant or in a ready‐ were conducted in the mid‐1990s at the mixed formulation (trade name Pathfinder Nottingham Barrens. The results were so II). This method has proven its reliability in favorable that the method has been applied many trials across the country but as a restoration tool at several other nevertheless black locust in particular is serpentine barrens, including Goat Hill, known for resprouting, sometimes years Rock Springs Barrens and Pink Hill. The typical result has been immediate coloniza‐ tion of the treated area by a diverse array of 1 Hoshovsky (1988); Swearingen and Pannill (2009) 2 Converse (1984); Swearingen and Pannill (2009) the characteristic species of serpentine

grassland and gravel forb communities. Reducing stiltgrass cover in forest/ There is often a minor admixture of woodland stands. There is little informa‐ invasive nonnative plants and other non‐ tion available on the effects of prescribed barrens plants in the first growing season, burning on the locally important invasive but most die within a year or two. species of forest and woodland, including 1 The method works by reducing the stiltgrass . Spring burns are ineffective at blanket of organic matter that buffers many controlling stiltgrass because a new cohort non‐barrens plant species from the low of seeds germinates quickly post‐fire. There calcium‐to‐magnesium ratio and high is some evidence that burns in late summer or fall may be useful in controlling the nickel content (serpentine soil syndrome) 2 of the underlying mineral soil. Presumably species but annual burning in oak forest actually resulted in increases in garlic it also exposes a rich seedbank of 3 characteristic serpentine barrens species; mustard , a biennial whose response to fire however, most of the successful applica‐ may or may not be similar to that of tions of the method have been on ground stiltgrass. Running trials is the only way to that was very near an existing area of determine how stiltgrass and other serpentine grassland and serpentine gravel invasive forest‐floor species will respond to forb vegetation to serve as an ongoing seed fire under the particular conditions of source. Seeding after partial soil removal Unionville Barrens forests and woodlands. using seed collected on‐site could be used In Big Oaks National Wildlife Refuge, Indiana, in areas not immediately adjacent to an late summer prescribed fire, spring prescribed existing grassland. fire, hand‐pulling, and fall mowing were compared as control treatments for Japanese Per‐acre costs have not been tallied but stiltgrass. Study sites were in second‐growth they are high compared with other American beech – black walnut – Virginia restoration methods, in addition to posing pine/northern spicebush forest with a history of unusual logistical challenges such as prescribed fire. Late summer fires were ignited transporting and appropriately disposing of and mowing was conducted in early September soil contaminated with invasive or after Japanese stiltgrass had set seed. Spring aggressive plant roots and seeds. Areas so fires were ignited and hand‐pulling started in treated also must be accessible by heavy June, when Japanese stiltgrass seedlings were 4 machinery, including a backhoe or front‐ to 8 inches (10–20 cm) tall. Compared to untreated control plots, fall fire and mowing end loader and dump truck, without caused significant reductions in Japanese harming existing stands of plant species of stiltgrass cover and biomass. Compared to special conservation concern. controls, fall fires reduced Japanese stiltgrass In order to be considered as a candidate cover by 79% and biomass by 90%, while for this drastic treatment, an area should mowing reduced cover by 70% and biomass by meet one or both of these criteria: 95%. Spring fire significantly reduced Japanese stiltgrass cover but not its biomass (P < 0.05 for • Plants of special conservation concern all variables). Hand‐pulling in spring did not are directly threatened by invasive plant significantly change Japanese stiltgrass cover or or greenbrier spread. biomass. Native understory species showed no significant difference in cover or biomass on • Other methods such as herbiciding and 4 prescribed burning have repeatedly treated compared to control plots. failed to transform an area in invasive or aggressive plant cover to one dominated by a variety of characteristic serpentine 1 Fryer (2011b) barrens plant species. 2 Barden (1991) 3 Bowles et al. (2007) 4 Flory and Lewis (2009), quoted in Fryer (2011b) 77

Alternative methods to compare with suppression by faster‐growing but less fire‐ late summer burning include repeated tolerant tree seedlings and saplings such as broadcast application of a pre‐emergent red maple, black‐gum, tuliptree, white ash herbicide such as imazapic (trade name and black cherry. The trigger for prescribed Journey), pendimethalin (Pendulum fire in oak forest stands is a dense growth Aquacap), diphenamid (Enide) or benefin of tree seedlings and saplings that includes (Balan) on areas heavily infested with oaks, which can occur only with relatively stiltgrass, on the theory that eliminating high light availability (canopy openness) competition from stiltgrass will give and low intensity of deer browsing in established native perennial forest under‐ winter, when most tree seedlings and story plants a chance to grow larger and shrubs are consumed. spread. Because stiltgrass is a warm‐season annual, it requires repeated pre‐emergent 4.1.4 Deer management applications during the growing season, The primary deer management tool is starting in March, to prevent germination1. an annual controlled hunt, with hunting There is little point in applying a broad‐ supervised by preserve management staff spectrum foliar herbicide such as and carried out by authorized hunters who glyphosate to combat stiltgrass infestations have passed mandatory proficiency tests. unless followed by seeding or planting Hunters must agree to devote at minimum plugs of native forest understory plants. some reasonable number of hours per With no competition from other species the season to hunting on the site and to remove next cohort of seedlings will quickly restore at least one doe before they are allowed to stiltgrass cover. However, imazameth harvest a buck. (tradename Plateau), applied at a rate of 6 If recreational hunting should fail to ounces per acre, has been used to kill deliver on desired conditions, as measured stiltgrass without killing desirable native in replicate paired quadrats inside and sedges and forbs, and the grass‐specific outside deer exclosures (see Monitoring herbicide sethoxydim (tradenames Poast, deer effects, p. 83), then sharpshooter Vantage), applied during late summer at a culling should be considered as a means of rate of 8 ounces per acre, also provided bringing the deer population down to a excellent (more than 95%) control of level that can then be sustained by annual stiltgrass and released forbs from recreational hunts. A special deer control competition without injuring them2. Great permit related to forest depredation can be care must be taken to keep herbicides well obtained from the Pennsylvania Game away from any area where plant species of Commission by demonstrating that hunting special concern occur. Those that live in the is insufficient to meet a landowner’s goals moist, partly shaded habitats most likely to for tree regeneration or other desired be invaded by stiltgrass include Richard– conditions that are prevented by excessive son’s sedge, barrens chickweed, tufted deer browsing. Permit conditions require hairgrass and small‐leaf white snakeroot. the landowner to provide a reasonable level Limiting regeneration of mesic forest of hunting opportunity to licensed hunters trees in forest/woodlands stands. in the hunting season prior to any cull. Prescribed burning can foster oak Culling usually consists of sharpshooters regeneration in forest and woodland using high‐powered rifles killing groups of settings by releasing oak seedlings from deer from high ground over baiting stations established several weeks prior to the cull. The work is done over a period of days or 1 Tu (2000); Swearingen and Sheherezade (2008) weeks, often at night using infrared scopes. 2 Tu (2000) Venison is dressed and often distributed to

local food banks, soup kitchens and needy be used. Long‐term, if this stratagem should families through the state’s Hunters fail for any species, the next step would be Sharing the Harvest program. Culls are using seed collected at the nearest typically conducted for 1–3 consecutive serpentine barrens where the species is years. Quantitative data on ecosystem still thriving. indicators from replicate paired quadrats The highest‐priority species for aug‐ inside and outside deer exclosures is the mentation from seed collected on‐site are: basis for judging how long culling is necessary to meet the objectives. • species of special conservation concern whose populations are so small that their 4.1.5 Species reintroduction and viability is in question; examples include augmentation Bicknell’s sedge, Richardson’s sedge, Reintroduction. Reintroducing species to Bicknell’s hoary rockrose, New Jersey tea and Elliott’s beardgrass the Unionville Barrens that were once present but are now gone mimics nature’s • additional species of special conservation island population “rescue effect” but on a concern found in further survey work; shorter time‐scale. Species selected for most‐likely candidates are species reintroduction may be planted as seeds or documented historically at the site that as nursery‐reared plugs or potted plants. In have eluded detection in recent years all cases, only wild‐collected seeds from (Table 6, p. 37) one (or preferably more than one) of the • plants whose populations are similarly nearest serpentine barrens sites in eastern low that are host plants for animals of and central Chester County are eligible to special conservation concern, for serve as reintroduction growing stock. instance, wild indigo The highest priority species for rein‐ • post oak, blackjack or Bush’s oak and troduction are grassland species believed dwarf chinkapin oak, which are no longer extirpated from the Unionville Barrens that regenerating; planted stock will need to are either species of special conservation be protected from deer browsing concern (Table 6, p. 37) or have strong • mixtures of the characteristic native grass fidelity to the communities with high con‐ species of serpentine grasslands for servation priority (pp. 30–32). For instance, broadcast seeding in grassland extirpated species native to wetlands restoration areas (Table 1, pp. 22–23) may be reintroduced to restored mixed forb marsh communities. 4.1.6 Maintaining esthetic and historical preservation standards Augmentation. Remnant populations that have dwindled to such small size or have A significant part of the value of a such low recruitment rates that they are in natural area is esthetic. Although no danger of being extirpated if not “rescued” quantitative metrics are suggested, are the primary candidates for augmenta‐ “natural” appearance is a desired condition. tion planting. Mass plantings in restoration The Unionville Barrens’ high ecological, areas of the characteristic native grass geological, historical and conservation species of the serpentine grasslands also importance makes the site an exceptional come under the rubric of augmentation. attraction to a wide range of visitors with both casual and professional interest in the Grassland restoration areas, not existing site and how it is managed. It will serve as a grasslands, are the appropriate sites for model and showpiece for best management augmentation plantings. Only seed practices and successful restoration results, collected in the Unionville Barrens or plugs furthering NLT’s reputation for high‐quality or potted plants grown from them should land management. 79

All management operations should be inconspicuous, as much as possible not done with esthetic consequences in mind. easily discernible from a distance. For instance, tree‐cutting should leave few Conserving historical and archaeo‐ or no artificial traces. Trunks should be logical resources provides a sense of the flush‐cut to the ground surface and all land‐use history of the site for visitors and wood, slash and trimmed brush taken off‐ protects useful information for future site or chipped for use on trails. Firebreaks historians to unearth. Heavy equipment and equipment access paths should be should be kept away from quarries, mining curvilinear with no long straight‐line views. pits and other sites where archaeological Deer exclosures erected to monitor evidence of historical land use may persist browsing effects on desired conditions at or just under the ground surface. should be well engineered and durable but

4.2 Monitoring Monitoring is an indispensible part of (see Appendix D, pp. 149–153, for the adaptive management, generating practical meanings of control and replication in new knowledge that is promptly put to use. adaptive management). Quadrats are It brings consistency, rigor and efficiency to subsamples, not replicates. Each plot may the process of tracking changes in contain one to several quadrats. conditions resulting from management Suggested procedures for quadrat actions and external causes. The key to surveys are summed up in these steps: monitoring is to choose an appropriate set (1) Allocate quadrats among high‐priority of indicators to reflect progress in achieving vegetation types (pp. 30–32) and and sustaining the desired conditions. management units (Map 10) by Indicators, also called metrics, are quanti– stratified random sampling using GIS tative attributes of specific ecosystem data layers, random numbers and a set components used to characterize, evaluate of acceptance/rejection criteria such as and communicate the condition of an distance from the edge of a manage‐ ecosystem at a specific time or across a ment unit (for more details on stratified sequence of intervals. Indicators must be random sampling, including guidance measurable at a reasonable cost and within on randomizing monitoring locations, a feasible timeframe. Monitoring is in see Appendix D, p. 149–153). essence an audit—a systematic, disciplined approach to evaluate and improve the (2) Stratify quadrats in these location effectiveness of management. categories: • seven management units (M.U.s) 4.2.1 Quadrat monitoring of vascular plant species cover • three vegetation categories: ° grassland (including gravel forb Quadrat locations and data collection community) methods. A quadrat is a small area of land, ° forest/woodland often square, rectangular or circular, on ° wetland which ecological data are collected. It is (3) Distribute quadrats in proportion to distinguished from a plot, a term better area in each land type in each M.U.: reserved, to head off confusion, for a unit of land on which a treatment or combination • 1–3 in each M.U. in existing grassland of treatments is applied (trial plot) or not • 1–3 in each M.U. in forest/woodland applied, for comparison (control plot); a within grassland management area plot is the fundamental unit of replication

• 1–3 in each M.U. in forest/woodland tags should be left in place after the monit‐ outside grassland management area oring period is over in case the quadrat • at least 6 total in wetlands might someday be needed again to evaluate (4) Employ predetermined acceptance/ some future management trial or to extend rejection criteria to decide which GIS‐ the assessment of long‐term trends into areas not covered by permanent quadrats. randomized quadrat locations to accept when examined in the field; example: a Data analysis. Using appropriate quadrat in existing grassland must have statistical methods1, two components of at least 20% cover but no more than vascular plant species diversity (richness 80% cover of gravel forb community. and evenness) are analyzed separately2 at three scales (alpha, beta and gamma). (5) Lay out quadrats 25 m2 (270 square feet) in area, as squares 5 m (~ 16½ Alpha (α) is the richness within habitats, expressed as the average number of species feet) on a side or rectangles (1 m × 25 in the 25‐m2 (270‐square foot) vegetation m, 2 m × 7.5 m, etc.) with corners monitoring quadrats. Gamma ( ) is the marked by steel rebar driven into the γ overall richness across the entire Unionville ground, identified by fire‐resistant steel Barrens landscape, expressed as the total tags with engraved numbers attached to number of species across all quadrats rebar with fire‐resistant wire, and georeferenced using GPS. within a vegetation category. Beta (β) is the species turnover among habitats within the (6) In each monitoring year (every third to landscape, a measure of habitat diversity. fifth year), employ a botanist to Harrison’s modification of Whittaker’s beta: estimate and record percent cover of H = 100 × ((( / max) – 1)/(N – 1)) every species in three layers (0–1 m, 1– β γ α 2 m and > 2 m above the ground (where αmax = highest number of species in surface) and at two times during the any quadrat and N = number of quadrats) is season (May–early June and late an index of β diversity among multiple August–September) to capture species quadrats (N) surveyed across a landscape. with different phenologies. It is used to compare different landscapes or surveys conducted in different years in (7) Record data in computer spreadsheets, the same landscape. It can range from 0 (no organized as specified by a qualified turnover among samples) to 100 (every biostatistician employed to conduct the sample has a unique set of species). analyses. Evenness (the inverse of dominance) Additional stratified random sampling among species in each quadrat is calculated locations will be needed to assess the using a variation of Simpson’s index: effects of future management trials if they are conducted in areas without enough E1/D = 100 × (1/Σ((ni (ni – 1))/(N (N – 1)))/α permanent monitoring quadrats to provide where ni = abundance of the ith species, N = replication and control. They can be total abundance, and α = number of species permanent or short‐term, depending on the in the quadrat (to transform fractional nature of the management trial and how percent cover quantities to integer values, long indicators need to be measured to abundance = estimated percent cover × assess the results. A mixture of permanent and temporary monitoring quadrats may be 1 Reviewed in Magurran (2004) used for a management trial. Any 2 The widely used index derived from information theory monitoring quadrat intended for temporary by Shannon and Wiener, commonly called the Shannon use should be installed in the same way as a index, is not used because it confounds richness and evenness. Different values give no indication whether the permanent quadrat so that credible com‐ disparities reflect different richness, different evenness, parisons can be made. Corner markers and or both (Magurran 2004). 81

100). E1/D is independent of species mapping them or counting stems in richness. It can range from near 0 (one representative 2‐m × 2‐m quadrats and species is highly dominant) to 100 (all extrapolating to the entire area of coverage species are equally abundant). to estimate total population numbers. Some indicators consist of groups of 4.2.3 GIS metrics species with key traits in common, with no need to distinguish individual species. Some indicators (first three items in Evaluating such species categories, called Table 7, p. 50) are evaluated periodically functional groups, requires the percent using digital mapping software and recent cover of multiple species to be summed high‐resolution satellite imagery. Changes together. Functional groups used as over time in the areas covered by particular indicators are as follows (see Tables 3 and vegetation types are computed using GIS 4, pp. 34, 35; individual species are listed in image classification software. Appendix B, pp. 111–143): 4.2.4 Monitoring bird populations • native trees (31 species marked in Appendix B as native and TD or TE) Key bird indicators are the numbers of confirmed nesting pairs of bird species of • native shrubs (25 species marked as special conservation concern that are native and SD) expected to benefit from grassland • native herbaceous plants (219 marked as restoration such as brown thrasher, native and HA, VA, HB, HP or VP) common nighthawk and yellow‐breasted • native perennial warm‐season grasses chat. Annual breeding bird counts, often (12 species marked as native and C4) conducted by skilled volunteer amateurs • native serpentine grassland plants (83 with supervision and quality control by species marked as S1E, S1, S2 or S3) staff naturalists, are used to track short‐ term and long‐term trends in these species. • native herbaceous serpentine grassland plants (72 species marked as HA, VA, HB, 4.2.5 Monitoring arthropod populations HP or VP and S1E, S1, S2 or S3) Most insects and other arthropods of • native woody serpentine grassland special conservation concern can be plants (11 species marked as SD, TD, TE captured and identified and their popula‐ or VW and S1, S2 or S3) tions evaluated only through professional • oaks (10 species in the genus Quercus) surveys conducted by qualified entomol‐ • nonnative plants (74 species marked as ogists. However, in the case of butterflies, it nonnative) is sometimes possible to rely on help from • nonnative herbaceous plants (55 species skilled volunteer amateurs, depending on marked as nonnative) their availability and reliability. It is not practical to estimate arthropod 4.2.2 Monitoring sparsely distributed populations as is sometimes done for plant species of special conservation breeding bird species by counting nesting concern pairs. This is not only because arthropods Some plants of special conservation are far more numerous, but also because concern and host plants of animals of different species have different detection special conservation concern occur as small probabilities and the species‐specific populations that would not be adequately relationships between detection rates and represented in a stratified random sample population numbers are unknown. of quadrats. They are monitored by locating Furthermore, detection probability varies clusters of individuals and periodically among methods, investigators, weather

before and during surveys and other factors Deer‐effects monitoring is also that change from one survey to another. desirable in the forest stands to be However, variation in detection frequency managed to promote oak regeneration, over several survey years can be used by an since a deer population elevated far above experienced entomologist as a rough index the historical norm is one of the most of population trends in a species of special serious risk factors throughout the conservation concern. Northeast to the persistence and integrity of forests dominated by oaks. In a forest 4.2.6 Monitoring deer effects setting it is essential that both exclosed and Monitoring indicators of deer browsing non‐exclosed comparison plots be located effects requires multiple permanent deer where shade is not too dense. To ensure a exclosures. There is no other way to reasonably fast response time of the plant separate the effects of deer from myriad indicators, the tree canopy must be open other effects on plant relative abundance, enough to admit sunlight to the forest floor survival and fecundity. The only practical adequate to support robust and relatively way of monitoring deer effects on highly fast plant growth. Furthermore, the spaces vulnerable (preferred) plant species is to between trees must be large enough that plant them as nursery‐reared plugs in this condition is likely to persist for 10–15 identical phytometer arrays positioned in years or more. Where necessary, trees pairs—an array inside each deer exclosure should be thinned above exclosed and non‐ and a matching one in like conditions just exclosed comparison plots in forest stands outside each exclosure1. Such trials should to decrease the amount of shade uniformly be considered for plant species of special across all monitoring quadrats and conservation concern whose populations at postpone the time when lateral growth of the Unionville Barrens are so small that the remaining trees’ limbs fills in the their viability is in question (Table 5, pp. canopy gaps again. 35–36) and for species targeted for reintroduction (p. 79). 4.2.7 Baseline surveys focusing on ecosystem components of special Care will need to be taken that all conservation concern routine management is the same inside A survey of invertebrate species, each exclosure as in its adjacent unfenced especially butterflies and moths, is needed comparison area. Exclosure fences that are to establish whether any of the rare species easily disassembled and reassembled and known to inhabit serpentine barrens in the whose permanent corner posts will not be region are present at the Unionville damaged by prescribed fire are ideal for Barrens. The Pennsylvania Natural Heritage this reason. The area within each exclosure Program (Western Pennsylvania should be at least 100 m2 (1,100 sq. ft.) to Conservancy, Pittsburgh and Middletown), enable the fence to contain an entire 25‐m2 (270‐square foot) monitoring quadrat with the Carnegie Museum of Natural History’s an adequate buffer zone (2.5 m/8 feet Section of Invertebrate Zoology wide) to minimize edge effects. To account (Pittsburgh) and the Academy of Natural for expected high spatial variation in deer Sciences (Philadelphia) work together on effects, a minimum of three and preferably similar surveys statewide and are best six 5‐m × 5‐m grassland monitoring positioned and qualified to collect the data quadrats need to be paired with an adjacent and interpret the results. monitoring quadrat of the same size Surveys of birds, amphibians, turtles surrounded by a deer exclosure fence. and snakes are also a priority, although less urgent than invertebrate surveys, which are 1 Latham et al. (2009) more likely to find imperiled species. A 83

well‐supervised volunteer program is likely marsh, sparsely vegetated vernal pool and to produce useful data on bird species red maple – black‐gum palustrine forest breeding at the site. Herpetological survey (pp. 31–32)—are not visible in aerial work must be done by professionals. photos and thus were mapped only An urgent priority is to undertake a approximately and incompletely for this thorough search for plant species of special plan (Map 8). No attempt was made to map conservation concern that are known to serpentine seeps (see cover photo), which, exist at the site only as small, highly together with serpentine grasslands and localized populations and those gravel forb communities, are ranked documented as having been present highest in conservation priority of all historically but not seen in recent years. It communities at the site. All of the wetlands is probable that there are additional are important out of proportion to their remnant populations so small as to have small total area because a diverse array of escaped observation so far. Accurate plant and animal species, including some of documentation of the population size and special conservation concern, are distribution of each such species is needed absolutely dependent on them to supply as a baseline for developing recovery their habitat needs. Effective stewardship strategies and for measuring progress of these small and exceptionally sensitive toward long‐term viability. communities requires that all occurrences be found and their locations and The wetlands at the Unionville boundaries be accurately mapped. Barrens—serpentine seep, mixed forb

4.3 Stewardship task priorities and timeframe The main criteria for prioritizing monitoring of vegetation quadrats, and restoration and management tasks are: surveys of rare arthropod species. • priority of the specific resource(s) that Task priorities are outlined here in the task is intended to safeguard three ways: • severity, scope, irreversibility and time‐ (1) Brief bullet‐point description of each sensitivity of the risk(s) that the task is management unit as it stood in 2011 intended to avert before management began, with its The purpose here is not to provide a specific task priorities specific calendar, which would soon be (2) List of barrens‐wide management tasks obsolete in any case because the farther with each one’s triggering event, into the future one plans, even as soon as earliest start time and relative priority next year, the more unpredictable key (Table 9, pp. 86–89) events or their timing become. Such events (3) Summary of most‐urgent stewardship may include, for example, drought or tasks recommended for implementation prolonged wet weather, NLT’s acquisition in 2012–2013 (Table 10, p. 91) of more of the barrens area, and unforeseen responses of invasive species to tree 4.3.1 Management units clearing. On the other hand, it is urgent to The acreage of each management unit begin some tasks as soon as resources can (M.U.) broken down by 2011 ownership be mustered (and then repeat them at parcel, existing grassland, grassland regular intervals thereafter), no matter restoration area and forest management what unexpected events may occur, for area, is given on Table 8 (opposite). instance, prescribed burning, long‐term

Management unit 1 and largest blocks of existing grassland • Mostly mesic forest with a small area of (1.9 acres) and a large area of oak‐ existing grassland (0.7 acre) rapidly dominated forest (14.3 acres). succeeding to woodland and forest. • Although small in area, the now‐wooded • Both grassland and forest are heavily portion of the grassland management invaded by autumn‐olive. area (4.6 acres) is high in priority for • Highest priorities are to remove autumn‐ clearing non‐barrens tree species and olive, clear non‐barrens tree species from starting to apply prescribed fire. the grassland management area and Management unit 3 begin prescribed burning. • Area of existing grassland has dwindled • Only known stand of a species of special to 0.2 acre but wooded grassland conservation concern, Bicknell’s hoary management area is large, 14.3 acres. rockrose, is localized around the Heckert‐ • Invasion by mesic forest species and soil NLT parcel boundary near the gate along data (Map 6) indicate deep soils in the Cannery Road (Map 8)—an area to be eastern half, which also includes a major avoided as an access route for vehicles or high‐quality wetland area (Map 8). heavy machinery. • Entire barrens area’s largest wetland is in Management unit 2 the southwestern corner of M.U. 3. • Includes one of the two highest‐quality (continued on p. 90) Table 8. Sizes of management units and their component grassland and forest management areas, broken down by ownership in 2011. All quantities are in acres.

existing area targeted for grassland forest (2010) grassland management management management management unit grassland restoration area total area unit total NLT parcel 0.5 4.6 5.1 15.5 M.U. 1 Heckert parcel 0.2 0.8 1.0 1.3 total 0.7 5.5 6.1 16.8 22.9 NLT parcel 1.7 4.0 5.7 8.2 M.U. 2 Heckert parcel 0.2 0.6 0.7 6.1 total 1.9 4.6 6.4 14.3 20.7 M.U. 3 (all in NLT parcel) 0.2 4.2 4.4 9.0 13.3 M.U. 4 (all in NLT parcel) 0.2 0.9 1.1 3.5 4.6 NLT parcel 1.7 4.0 5.7 8.2 M.U. 5 Heckert parcel 0.1 1.0 1.1 9.8 total 1.8 5.0 6.8 18.0 24.8 Kramkowski parcel 1.7 16.9 18.6 3.1 M.U. 6 Heckert parcel 0.3 0.4 0.8 1.8 total 2.0 17.4 19.4 4.9 24.2 M.U. 7 (all in Heckert parcel) 0.2 3.2 3.4 3.0 6.4 grand total 7.0 40.6 47.6 69.3 117.0

Table 9. Prioritization of major recommendations for restoration and management of the Unionville Barrens. Priority ranks: 1 = highest (urgent to sustain globally rare communities and imperiled species); 2 = high (urgent to sustain regionally rare communities and local genotypes of key species); 3 = intermediate (required to achieve or sustain desired conditions but less time‐sensitive); 4 = low (required to achieve or sustain desired conditions but can be delayed for a period of years). stewardship task trigger earliest start time priority TREE CLEARING, THINNING & REPLACEMENT Clear firebreaks and equipment access paths (Map 9) NLT acquisition of land/management rights 2012 1 Selectively remove trees in wooded portions of Total area of grassland + gravel forb commu‐ 2012 1 grassland management areas (Map 10) nity + serpentine seep less than 45 acres Begin propagating savanna oaks (post oak, blackjack/ As soon as feasible 2012 1 Bush’s oak, dwarf chinkapin oak) from seed gathered on‐site for replanting in cleared areas Selectively thin trees in forest management areas Little or no survival of oak seedlings into 2012 2 (Map 10) sapling stage Convert red‐cedars to dead snags by where possible Most red‐cedars alive 2012 2 by torching in prescribed burns Plant savanna oak seedlings (propagated from seed Trees cleared and propagated seedlings large 2014 2 gathered on‐site) in tree tubes widely spaced across enough to plant grassland management areas cleared of trees Begin propagating forest oaks (black oak, scarlet oak, As soon as feasible 2012 3 northern red oak, white oak, chestnut oak) and pignut hickory from seed gathered on‐site for replanting in thinned areas Plant forest oak and pignut hickory seedlings (of local Trees thinned and propagated seedlings 2014 3 provenance) in tree tubes under canopy gaps in forest large enough to plant management areas Convert red‐cedars that survive fires to dead snags by Most red‐cedars alive in areas where two After a given area has 3 basal bark herbiciding prescribed burns have been conducted been burned twice Thin of dense stands of red‐cedar Monospecific stands of red‐cedar have closed 2012 3 canopy PRESCRIBED BURNING Conduct prescribed burns in tree removal areas Trees removed recently and fuels sufficient 2012 1 to achieve near‐total ground coverage by fire

stewardship task trigger earliest start time priority Conduct prescribed burns in open woodland and Abundant nonnative invasive species in 2012 1 adjoining savanna understory Conduct late summer prescribed burns in forest Relatively dense cover of stiltgrass and low 2012 1 management areas (Map 10) for invasive species or no cover of autumn‐olive control Conduct spring prescribed burns in forest Relatively dense cover of garlic mustard, 2012 2 management areas (Map 10) for invasive species Japanese honeysuckle, Amur honeysuckle, control Oriental bittersweet, multiflora rose, winged euonymus, Japanese barberry or wineberry and low or no cover of autumn‐olive Conduct prescribed burns in forest management areas Dense growth of tree seedlings and saplings, After deer population 2 (Map 10) for oak regeneration including oaks, and relatively open tree is reduced to levels canopy that allow dense tree seedling growth Conduct trials of late‐summer prescribed burning in Tall warm‐season grasses forming dense, After warm‐season 2 restored grassland (tree removal areas) overlying continuous cover with little diversity and few grass cover is thick soils forbs established Conduct prescribed burns in existing grasslands (Map Invasion by greenbriers or other woody Concurrent with 3 4) plants burning in adjoining tree removal areas INVASIVE & AGGRESSIVE SPECIES MANAGEMENT Conduct trials of autumn‐olive removal by mechanical Presence of autumn‐olive in grassland, 2012 1 removal and basal‐bark herbiciding (pp. 74–75) woodland or forest Periodically remove autumn‐olive, choosing methods Presence of autumn‐olive in grassland, After first removal in 1 according to site conditions and other constraints as woodland or forest a given area indicated by trial results Spot‐herbicide nonnative invasive plant cover in tree Persistence of invasive species after After a given area has 2 removal areas prescribed burning been burned Herbicide stiltgrass cover in forest and woodland Failure of fall prescribed burning to stiltgrass After a given area has 2 stands and plant replacement forest understory forbs within a reasonable time been burned twice Eradicate ailanthus NLT acquisition of land/management rights 2012 3 Eradicate black locust NLT acquisition of land/management rights 2012 3

87 (Table continues on next page.) 88 Table 9 (continued)

stewardship task trigger earliest start time priority Reduce greenbrier density by partial soil organic Failure of repeated prescribed burning to After a given area has 3 matter removal with off‐site disposal push back greenbrier advancing front been burned twice Reduce woody invasive species cover by partial soil Failure of repeated prescribed burning or After a given area has 3 organic matter removal with off‐site disposal other methods to establish dominance by been treated by less‐ characteristic serpentine grassland species costly methods DEER MANAGEMENT Organize and supervise annual deer hunt intensively Every year Ongoing 2 targeting females; encourage doe hunting on adjacent private lands Obtain special deer control permit and contract Little or no survival of oak seedlings into 2012 3 professional deer culling services sapling stage and other deer‐related indicators in the “poor” to “fair” range REINTRODUCTION & AUGMENTATION OF SPECIES OF SPECIAL CONSERVATION CONCERN Augment plant species of special conservation NLT acquisition of land/management rights 2012 2 concern and host plants of animals of special conservation concern whose on‐site populations are too small for long‐term viability Reintroduce extirpated plant species of special Year‐long baseline survey confirms no 2013 4 conservation concern population remains INDICATOR DATA ACQUISITION, ANALYSIS & APPLICATION TO MANAGEMENT Intensively search for small remnant populations of NLT acquisition of land/management rights 2012 1 plant species of special conservation concern Install monitoring quadrats at stands of plant species NLT acquisition of land/management rights 2012 1 of special conservation concern whose populations are small and localized Contract qualified entomologists to conduct baseline As soon as feasible 2012 1 survey of Lepidoptera and other arthropods, emphasizing species of special conservation concern Install network of permanent quadrats to monitor all NLT acquisition of land/management rights 2012 1 vascular plant species’ cover in existing grasslands, forest/woodland in grassland management areas, forest management areas and wetlands

stewardship task trigger earliest start time priority Collect baseline data in permanent quadrats Completion of quadrat installation 2012 1 Contract qualified biostatistician to analyze As needed 2013 1 monitoring data and facilitate staff discussion of results and their consequences for management Collect periodic data in long‐term quadrats Every 3–5 years 2015 2 Contract qualified entomologists to conduct periodic Every 3–5 years 2015 2 surveys of Lepidoptera (and other arthropods groups likely to include species of special conservation concern, if practical) Build at least two deer exclosures in existing NLT acquisition of land/management rights 2012 2 grasslands, at least two in forest/woodland in grassland management areas and at least two in forest management areas Collect baseline data on species cover and other deer‐ Completion of exclosure construction 2012 2 related indicators in paired monitoring quadrats at each exclosure, one inside and one outside Collect periodic data on species cover and other deer‐ Every 2–3 years 2014 2 related indicators in paired monitoring quadrats at each exclosure Georeference locations and extent of wetlands NLT acquisition of land/management rights; 2014 2 throughout site, refining rough boundaries on Map 8 update every 10 years and locating occurrences not yet mapped, including serpentine seeps Assess extent of serpentine gravel forb community Availability of new high‐resolution photos on 2012 3 and proportion of grassland in prairie versus savanna which image classification software can using recent satellite photos distinguish communities of interest Establish team of skilled volunteer help and supervise NLT acquisition of land/management rights 2012 3 annual count of nesting bird species of special conservation concern Supervise collection of baseline breeding bird data Establishment of reliable birding group 2012 3 focusing on species of special conservation concern Supervise collection of annual breeding bird data Every year 2013 3 focusing on species of special conservation concern

• Tree‐clearing and burning to expand and • Includes nearly half of the grassland stabilize the small remnant grassland (0.2 management area of the entire Unionville acre) before it disappears is a high Barrens (17.4 of 40.6 acres) and 29% (2 priority, but grassland restoration of the acres) of the total existing grassland. full area (4.4 acres) has a lower priority • Contains the largest and best examples of than other M.U.s. serpentine seep in the Unionville Barrens. • Selective tree‐thinning in larger wetland • Outstanding potential for restoration but to sunlight herbaceous layer and follow‐ rapidly being invaded by forest trees and up control of any invasive species a severe infestation of autumn‐olive. outbreak are intermediate priorities. • Highest priority for additional land Management unit 4 protection at the Unionville Barrens; • Narrow area between the abandoned part because of rapid forest succession and of Oak School Road and Corundum Run invasive species proliferation, protection • Includes one very small but high‐quality and stewardship are of the highest grassland with the only known stand of a urgency. species of special conservation concern, Management unit 7 the state‐endangered Bicknell’s sedge, on • Shows signs of having been pastured a knoll near the center of the M.U. more recently than anywhere else in the • Grassland has shrunken (to 0.2 acre) and barrens and planted in nonnative cool‐ is near disappearing. season pasture grasses. • Wooded perimeter of the knoll is a high‐ • Grassland management area (3.2 acres) priority site for grassland restoration, currently has few if any characteristic with due diligence to avoid harming the serpentine grassland plants. rare species stand. • Because of the absence of existing stands Management unit 5 of species of special conservation • NLT parcel portion includes one of the concern, grassland restoration has the two highest‐quality and largest blocks of lowest priority here of anywhere in the existing grassland (1.7 acres) and a large Unionville Barrens; however, when area of oak‐dominated woodland and restored, the grassland will contribute forest (8.2 acres). significantly to the overall quality and viability of the barrens. • Most scenically outstanding area of remaining serpentine grassland, with 4.3.2 Highest‐priority stewardship tasks views of rolling hills across the barrens. for 2012–2013 This is currently the showpiece of the Of the stewardship tasks required to Unionville Barrens and will be achieve and sustain desired conditions at significantly enhanced by restoration of the Unionville Barrens (Table 9, pp. 86–89), an additional 5 acres of grassland. the most urgent to begin implementing in • Existing grassland and surrounding the first two years are those most directly woodland and forest have highest priority aimed at preventing further deterioration for prescribed burning of the entire of the globally rare serpentine barrens barrens area. communities and additional extirpations Management unit 6 among the imperiled species remaining at • Largest M.U. (24.2 acres) and the only one the site. They are summarized in Table 10 containing side‐oats grama (Map 8), a (facing page). threatened species in Pennsylvania.

Table 10. Summary of highest‐priority stewardship tasks for 2012–2013 (numbered for convenience in cross‐referencing, not in order of priority or urgency). task location(s) 1. Clear firebreaks and equipment access paths (Map 9) M.U.s 1, 2, 3, 4, 5 2. Cut most trees in grassland management areas, leaving certain trees intact M.U.s 1, 2 (pp. 68–71) 3. Thin trees in upland forest management areas and cut all saplings of mesic M.U.s 1, 2 forest tree species, leaving all oak and hickory saplings intact (pp. 68–71) 4. Propagate savanna oak species from seed collected on‐site, possibly in Off‐site cooperation with a local wholesale native plant nursery (p. 79) 5. Collect seed of native serpentine grasses in existing grassland and plant in M.U.s 1, 2 grassland restoration areas after tree clearing (p. 79) 6. Conduct spring prescribed burns in tree removal areas, open woodland M.U.s 1, 2, 3, 4, 5 and adjoining grassland, leaving at least ½ of each of the larger existing grassland areas (in M.U.s 2 and 5) unburned in any one year (pp. 71–73) 7. Conduct adaptive management trials of late‐summer prescribed burns in M.U.s 1, 2 selected plots within forest management areas to control stiltgrass and invasive woody plants other than autumn‐olive (p. 73) 8. Remove autumn‐olive using a combination of mechanical removal and M.U.s 1, 2, 3, 4, 5 basal‐bark herbiciding (p. 74–75) 9. Spot‐herbicide localized outbreaks of nonnative invasive plant cover (p. M.U.s 1, 2, 3, 4, 5 74) 10. Continue annual deer hunt intensively targeting females; encourage doe Entire area hunting on adjacent private lands (p. 78) 11. Conduct baseline survey of plant species of special concern and host plant Known stands: species for animals of special conservation concern that are present in M.U.s 1, 2, 3, 4 very low numbers at the site and have poor prospects for long‐term population viability without intervention (p. 82) 12. Conduct searches for small remnant populations of plant species of special Entire area conservation concern (p. 83–84) 13. Install monitoring quadrats at stands of plant species of special Known stands: conservation concern whose populations are small and localized (p. 82) M.U.s 1, 2, 3, 4 14. Contract qualified entomologists to conduct baseline survey of At minimum, Lepidoptera and other arthropod groups likely to include species of M.U.s 2, 5 special conservation concern (pp. 82, 83) 15. Begin installing network of permanent quadrats to monitor species cover M.U.s 1, 2, 3, 5 in existing grasslands, forest/woodland in grassland management areas, forest management areas and wetlands (pp. 80–81) 16. Collect baseline data in long‐term quadrats (pp. 80–81) M.U.s 1, 2, 3, 5 17. Begin building deer exclosures in existing grasslands, forest/woodland in M.U.s 1, 2 grassland management areas and forest management areas (p. 83) 18. Collect baseline data on species cover in paired monitoring quadrats at M.U.s 1, 2 each deer exclosure—one inside and one outside (pp. 80–81) 19. Contract biostatistician to analyze monitoring data and facilitate staff Off‐site discussion of results and their consequences for management (p. 80–82)

References Cited

Adler, P. B., J. HilleRisLambers, P. C. Kyriakidis, Berkeley, E. and D. S. Berkeley (eds.). 1992. The Q. Guan and J. M. Levine. 2006. Climate Correspondence of John Bartram 1734‐1777. variability has a stabilizing effect on the University Press of Florida, Gainesville. 808 coexistence of prairie grasses. Proceedings of pp. the National Academy of Sciences 103: Bowles, M. L., K. A. Jacobs and J. L. Mengler. 12793–12798. 2007. Long‐term changes in an oak forest’s Anderson, R. C., E. A. Corbett, M. R. Anderson, G. woody understory and herb layer with A. Corbett and T. M. Kelley. 2001. High white‐ repeated burning. Journal of the Torrey tailed deer density has negative impact on Botanical Society 134: 223‐237. tallgrass prairie forbs. Journal of the Torrey Bravo, M. A. 2005. Fact sheet: Japanese Botanical Society 128: 381‐392. honeysuckle. Alien Plant Working Group, Anderson, R. C., D. Nelson, M. R. Anderson and Plant Conservation Alliance, Bureau of Land M. A. Rickey. 2005. White‐tailed deer Management, Washington, D.C. 3 pp. (Odocoileus virginianus Zimmerman) (www.nps.gov/plants/alien/fact/loja1.htm) browsing effects on tallgrass prairie forbs: Brooks, R. R. 1987. Serpentine and Its diversity and species abundances. Natural Vegetation: a Multidisciplinary Approach. Areas Journal 25: 19‐25. Dioscorides Press, Portland, Oregon. 454 pp. Anderson, R. S. 1971. Butterflies of the Cleaves, E. T., J. Edwards, Jr. and J. D. Glaser. serpentine barrens of Pennsylvania. 1968. Geologic Map of Maryland. Maryland Entomology News 81: 5‐12. Geological Survey, Baltimore. (ArcGIS format Barden, L. S. 1987. Invasion of Microstegium at pubs.usgs.gov/of/2005/1325/; accessed vimineum (Poaceae), an exotic, annual, shade‐ 2011‐08‐24) tolerant, C grass, into a North Carolina 4 Clements, F. E. and G. W. Goldsmith. 1924. The floodplain. American Midland Naturalist 118: Phytometer Method in Ecology: the Plant and 40‐45. Community as Instruments. Carnegie Barton, A. M. and M. D. Wallenstein. 1997. Institution of Washington, Washington, D.C. Effects of invasion of Pinus virginiana on soil 512 pp. properties in serpentine barrens in Commission for Environmental Cooperation. southeastern Pennsylvania. Journal of the 2006. Ecological Regions of North America: Torrey Botanical Society 124: 297‐305. Level I‐III [map]. Commission for Batcher, M. S. and S. A. Stiles. 2000. Element Environmental Cooperation (Montreal, stewardship abstract for Lonicera maackii Quebec, Canada), The Atlas of Canada (Rupr.) Maxim (Amur honeysuckle), Lonicera (Ottawa, Ontario, Canada), National Atlas of morrowii A. Gray (Morrow’s honeysuckle), the United States (Reston, Virginia, U.S.A.), Lonicera tatarica L. (Tatarian honeysuckle), Instituto Nacional de Estadística, Geografía y Lonicera × bella Zabel (Bell’s honeysuckle), Informatica (Aguascalientes, Aguascalientes, the bush honeysuckles. The Nature Mexico). Conservancy, Arlington, Virginia. 12 pp. Conestoga‐Rovers & Associates. 2010. Bergmann, C. and J. M. Swearingen. 2005. Fact Serpentine barrens restoration and sheet: multiflora rose. Alien Plant Working management plan: Jerrehian estate—Fern Group, Plant Conservation Alliance, Bureau of Hill eastern serpentine barren, West Goshen Land Management, Washington, D.C. 3 pp. Township, Chester County, Pennsylvania. (www.nps.gov/plants/alien/fact/romu1.htm) Unpublished report prepared for Jerrehian Partners, Conshohocken, Pennsylvania. 51 pp.

Converse, C. K. 1984. Element stewardship Eckert, G. E. (ed.). 2009. Interim technical abstract for Robinia pseudoacacia, black guidance on defining meaningful desired locust. The Nature Conservancy, Arlington, conditions for natural resources, version 1.0. Virginia. 14 pp. National Park Service, Biological Resources Management Division, Fort Collins, Colorado. Cotterell, M. 2004. The Terracotta Warriors: the 145 pp. Secret Codes of the Emperor's Army. Bear and Company, Rochester, New York. 336 pp. Engel, E. C., J. F. Weltzin,, R. J. Norby and A. T. Classen. 2009. Responses of an old‐field plant Custer, J. F. 1996. Prehistoric Cultures of Eastern community to interacting factors of elevated Pennsylvania. Pennsylvania Historical and [CO ], warming, and soil moisture. Journal of Museum Commission, Harrisburg. 383 pp. 2 Plant Ecology 2: 1‐11. Dale, V. H. and S. C. Beyeler. 2001. Challenges in Erdman, K. 1977. National Natural Landmarks the development and use of ecological evaluation report: Unionville Serpentine indicators. Ecological Indicators 1: 3‐10. Barrens. Unpublished, National Park Service, Darlington, W. 1826. Florula Cestrica: an Essay Philadelphia. 11 pp. Towards a Catalogue of the Phaenogamous Fike, J. 1999. Terrestrial and Palustrine Plant Plants, Native and Naturalized, Growing in the Communities of Pennsylvania. Pennsylvania Vicinity of the Borough of West‐Chester, in Department of Conservation and Natural Chester County, Pennsylvania ... Simeon Resources, Harrisburg, The Nature Siegfried, West Chester, Pennsylvania. 152 pp. Conservancy, Middletown, PA, and Western Darlington, W. 1837. Flora Cestrica: an Attempt Pennsylvania Conservancy, Pittsburgh. 86 pp. to Enumerate and Describe the Flowering and Flory, S. L. and J. Lewis. 2009. Nonchemical Filicoid Plants of Chester County ... Simeon methods for managing Japanese stiltgrass Siegfried, West Chester, Pennsylvania. 640 pp. (Microstegium vimineum). Invasive Plant Day, G. M. 1953. The Indian as an ecological Science and Management 2: 301‐308. factor in the northeastern forest. Ecology 34: Folke, C., S. Carpenter, B. Walker, M. Scheffer, T. 329‐346. Elmqvist, L. Gunderson and C. S. Holling. Denevan, W. M. 1992. The pristine myth: the 2005. Regime shifts, resilience and landscape of the Americas in 1492. Annals of biodiversity in ecosystem management. the American Association of Geographers 82: Annual Review of Ecology, Evolution, and 369‐385. Systematics 35: 557‐581. Dreyer, G. D. 1994. Element stewardship Fryer, J. L. 2009. Euonymus alatus. Fire Effects abstract for Celastrus orbiculatus, Asiatic Information System [online]. U.S. Department bittersweet. The Nature Conservancy, of Agriculture, Forest Service, Rocky Arlington, Virginia. 12 pp. Mountain Research Station, Fire Sciences Laboratory, Missoula, Montana. Dubinsky, E. 1995. The interdependence of (www.fs.fed.us/database/feis/plants/shrub/ vegetation type and soil depth in eastern euoala/introductory.html) temperate serpentine barrens. Unpublished undergraduate thesis, University of Fryer, J. L. 2010. Ailanthus altissima. Fire Effects Pennsylvania, Philadelphia. 12 pp. Information System [online]. U.S. Department of Agriculture, Forest Service, Rocky Dublin, H. T., A. R. E. Sinclair and J. McGlade. Mountain Research Station, Fire Sciences 1990. Elephants and fire as causes of multiple Laboratory, Missoula, Montana. stable states in the Serengeti‐Mara (www.fs.fed.us/database/feis/plants/tree/ail woodlands. Journal of Animal Ecology 59: alt/introductory.html) 1147‐1164. Fryer, J. L. 2011a. Celastrus orbiculatus. Fire Eckardt, N. 1987. Element stewardship abstract Effects Information System [online]. U.S. for Rosa multiflora, rambler rose, Department of Agriculture, Forest Service, multiflowered rose. The Nature Conservancy, Rocky Mountain Research Station, Fire Arlington, Virginia. 8 pp. Sciences Laboratory, Missoula, Montana. 93

(www.fs.fed.us/database/feis/plants/vine/ce Studies capstone report, University of lorb/introductory.html) Pennsylvania, Philadelphia. 75 pp. Fryer, J. L. 2011b. Microstegium vimineum. Fire Hoekstra, J. M., T. M. Boucher, T. H. Ricketts and Effects Information System [online]. U.S. C. Roberts. 2004. Confronting a biome crisis: Department of Agriculture, Forest Service, global disparities of habitat loss and Rocky Mountain Research Station, Fire protection. Ecology Letters 8: 23‐29. Sciences Laboratory, Missoula, Montana. Hoshovsky, M. C. 1988. Element stewardship (www.fs.fed.us/database/feis/plants/gramin abstract for Ailanthus altissima, tree‐of‐ oid/micvim/introductory.html) heaven. The Nature Conservancy, Arlington, Futhey, J. S. and G. Cope. 1881. The History of Virginia. 13 pp. Chester County, Pennsylvania, with Huenneke, L. F., S. P. Hamburg and R. Koide. Genealogical and Biographical Sketches. Louis 1990. Effects of soil resources on plant H. Everts, Philadelphia. 826 pp. invasion and community structure in Gabrielli, R. and T. Pandolfini. 1984. Effect of Californian serpentine grassland. Ecology 71: Mg2+ and Ca2+ on the response to nickel 478‐491. toxicity in a serpentine endemic and nickel‐ Hull, J. C. and S. G. Wood. 1984. Water relations accumulating species. Physiologia Plantarum of oak species on and adjacent to a Maryland 62: 540‐544. serpentine soil. American Midland Naturalist Gerlach, J. A., J. Hough‐Goldstein and J. 112: 224‐234. Swearingen. 2010. Fact sheet: mile‐a‐minute Innes, R. 2009. Rubus phoenicolasius. Fire weed. Alien Plant Working Group, Plant Effects Information System [online]. U.S. Conservation Alliance, Bureau of Land Department of Agriculture, Forest Service, Management, Washington, D.C. 4 pp. Rocky Mountain Research Station, Fire (www.nps.gov/plants/alien/fact/pepe1.htm) Sciences Laboratory, Missoula, Montana. Gigliotti, J. V., Jr. 2010. Carborundum: a (www.fs.fed.us/database/feis/plants/shrub/ diamond in the rough. Student paper, rubpho/introductory.html) Pennsylvania State University, University Jenny, H. 1980. The Soil Resource: Origin and Park. 7 pp. (www.personal.psu.edu/jvg5162/ Behavior. Springer‐Verlag, New York. 377 pp. blogs/JameyGigliotti/Documents/Carborund um A Diamond in the Rough.pdf) Kirk, W. H. and Company. 1883. Breou’s Official Series of Farm Maps, Chester County, Graham, R. W. and E. C. Grimm. 1990. Effects of Pennsylvania: Compiled, Drawn and Published global climate change on the patterns of from Personal Examinations and Surveys. W. terrestrial biological communities. Trends in H. Kirk and Company, Philadelphia. 261 pp. Ecology and Evolution 5: 289‐292. Kruckeberg, A. R. 1984. California Serpentines: Grime, J. P., V. K. Brown, K. Thompson, G. J. Flora, Vegetation, Geology, Soils, and Masters, S. H. Hillier, I. P. Clarke, A. P. Askew, Management Problems. University of D. Corker and J. P. Kielty. 2000. The response California Press, Berkeley. 180 pp. of two contrasting limestone grasslands to simulated climate change. Science 289: 762‐ Kunkle, W. M. 1963. Soil survey of Chester and 765. Delaware Counties, Pennsylvania. U. S. Department of Agriculture, Soil Conservation Guilday, J. E. 1971. The Pleistocene history of Service, Washington, D.C. 124 pages + 80 the Appalachian mammal fauna. Research maps. Division Monographs, Virginia Polytechnic Institute State University 4: 233‐262. Kurtén, B. and E. Anderson. 1980. Pleistocene Mammals of North America. Columbia Haegele, E. 2011. Unionville serpentine University Press, New York. 443 pp. barrens: analyzing the relationship between soil profiles and forest succession rate. Latham, R. E. 1984. National Natural Unpublished Master of Environmental Landmarks review form: Unionville Serpentine Barrens, Chester County,

Pennsylvania. Unpublished, National Park Forests. Pennsylvania Department of Service, Philadelphia. 8 pp. Conservation and Natural Resources, Bureau of Forestry, Harrisburg. 49 pp. Latham, R. E. 1993. The serpentine barrens of temperate eastern North America: critical Leach, M. K. and T. J. Givnish. 1996. Ecological issues in the management of rare species and determinants of species loss in remnant communities. Bartonia 57 Suppl.: 61‐74 prairies. Science 273: 1555‐1558. (Proceedings of the Symposium on Rare Plants Lindeström, P. M. with A. Johnson (ed.). 1925. of Pennsylvania and Adjacent States, 28 March Geographia Americae: with an Account of the 1991, Philadelphia). Delaware Indians: Based on Surveys and Notes Latham, R. 2005. Native grasslands and Made in 1654–1656; Translated from the meadows in Pennsylvania: their history and Original Manuscript with Notes, Introduction current condition. Unpublished report for and an Appendix of Indian Geographical Names Natural Lands Trust, Media, Pennsylvania, with their Meanings by Amandus Johnson. and Pennsylvania Department of Swedish Colonial Society, Philadelphia. 418 pp. Conservation and Natural Resources, Wild Maerz, J. C., V. A. Nuzzo and B. Blossey. 2009. Resource Conservation Program, Harrisburg. Declines in woodland salamander abundance 106 pp. associated with non‐native earthworm and Latham, R. E. 2011. Desired Condition of plant invasions. Conservation Biology 23: 975‐ Grasslands and Meadows in Valley Forge 981. National Historical Park. Natural Resource Magurran, A. E. 2004. Measuring Biological Report NPS/NER/VAFO/NRTR—2011. Diversity. Blackwell Publishing, Malden, National Park Service, Philadelphia, Massachusetts. 256 pp. Pennsylvania. 270 pp. Martin, T. 2000. Weed alert! Euonymus alatus Latham, R. E. and J. F. Thorne. 1997. (Thunb.) Siebold (burning bush, winged Understanding successional trajectories to euonymus, winged wahoo, winged spindle‐ conserve serpentine grasslands [abstract]. tree, Japanese spindle‐tree). Center for Ecological Society of America and the Nature Invasive Species and Ecosystem Health. Conservancy Joint Annual Meeting, (www.invasive.org/gist/alert/alrteuon.html) Albuquerque, New Mexico. McCandless, S. 1998. Invasive Smilax Latham, R. E., J. Beyea, M. Benner, C. A. Dunn, M. rotundifolia associated with changes in A. Fajvan, R. R. Freed, M. Grund, S. B. Horsley serpentine soil syndrome. Unpublished A. F. Rhoads and B. P. Shissler. 2005. undergraduate Honors thesis, Swarthmore Managing White‐tailed Deer in Forest Habitat College, Swarthmore, Pennsylvania. 32 pp. from an Ecosystem Perspective: Pennsylvania Case Study. Audubon Pennsylvania and the Milchunas, D. G., O. E. Sala and W. K. Lauenroth. Pennsylvania Habitat Alliance, Harrisburg. 1988. A generalized model of the effects of 340 pp. (pa.audubon.org/deer_report.html) grazing by large herbivores on grassland community structure. American Naturalist Latham, R. and J. F. Thorne. 2007. Keystone 132: 87‐106. Grasslands: Restoration and Reclamation of Native Grasslands, Meadows, and Savannas in Miller, G. L. 1981. Secondary succession Pennsylvania State Parks and State Game following fire on a serpentine barren. Lands. For the Wild Resource Conservation Proceedings of the Pennsylvania Academy of Program, Pennsylvania Department of Science 55: 62‐64. Conservation and Natural Resources, Mulvihill, R. S. (coordinator) et al. 2011. 2nd Harrisburg. 100 pp. Pennsylvania Breeding Bird Atlas [online]. Latham, R. E. (ed.), M. D. Grund, S. B. Horsley, B. Carnegie Museum of Natural History, C. Jones, W. H. McWilliams, C. K. Nielsen, C. S. Pittsburgh, Powdermill Nature Center, Rector, Rosenberry, R. S. Seymour, B. P. Shissler and Pennsylvania, and Pennsylvania Game D. M. Waller. 2009. Monitoring Deer Effects on Commission, Harrisburg. Forest Ecosystems in Pennsylvania State (www.carnegiemnh.org/atlas)

Munger, G. T. 2001. Alliaria petiolata. Fire ultramafic site in Scotland. New Phytologist Effects Information System [online]. U.S. 135: 561‐566. Department of Agriculture, Forest Service, National Cooperative Soil Survey. Undated. Rocky Mountain Research Station, Fire National cooperative soil characterization Sciences Laboratory, Missoula, Montana. database. (ssldata.nrcs.usda.gov; accessed (www.fs.fed.us/database/feis/plants/forb/all 2011‐09‐05) pet/introductory.html) National Health and Environmental Effects Munger, G. T. 2002a. Lonicera japonica. Fire Research Laboratory. 2011. Level III Effects Information System [online]. U.S. ecoregions of the continental United States. U. Department of Agriculture, Forest Service, S. Environmental Protection Agency. Rocky Mountain Research Station, Fire Refinement of J. M. Omernik, 1987, Sciences Laboratory, Missoula, Montana. Ecoregions of the conterminous United States (www.fs.fed.us/database/feis/plants/shrub/l [map (scale 1:7,500,000)], Annals of the onjap/introductory.html) Association of American Geographers 77: 118‐ Munger, G. T. 2002b. Rosa multiflora. Fire 125. (ftp.epa.gov/wed/ecoregions/us/ Effects Information System [online]. U.S. Eco_Level_III_US.pdf; accessed 2011‐07‐21) Department of Agriculture, Forest Service, Natural Resources Conservation Service. 1999. Rocky Mountain Research Station, Fire Soil Taxonomy: a Basic System of Soil Sciences Laboratory, Missoula, Montana. Classification for Making and Interpreting Soil (www.fs.fed.us/database/feis/plants/shrub/ Surveys (second edition). Agriculture rosmul/introductory.html) Handbook No. 436. U. S. Department of Munger, G. T. 2003. Elaeagnus umbellata. Fire Agriculture, Washington, D.C. 871 pp. Effects Information System [online]. U.S. Natural Resources Conservation Service. 2008. Department of Agriculture, Forest Service, Chrome series [official soil series Rocky Mountain Research Station, Fire description]. U. S. Department of Agriculture, Sciences Laboratory, Missoula, Montana. Washington, D.C. (www.fs.fed.us/database/feis/plants/shrub/ (soils.usda.gov/technical/classification/osd/i elaumb/introductory.htm) ndex.html; accessed 2011‐07‐29) Munger, G. T. 2005. Lonicera spp. Fire Effects Nuzzo, V. 1997a. Element stewardship abstract Information System [online]. U.S. Department for Cirsium arvense, Canada thistle, creeping of Agriculture, Forest Service, Rocky thistle, Californian thistle. The Nature Mountain Research Station, Fire Sciences Conservancy, Arlington, Virginia. 32 pp. Laboratory, Missoula, Montana. (www.fs.fed.us/database/feis/plants/shrub/l Nuzzo, V. 1997b. Element stewardship abstract onspp/introductory.html) for Lonicera japonica, Japanese honeysuckle. The Nature Conservancy, Arlington, Virginia. Müntener, O. 2010. Serpentine and 22 pp. serpentinization: a link between planet formation and life. Geology 38: 959‐960. Nuzzo, V. 2000. Element stewardship abstract for Alliaria petiolata (Alliaria officinalis), Myers, W., J. Bishop, R. Brooks, T. O’Connell, D. garlic mustard. The Nature Conservancy, Argent, G. Storm, J. Stauffer and R. Carline. Arlington, Virginia. 19 pp. 2000. A Gap Analysis of Pennsylvania—2001 Final Report: a Geographic Approach to Panzer, R. 2002. Compatibility of prescribed Planning for Biological Diversity. U. S. burning with the conservation of insects in Department of the Interior, U. S. Geological small, isolated prairie reserves. Conservation Survey and Cooperative Fish & Wildlife Biology 16: 1296‐1307. Research Unit, Pennsylvania State University, Pearre, N. C. and A. V. Heyl, Jr. 1960. Chromite University Park. 790 pp. and Other Mineral Deposits in Serpentine Nagy, L. and J. Proctor. 1997. Soil Mg and Ni as Rocks of the Piedmont Upland, Maryland, causal factors of plant occurrence and Pennsylvania and Delaware. Geological Survey distribution at the Meikle Kilrannoch

Bulletin 1082‐K. U. S. Government Printing Proctor, J. and I. D. McGowan. 1976. Influence of Office, Washington, D.C. magnesium on nickel toxicity. Nature 260: 134‐135. Pennell, F. W. 1910. Flora of the Conowingo barrens of southeastern Pennsylvania. Proctor, J. and S. R. J. Woodell. 1971. The plant Proceedings of the Academy of Natural ecology of serpentine. I. Serpentine Sciences of Philadelphia 62: 541‐584. vegetation of England and Scotland. Journal of Ecology 59: 375‐395. Pennell, F. W. 1912. Further notes on the flora of the Conowingo or serpentine barrens of Radford, A. E. and D. L. Martin. 1975. Potential southeastern Pennsylvania. Proceedings of the Ecological Natural Landmarks, Piedmont Academy of Natural Sciences of Philadelphia Region, Eastern United States. Report to the 64: 520‐539. National Park Service, Washington, D.C. University of North Carolina, Chapel Hill. 249 Pennsylvania Bureau of Topographic and pp. Geologic Survey. 2001. Bedrock geology of Pennsylvania [map]. Pennsylvania Rajakaruna, N., T. B. Harris and E. B. Alexander. Department of Conservation and Natural 2009. Serpentine geoecology of eastern North Resources, Harrisburg. America: a review. Rhodora 111: 21‐108. (www.dcnr.state.pa.us/topogeo/map1/bedm Rawlins, J. E. 2007. Pennsylvania’s ap.aspx) Comprehensive Wildlife Conservation Strategy: Pennsylvania Game Commission and Invertebrates. Carnegie Museum of Natural Pennsylvania Fish and Boat Commission. History, Pittsburgh, for Pennsylvania Game 2005. Pennsylvania Comprehensive Wildlife Commission and Pennsylvania Fish and Boat Conservation Strategy. Harrisburg. 762 pp. Commission, Harrisburg. 227 pp. (www.pgc.state.pa.us/pgc/lib/pgc/SWG/PA Rhoads, A. F. and T. A. Block. 2007. The Plants of WAP.pdf) Pennsylvania, 2nd edition. University of Pennsylvania Natural Heritage Program. 2010. Pennsylvania Press, Philadelphia. 1,042 pp. Invertebrate Species List [online]. Plant Robinson, G. S., L. P. Burney and D. A. Burney. Species List [online]. Vertebrate Species List 2005. Landscape paleoecology and [online]. Western Pennsylvania Conservancy, megafaunal extinction in southeastern New Pennsylvania Department of Conservation York State. Ecological Monographs 75: 295‐ and Natural Resources, Pennsylvania Fish and 315. Boat Commission, Pennsylvania Game Commission. Rowe, P. and J. M. Swearingen. 2005. Fact sheet: (www.naturalheritage.state.pa.us; accessed garlic mustard. Alien Plant Working Group, 2010‐07‐13). Plant Conservation Alliance, Bureau of Land Management, Washington, D.C. 3 pp. Peterjohn, B. 2006. Conceptual ecological model (www.nps.gov/plants/alien/fact/alpe1.htm) for management of breeding grassland birds in the Mid‐Atlantic region. Natural Resources Sather, N. and N. Eckardt. 1987. Element Report NPS/NER/NRR—2006/005. U.S. stewardship abstract for Elaeagnus Department of the Interior, National Park umbellata. The Nature Conservancy, Service, Northeast Region, Philadelphia. 43 Arlington, Virginia. 4 pp. pp. Schultz, C. B. and E. E. Crone. 1998. Burning Plank, M. O., W. S. Schenck and L. Srogi. 2000. prairie to restore butterfly habitat: a Bedrock Geology of the Piedmont of Delaware modeling approach to management tradeoffs and Adjacent Pennsylvania, Delaware for the Fender’s blue. Restoration Ecology 6: Geological Survey Reports of Investigations 244‐252. No. 59. University of Delaware, Newark, for Sladky, R. J. 1981. The interpretation and the Delaware Geological Survey. 52 pp. management of Pink Hill—a serpentine Proctor, J. 1970. Magnesium as a toxic element. barren. Master’s thesis, University of Nature 227: 742‐743. Delaware, Newark. 58 pp.

Sloto, R. A. 2009. The Mines and Minerals of Swengel, A. B. 1996. Effects of fire and hay Chester County, Pennsylvania. Published by management on abundance of prairie author. 469 pp. butterflies. Biological Conservation 76: 73‐85. Spencer, N. R. 2005. Fact sheet: wineberry. Thompson, D. Q. and R. M. Smith. 1970. The Alien Plant Working Group, Plant forest primeval in the Northeast: a great Conservation Alliance, Bureau of Land myth? Proceedings of the Annual Tall Timbers Management, Washington, D.C. 2 pp. Fire Ecology Conference 10: 255‐265. (www.nps.gov/plants/alien/fact/ruph1.htm) Thunhorst, G. and J. M. Swearingen. 2005. Fact Stone, K. R. 2009. Robinia pseudoacacia. Fire sheet: Canada thistle. Alien Plant Working Effects Information System [online]. U.S. Group, Plant Conservation Alliance, Bureau of Department of Agriculture, Forest Service, Land Management, Washington, D.C. 3 pp. Rocky Mountain Research Station, Fire (www.nps.gov/plants/alien/fact/ciar1.htm) Sciences Laboratory, Missoula, Montana. Tu, M. 2000. Element stewardship abstract for (www.fs.fed.us/database/feis/plants/tree/ro Microstegium vimineum, Japanese stilt grass, bpse/introductory.html) Nepalese browntop, Chinese packing grass. Stone, K. R. 2010. Polygonum perfoliatum. Fire The Nature Conservancy, Arlington, Virginia. Effects Information System [online]. U.S. 8 pp. Department of Agriculture, Forest Service, Walker, B. and D. Salt. 2006. Resilience Rocky Mountain Research Station, Fire Thinking: Sustaining Ecosystems and People in Sciences Laboratory, Missoula, Montana. a Changing World. Island Press, Washington, (www.fs.fed.us/database/feis/plants/vine/p D.C. 174 pp. olpef/all.html) Walsh, M. C., J. Deeds and B. Nightingale. 2007. Swearingen, J. M. 2005. Fact sheet: Japanese User’s Manual and Data Guide to the barberry. Alien Plant Working Group, Plant Pennsylvania Aquatic Community Conservation Alliance, Bureau of Land Classification. Pennsylvania Natural Heritage Management, Washington, D.C. 3 pp. Program, Western Pennsylvania Conservancy, (www.nps.gov/plants/alien/fact/beth1.htm) Middletown and Pittsburgh. 167 pp. Swearingen, J. M. 2006. Fact sheet: Oriental Wheeler, A. G., Jr. 1988. Diabrotica cristata, a bittersweet. Alien Plant Working Group, Plant chrysomelid (Coleoptera) of relict Conservation Alliance, Bureau of Land Midwestern prairies discovered in eastern Management, Washington, D.C. 4 pp. serpentine barrens. Entomological News 99: (www.nps.gov/plants/alien/fact/ceor1.htm) 134‐142. Swearingen, J. M. 2010. Fact sheet: Fig Wheeler, A. G., Jr. 1995. Plant bugs buttercup. Alien Plant Working Group, Plant (Heteroptera: Miridae) of Phlox subulata and Conservation Alliance, Bureau of Land other narrowleaved phloxes of the eastern Management, Washington, D.C. 3 pp. United States. Proceedings of the Entomo– (www.nps.gov/plants/alien/fact/rafi1.htm) logical Society of Washington 97: 435‐451. Swearingen, J. M. and A. Sheherezade. 2008. Wieseler, S. 2005. Fact sheet: black locust. Alien Fact sheet: Japanese stiltgrass. Alien Plant Plant Working Group, Plant Conservation Working Group, Plant Conservation Alliance, Alliance, Bureau of Land Management, Bureau of Land Management, Washington, Washington, D.C. 3 pp. (www.nps.gov/ D.C. 4 pp. (www.nps.gov/plants/alien/fact/ plants/alien/fact/rops1.htm) mivi1.htm) Williams, C. E. 2005. Fact sheet: exotic bush Swearingen, J. M. and P. D. Pannill. 2009. Fact honeysuckles. Alien Plant Working Group, sheet: Tree of heaven. Alien Plant Working Plant Conservation Alliance, Bureau of Land Group, Plant Conservation Alliance, Bureau of Management, Washington, D.C. 3 pp. Land Management, Washington, D.C. 5 pp. (www.nps.gov/plants/alien/fact/loni1.htm) (www.nps.gov/plants/alien/fact/aial1.htm) Williams, S. L., S. B. McLaren and M. A. Burgwin. 1985. Paleo‐archaeological and historical

records of selected Pennsylvania mammals. Zouhar, K. 2001. Cirsium arvense. Fire Effects Annals of the Carnegie Museum 54: 77‐188. Information System [online]. U.S. Department of Agriculture, Forest Service, Rocky Woods, A. J., J. M. Omernik and D. D. Brown. Mountain Research Station, Fire Sciences 1999. Level III and IV Ecoregions of Delaware, Laboratory, Missoula, Montana. Maryland, Pennsylvania, Virginia, and West (www.fs.fed.us/database/feis/plants/shrub/ Virginia. U. S. Environmental Protection cirarv/introductory.html) Agency, National Health and Environmental Effects Research Laboratory, Corvallis, Zouhar, K. 2008. Berberis thunbergii. Fire Oregon. 56 pp. (ftp.epa.gov/wed/ecoregions/ Effects Information System [online]. U.S. reg3/reg3_eco_desc.doc; accessed 2008‐10‐ Department of Agriculture, Forest Service, 21) Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, Montana. Zimov, S. A., V. I. Chuprynin, A. P. Oreshko, F. S. (www.fs.fed.us/database/feis/plants/shrub/ Chapin, III, J. F. Reynolds and M. C. Chapin. berthu/introductory.html) 1995. Steppe‐tundra transition: a herbivore‐ driven biome shift at the end of the Pleist– ocene. American Naturalist 146: 765‐794.

Acknowledgments

We owe our sincere appreciation to those who Dr. Larry Klotz (botanist, Professor Emeritus, contributed in substantial ways to the Shippensburg University) information and ideas contained in this Betsy Leppo (Invertebrate Zoologist, document: Pennsylvania Natural Heritage Program) Gary Gimbert, Darin Groff, Roger Nichols, Dr. Dr. José‐Luis Machado (ecologist, Associate Jim Thorne, Scott Wendle (Natural Lands Trust) Professor, Swarthmore College) Tony Davis (Senior Ecologist, Pennsylvania Caron O’Neil (Senior Geologic Scientist, Natural Heritage Program) Pennsylvania Geological Survey) Janet Ebert and Jack Holt (botanical inventory Dr. Ann Rhoads (Senior Botanist, Pennsylvania consultants) Flora Project) Greg Edinger (Chief Ecologist, New York Dr. Dale Schweitzer (Terrestrial Invertebrate Natural Heritage Program; formerly Ecology Zoologist, NatureServe) Research Assistant, Pennsylvania Natural Heritage Program) Dr. Jeff Walck (botanist, Professor, Middle Tennessee State University) Liz Haegele (Urban Forestry Manager, Pennsylvania Horticultural Society; formerly Dr. Al Wheeler (entomologist, Adjunct master’s student in Environmental Studies, Professor, Clemson University) University of Pennsylvania)

100

Glossary

Note: Terms in italics are defined elsewhere in the glossary. adaptive management: Carrying out a set of other than H+ and Al3+. (See also cation land or wildlife management actions including exchange activity.) alternative methods, periodically monitoring biennial (plant): Usually completes its entire the results by collecting quantitative data, life cycle, seed to seed, in two years. reconsidering the methods and comparing alternatives in light of those results, and biological diversity (or biodiversity): Variety adjusting the next round of implementation of life forms at all scales—genomes and locally accordingly. Alternative methods are compared adapted populations within species; species with each other or with unmanaged controls within patches, communities, landscapes and using principles of the scientific method but as a regions; habitat structure within patches and routine part of management, with less cost (and communities; patch types within communities less stringent standards) than scientific and landscapes; community types within experiments. landscapes and regions, and ecoregions within the biosphere. (See also habitat diversity, patch adsorption: Attraction of ions or compounds to diversity, species diversity, structural diversity.) the surface of a solid. The soil particles on which adsorption (and release) of essential browser: Herbivore that subsists mainly by plant nutrients and other ions occurs (the browsing. adsorption complex) are mainly clays and browsing: Eating woody plants. decomposed organic matter. cation exchange activity (of soil): Adsorption angular flag: See flag. and release of cations (positively charged ions), annual (plant): Usually completes its entire life including acidity cations (H+, Al3+) and base cycle, seed to seed, in one year. cations, some of which are essential nutrients for plants (including Ca2+, Mg2+, K+). (See also argillic horizon (of soil): Mineral soil layer base saturation.) characterized by the illuvial accumulation of clay particles of layered crystalline silicon channer: Thin, flat rock fragment up to 6 oxides with negative electrical charge. Illuvial inches in length. A subangular channer is one refers to the process of material being washed with a shape characterized by neither sharp from an overlying horizon, precipitating from angles nor smooth rounding but something in solution and accumulating in a distinct layer. between. The presence or absence of an argillic horizon channery (of soil): Stony with channers. is used as a diagnostic characteristic in classifying soils. community: 1. Group of interacting plants, animals, fungi and other organisms that is fairly arthropod: Animal in the phylum Arthropoda, consistent in species composition and relative which includes insects, arachnids (spiders, abundance in similar environments throughout mites, ticks, daddy‐longlegs), myriapods a region; also called community type. 2. Specific (millipedes, centipedes) and crustaceans occurrence of such a group occupying an area (pillbugs, woodlice, crayfish, water‐fleas, within a landscape. (See also ecosystem.) fishlice, copepods). Arthropods, mainly insects on land and crustaceans in freshwater, typically community structure: See structure. account for the great majority of animal species control (in research or adaptive management): and animal biomass in a given area of land, 1. Separating the effects of a treatment under stream or lake. investigation from the effects of everything base saturation (of soil): Extent to which the else. 2. Untreated group of subjects or plots on adsorption complex of a soil is saturated with which the same data are collected as on exchangeable cations (positively charged ions) subjects or plots that receive a treatment, in

101

order to separate the effects of the treatment ecological community: See community. from the effects of everything else. ecological integrity: Ability of an ecosystem to cool‐season grass: Grass species that has support and maintain a community of photosynthetic machinery like most plants, a organisms with species composition, diversity system called C3 for short after the three‐ and functional organization comparable to carbon molecule that is the first product of those with the smallest degree of post‐ photosynthesis. Cool‐season grasses usually European‐settlement human influence. “An flower and fruit in spring or early summer and ecological system or species has integrity … grow best during spring and fall. (See also when its dominant ecological characteristics warm‐season grass.) (e.g., elements of composition, structure, function and ecological processes) occur within dbh: Diameter (of a tree trunk) at breast height their natural ranges of variation and can (standardized in the U.S. as 1.4 m or 4 feet 7 withstand and recover from most perturbations inches). imposed by natural environmental dynamics or disturbance: Relatively discrete event in time human disruptions.”1 Sometimes called that changes resources or the physical ecosystem “health” or the quality of being environment and typically reduces one or more “natural.” populations in the affected area, opening up ecological resilience: 1. “Ability of a[n space for colonization by the same or different eco]system to absorb disturbance and still species. The spatial scale of disturbances is retain its basic function and structure.”2 2. The highly variable, from a small patch to a region. speed at which an ecosystem returns to its disturbance frequency: Mean number of former state after it has been displaced from disturbance per time period for a particular that state by a disturbance. 3. The amount of area of land. The inverse of disturbance return disturbance required to push an ecosystem interval. over a threshold onto a successional pathway leading to different persistent state. disturbance intensity: Cumulative energy of a disturbance event (e.g., heat released by a fire). ecoregion: A geographically defined area in (Compare disturbance severity.) which ecosystems show a consistent pattern of common traits in terms of their geology, disturbance return interval: Mean time physiography, vegetation, climate, hydrology, between disturbances for a particular area of terrestrial and aquatic fauna, and soils. land. The inverse of disturbance frequency. Classification is hierarchical (e.g., the Piedmont disturbance severity: Impact of a disturbance Uplands are part of the Northern Piedmont, on an ecosystem and its constituents, including which lies within the Southeastern U.S.A. Plains, organisms, resources and the physical which are part of the Eastern Temperate environment. Often expressed in terms of Forests3). amount of mortality or species turnover. ecosystem: A community and its physical (Compare disturbance intensity.) environment. diversity: See biological diversity, habitat ecotonal: Pertaining to or located in an diversity, patch diversity, species diversity, ecotone. structural diversity. ecotone: Transition zone between two dominance: Extent to which one or a few dissimilar ecological communities. Often species dominate a community, i.e., have a applied to a forest‐grassland edge, including the majority share of total ecosystem biomass or area of forest subject to strong grassland cover. The inverse of evenness. influences (more light at ground level, higher duff: The organic (O) soil horizons considered heat, lower humidity) and the adjacent area of as a unit. Not a soil science term but often used in reference to fire behavior (e.g., proportions or quantities of duff consumed by fires burning 1 Eckert (2009): p. 2 under different soil moisture conditions). 2 Walker and Salt (2006): p. 1 3 Commission for Environmental Cooperation (2006)

102

grassland subject to strong forest influences graminoid: Grass or grass‐like plant such as a (more shade, more seed deposition by perching sedge or a rush. (See also forb.) birds, larger organic matter accumulation on grassland: Area dominated by herbaceous the ground and in soil from shed leaves and plants with more than 50% cover by grasses branches of trees, shrubs and lianas). that is uncultivated and has soils that are not endemic: Exhibiting endemism saturated year‐round. Includes prairie and grass‐dominated savanna. (See also meadow.) endemism (of a species): Restricted in range to a specific region or a geographically limited grazer: Herbivore that subsists mainly by ecosystem. grazing. Some grazers (e.g., bison) eat mainly grasses; others (e.g., white‐tailed deer, which evenness: Measure of how similar in are also browsers) eat mainly forbs. abundance co‐occurring species are within a patch or community. The inverse of dominance. grazing: Eating herbaceous plants. (See also One component of species diversity. (Compare browsing.) richness; see also biological diversity.) growth form: Classification of plants by size, fire frequency: See disturbance frequency. shape, longevity and mode of overwintering. The main distinction is herbaceous (dies back fire intensity: See disturbance intensity. to the ground in winter) versus woody (bears fire return interval: See disturbance return overwintering buds above the ground). Woody interval. plants are grouped into trees, shrubs, woody vines (lianas) or creepers; they may be fire severity: See disturbance severity. deciduous or evergreen. Herbaceous plants are flag: Thin, flat rock fragment 6–15 inches in grouped by longevity into annuals, biennials, length. An angular flag is one with a shape short‐lived perennials or long‐lived perennials; characterized by sharp angles. by shape into forbs or graminoids; and by posture into self‐standing, prostrate or forb: Herbaceous vascular plant that is not a climbing (herbaceous vines). grass or a grass‐like plant such as a sedge or a rush. Most forbs are wildflowers, although habitat: Place where a plant, animal or other herbaceous plants that have no flowers such as organism lives. Defined relative to an individual ferns are often included. (See also graminoid.) species or a group of similar species. forest: Area with 60% to 100% tree cover. (See habitat diversity: Measure of the difference in also woodland and savanna.) species composition, or turnover, among places—usually patches within a community or frequency (of fire or other disturbance): See communities within a landscape. (See also disturbance frequency. biological diversity and patch diversity.) friable (of soil): Easily crumbled. herbaceous (plant): Having no woody parts functional group: Subset of species in a aboveground. The stems of herbaceous plants community whose members are similar by one in the temperate zone die back to the ground or more meaningful criteria (e.g., morphology, surface in winter. (See growth form.) environmental response, role in ecosystem herbivore: Animal species that subsists on function, trophic level or taxonomic plant foods. relatedness). Examples in serpentine barrens include perennial warm‐season grasses, herbivory: Eating plant parts. (See browsing nonnative plants, oaks, butterflies or birds. and grazing.) gradient: 1. Slope (i.e., change in elevation horizon (of soil): See soil horizon. across an area of land). 2. Gradual change humus: Dark‐colored organic particles in soil across an area of land in an environmental that are among the end‐products of microbial factor that affects organisms (e.g., temperature, decomposition of plant and animal residues. sunlight, soil moisture, soil depth, soil nutrient availability). index (in research or monitoring): A relative measurement substituting for an absolute 103

quantity that is infeasible to measure, used to mapping unit: A polygon on a map or digital estimate trends over time (e.g., year‐to‐year map layer identified as belonging to a category trends in the number of individuals of an of land (e.g., grassland), usually within a set of animal species captured by a particular method related categories (e.g., vegetation type). (See in a standard length of time at a fixed location, also minimum mapping unit.) taken to indicate actual population trends of meadow: Area dominated by herbaceous that species). plants with more than 50% cover by forbs that indicator: See metric. is uncultivated and has soils that are not saturated year‐round. (See also grassland.) integrity: See ecological integrity. mesic: 1. (of plants or plant communities) intensity (of fire or other disturbance): See Intermediate in habitat affinity between hydric disturbance intensity. (wetland) and xeric (dry upland). 2. (of soils) introgressive hybrid: Organism whose Formed in a temperate‐zone climate with genome is mostly of one species but with a seasonally strongly fluctuating temperature smaller part from another, a condition averaging over the entire year between produced by repeated backcrossing of hybrid 8°C/47°F and 15°C/59°F. individuals with just one of the parent species. metapopulation: Geographically clustered invasive: Describes a nonnative plant, animal group of localized populations that are or other organism that undergoes extreme genetically and dynamically connected by proliferation, partly resulting from a lack of occasional intermigration of individuals. Often coevolved parasites, predators, diseases and consists of multiple sources and sinks. other checks on population growth outside its metric: Measurable, quantitative attribute of native range. Invasive organisms typically specific ecosystem components (e.g., plants, disrupt ecosystems by killing off or crowding animals, water, soil, people) used to out native populations, changing key characterize, evaluate and communicate the environmental attributes such as resource condition of an ecosystem at a specific time or availability, soil conditions and fire regimes, or across a sequence of intervals. Also called starting a cascade effect by disrupting indicator. multispecies interactions. minimum mapping unit: The threshold labile (of minerals in soil or soil organic smallest size mapping unit chosen for matter): Readily made available to plants by classifying land on a particular map or digital microbial transformation or decomposition. map layer. landscape: Heterogeneous land area composed native: Describes a plant, animal, fungus or of multiple interacting ecosystems in patches or other organism spontaneously inhabiting a blending together across gradients, each usually given region without having been introduced repeated in similar form throughout. there deliberately or inadvertently by human liana: Woody vine (e.g., summer grape and activity. In regions in the Americas, often taken common greenbrier, both native to the to mean species present at the time of first Northern Piedmont; Japanese honeysuckle and European contact, irrespective of whether they Oriental bittersweet, both nonnative in North might have been introduced from other regions America). by human action before then. Synonymous with indigenous. litter: Layer of undecomposed and little‐ decomposed fallen leaves, bark, wood and nonnative: Describes a plant, animal, fungus or other organic debris on the soil surface; also other organism inhabiting a given region by called the soil Oa soil horizon. (See also duff.) virtue of having been introduced, either deliberately or inadvertently, by human macronutrient: Chemical element required in activity. Synonymous with exotic and relatively large quantities for plant growth; introduced. A minority of nonnative species usually refers to nitrogen, phosphorus and become invasive. potassium (“NPK”).

104

parent material (of soils): The bedrock or recalcitrant (of organic matter in or on top of other underlying geological formation from soil): Resistant to decomposition. which the components of a soil are weathered. refugia: Plural of refugium. patch: Relatively discrete area within a refugium: Small, isolated area that has escaped community or ecosystem that is different in changes undergone by the surrounding area, some significant way from its surroundings, allowing the survival of plants and animals usually consisting of, or reflected in, differences from an earlier period. in plant species composition. replicates (in research or adaptive patch diversity: Variety of patch types within a management): Multiple subjects or community or ecosystem. (See also biological environmentally similar plots receiving the diversity and habitat diversity.) same treatment (or lack of treatment; see ped: A natural unit of soil structure such as a control). crumb or granule. replication (in research or adaptive perennial (plant): Typically has a lifespan of management): Use of replicates in the scientific three to many years. Usually applied to method. herbaceous plants. research plot: See plot. phenology: Seasonal timing of events in the life resilience: See ecological resilience. cycle of a plant, animal or other organism. return interval (of fire or other disturbance): phylogenetic: Pertaining to the evolutionary See disturbance return interval. history of a group of organisms, i.e., the relationships of groups of organisms to one rhizomatous (of plants): Spreading by another by descent from common ancestors. rhizomes—underground runners consisting of (See also taxon.) horizontal roots that send up shoots from tips or nodes. (See also stoloniferous.) phytometer: Living plant or group of plants on which selected attributes are measured as richness (of species): Number of species metrics of ecosystem condition or dynamics. present in a given area (e.g., quadrat, research Their use in research and monitoring is based plot, patch, community, landscape or region). on the idea that responses of plants integrate a One component of species diversity. (Compare multitude of physical, chemical and other evenness; see also biological diversity.) environmental factors and their complex savanna: Grassland with scattered trees or tall interactions; thus, when measured at regular shrubs making up between 10% and 25% of intervals they better reflect ecosystem the total vegetation cover. May also refer to condition and are more predictive of trends— meadow or low shrubland with 10% to 25% often with less effort—than direct tree or tall shrub cover. (See also forest and measurements of abiotic factors, whose woodland.) interactive effects on ecosystem components are poorly understood. scientific method: Self‐correcting method of research in which a problem is identified, plot (in research or adaptive management): The relevant data are gathered, a hypothesis is fundamental unit of replication; unit of land on formulated from the data, the hypothesis is which a treatment or combination of empirically tested by experiment, and the treatments is applied (trial plot) or not applied, results are used to verify, refute or modify the for comparison (control plot). (See also hypothesis. quadrat.) serpentine soil syndrome: Unusual soil prairie: Expansive grassland with less than mineral conditions affecting plants growing in 10% tree cover. (See also savanna.) soils weathered from serpentinite, in particular quadrat: Small area of land, often square, extremely high magnesium and nickel content rectangular or circular, on which ecological and extremely low calcium content. data are collected; often a subsample within a larger research or adaptive management plot. 105

severity (of fire or other disturbance): See ° C—partly weathered parent material disturbance severity. between B horizon and underlying unweathered parent material shrubland: Area dominated by shrubs. Usually applied to communities that persist for source: Localized population (and its habitat) relatively long periods of time (transient shrub‐ with a consistently positive growth rate, i.e., the dominated successional stages are often called birth rate is higher than the death rate and thickets). population stability occurs only if the emigration rate balances the surplus of births sink: Localized population (and its habitat) over deaths. Occurs in large areas of with a consistently negative growth rate, i.e., contiguous, high‐quality habitat. (See also sink the death rate is higher than the birth rate and and metapopulation.) continued existence depends on immigration. May nonetheless be important to help sustain species diversity: Richness and evenness of high overall population numbers and genetic species in a given area. (See also biological diversity in a metapopulation. Occurs in smaller diversity.) or lower‐quality habitat areas. (See also species dominance: See dominance. source.) species evenness: See evenness. soil horizon: A soil layer roughly parallel to the ground surface differentiated from other layers species of special conservation concern: Its by color, texture, organic matter content, continued existence in all or a part of its native mineral content and other characteristics. range is known to be imperiled, judged to be at risk of becoming imperiled, or undergoing soil profile: Sequence of soil horizons in a given sustained or rapid decline. In Pennsylvania, place. Profiles of soils in the Piedmont Uplands vascular plants, mammals, birds, snakes, generally include some subset of the following lizards, turtles, amphibians, freshwater horizons, listed in order from the uppermost mussels, Lepidoptera (butterflies and moths), downward: Odonata (dragonflies and damselflies) and a • O horizons—surface layers of organic matter few species belonging to other groups of ° Oa—mostly undecomposed fallen leaves, organisms are systematically tracked and an bark, wood and other organic debris (also official list of species of special concern is called litter) updated yearly by the Pennsylvania Biological ° Oi—partly decomposed fibrous matter Survey, Pennsylvania Natural Heritage Program including small but recognizable fragments and state natural resource agencies. of plant parts species richness: See richness. Oe—more‐fully decomposed, finely ° stoloniferous (of plants): Spreading by granular natural compost (rich in humus) stolons—aboveground runners consisting of • Mineral soil horizons—mainly minerals horizontal stems that send up shoots from tips weathered from parent material or nodes. (See also rhizomatous.) A—dark‐colored mineral layer ° stratified random sampling: Collecting data immediately beneath O horizon with high on research subjects or locations picked using a content of humus accumulated from above randomization procedure from a number of ° Ap—plow layer, consisting of a mixture of subpopulations or categories. “Stratified” refers two or more former soil layers (O, A, E or B to the different subpopulations or categories horizons) to the depth of plowing (“strata”) from which subjects or locations are ° E—light‐colored mineral layer leached of chosen. Stratifying insures that roughly equal silicate clays, iron or aluminum, consisting numbers of subjects or locations are picked as mainly of sand and silt targets of data collection from each ° B—layer beneath O, A or E horizon marked subpopulation or category so that valid by the accumulation of silicate clays, iron comparisons can be made. or aluminum

106

structural diversity: Variety of community vascular plant: Plant in which fluids circulate structure present within a defined area. (See via conducting vessels—xylem and phloem. All also biological diversity.) true plants are vascular plants except mosses, liverworts, hornworts and green algae (other structure (of a community): Vertical layering algae and lichens are not classified as plants). and horizontal arrangement of plants of Includes all trees, shrubs, vines, wildflowers, different sizes and growth forms, the extent of grasses, rushes, sedges, ferns, clubmosses and vegetation cover, canopy closure and bare spikemosses (the latter are not true mosses). ground, the type and abundance of dead plants or plant parts, and the amounts and types of warm‐season grass: Grass species that has a decomposing plant material. specialized photosynthetic system called C4 for short, after the four‐carbon molecule that is the subangular channer: See channer. first product of photosynthesis. It works in a succession: Non‐seasonal, directional and manner similar to a turbocharger in a car continuous pattern of colonization, relative engine, delivering carbon dioxide much more dominance and extinction on a site by efficiently (using far less water) to the sunlight‐ populations, usually set in motion by powered parts of the plants’ cells that combine disturbance. CO2 with H2O to produce sugars, fueling growth. Warm‐season grasses usually flower and fruit taxon (plural = taxa): Unit of phylogenetic in late summer or fall and grow mainly in the classification of an organism at any level of the heat of summer. The C system enables warm‐ classification hierarchy, including (but not 4 season grasses to continue photosynthesizing limited to) domain, kingdom, phylum, class, and growing when most plants are forced by order, family, genus, species, subspecies and heat or dry soil conditions to shut down. (See variety. also cool‐season grass.) treatment (in research or adaptive woodland: Area with 25% to 60% tree cover. management): Manipulation applied to a set of (See also forest and savanna.) replicates to test scientific hypotheses or alternative methods of management. woods: Informal umbrella term for woodland and forest.

107

108

Appendix A. Interpretation of Rank and Status Codes for Species of Special Conservation Concern

Table A‐1. Explanation of global and state rarity ranks used in Tables 5 and 6 (pp. 35–37) and Appendix C (pp. 145–148). Adapted from NatureServe and Pennsylvania Natural Heritage Program. G2 Imperiled globally because of rarity or because of some factor(s) making it very vulnerable to extinction. Typically 6–20 occurrences or few remaining individuals (1,000– 3,000). G3 Vulnerable globally because very rare and local throughout its range, or found only in a restricted range (even if abundant at some locations), or because of other factors making it vulnerable to extinction. Typically 21–100 occurrences or 3,000–10,000 individuals in the species’ total range. G4 Uncommon but not rare globally, and usually widespread. Possibly cause for long‐term concern. Typically more than 100 occurrences and more than 10,000 individuals in the species’ total range. G5 Secure globally. Common, typically widespread and abundant, with considerably more than 100 occurrences and 10,000 individuals in the species’ total range. G#G# Numeric range (e.g., G3G4) used to indicate uncertainty about global status. More information is needed. T# Numeric global rank (e.g., T4) reflecting the rarity of a subspecies that differs from that of the species as a whole. ? Indicates a high level of uncertainty. More information is needed. S1 Critically imperiled in the state because of extreme rarity or because of some factor(s) making it extremely vulnerable to extirpation from the state. Typically 5 or fewer occurrences or very few remaining individuals or acres within the state. S2 Imperiled in the state because of rarity or because of some factor(s) making it very vulnerable to extirpation from the state. Typically 6–20 occurrences or few remaining individuals or acres within the state. S3 Vulnerable in the state because rare, or found only in a restricted range (even if abundant at some locations), or because of other factors making it vulnerable to extirpation. Typically 21–100 occurrences within the state. S#S# Numeric range (e.g., S2S3) used to indicate uncertainty about status in the state. More information is needed. SH Occurred historically in the state, not verified in the past 20 years, but suspected to be still extant. A rank of SH applies without a 20‐year delay after the most recent documented occurrence if the only known occurrences in the state were destroyed or subjected to intensive searching but not found. A rank of SH typically changes to S1 upon verification of an extant occurrence. SNR Not yet ranked. SU Currently unrankable due to lack of information or due to substantially conflicting information about status or trends.

109

Table A‐2. Explanation of Pennsylvania Biological Survey (PABS) status codes used in Tables 5 and 6 (pp. 35–37), subsection 3.1.1 (p. 41‐42) and Table 7 (pp. 50–59). Adapted from Pennsylvania Biological Survey. PE Endangered in Pennsylvania. Native species in imminent danger of extinction or extirpation throughout their range in Pennsylvania if the deleterious factors affecting them continue to operate. PT Threatened in Pennsylvania. Native species that may become endangered within the foreseeable future throughout their range in Pennsylvania unless the casual factors affecting the organism are abated. PR Rare in Pennsylvania. Uncommon native species classified as disjunct, limit of range, endemic or restricted that do not qualify for PE or PT status. Disjunct = significantly separated from the species’ main area of distribution. Limit of range = at or near the periphery of the species’ natural distribution. Endemic = confined throughout its range to a specialized habitat. Restricted = in its Pennsylvania range, confined to a specialized habitat or set of habitats occurring infrequently in the state. SP Special population. Unique occurrence deserving protection that does not fall into any of the other categories. Native species that is relatively scarce and significant for reasons such as ecological importance, recent decline, vulnerability, role as host for imperiled animal species, or occurrence in Pennsylvania comprising a high proportion (~ 10% or more) of the species’ entire population. TU Status in Pennsylvania tentatively undetermined. Native species believed to be in danger of population decline, but which cannot presently be included within another classification due to taxonomic uncertainties, limited evidence in historical records, or insufficient field data. TU is a temporary classification until the needed information can be gathered.

Table A‐3. Explanation of Pennsylvania conservation tier codes listed in parentheses under state status in Appendix C (pp. 145–148). From Rawlins (2007: pp. 16–19). 1 Immediate concern. … species that are most at risk and/or are experiencing the most dramatic declines across their range. … include[s] globally rare or imperiled species, nationally rare or imperiled species, as well as those species in Pennsylvania and/or neighboring states that are declining to the point that some may require federal listing in the future. 2 High‐level concern. … nationally and/or regionally significant species that are vulnerable in Pennsylvania. … include[s] species with localized and vulnerable populations, species with limited dispersal, species with fragmented or isolated populations, and some species in need of additional research to determine status. 4 Pennsylvania vulnerable. … species that for reasons of rarity are ranked as being of conservation concern in Pennsylvania, but are not currently at risk globally or in the region. If rarity is known to result from sharp decline in abundance or distribution in the Commonwealth but not elsewhere, then the species in question are certainly of conservation concern, but at a lower priority than those that also are at known risk globally (Tier 1 and to some extent, Tier 2 species).

110

Appendix B. Vascular Plants of the Unionville Barrens

KEY TO SYMBOLS AND TYPEFACES IN TABLE B‐1 (begins on next page)

Nonnative species (most originating in Eurasia) are indicated by small, boldface, sans serif type.

2010 PABS (Pennsylvania Biological Survey) status: PE endangered in the state PT threatened in the state PR rare in the state SP special population deserving protection that does not fall into another category TU tentatively believed to be declining or imperiled but status undetermined due to insufficient data; under study or needing study

Growth form: HA herbaceous annual VA herbaceous annual vine HB herbaceous biennial HP herbaceous perennial VP herbaceous perennial vine SD deciduous shrub VW woody vine TD/TE deciduous/evergreen tree

C3 or C4 (grasses only):

C3 cool‐season grass

C4 warm‐season grass

Grassland habitat: S1E restricted throughout species’ range (endemic) to serpentine grasslands S1 nearly or quite restricted to serpentine grasslands in southeastern Pennsylvania S2 found more often in serpentine grasslands than in other habitats in southeastern Pennsylvania S3 characteristic of serpentine grasslands but found no less often in other grassland habitats in southeastern Pennsylvania O found mainly in other grassland habitats in southeastern Pennsylvania

Extirpated (?): X historically documented in the Unionville Barrens but not seen in recent years; tentatively presumed extirpated, although small numbers might still be present and have eluded detection

111

112 (Key to symbols and typefaces—p. 111. Index to all names—p. 132.)

Table B‐1. List of the vascular plants of the Unionville Barrens. Sources: extant species—surveys by Janet Ebert and Jack Holt (2002–2003), Roger Latham (2003–2011), Philadelphia Botanical Club & Muhlenberg Botanical Society field trip (2010); “extirpated (?)” species—Pennell (1910–1912); herbarium records of Pennsylvania Flora Project, Morris Arboretum, University of Pennsylvania & Academy of Natural Sciences of Philadelphia.

HIGHER TAXON 2010 grass‐ Family PABS growth C3 / C4 land extirpa‐ Genus, species (& variety or subspecies) common name(s) status form (grasses) specialist ted (?) FERNS AND LYCOPODS Lycopodiaceae Diphasiastrum tristachyum (Pursh) Holub deep‐rooted running‐pine, deep‐root HP clubmoss Lycopodium obscurum L. flat‐branched ground‐pine HP Ophioglossaceae Botrychium dissectum Spreng. cut‐leaf grape‐fern HP Botrychium virginianum (L.) Sw. rattlesnake fern HP Osmundaceae Osmunda claytoniana L. interrupted fern HP Osmunda regalis L. royal fern HP S2 Polypodiaceae Asplenium platyneuron (L.) Britton, ebony spleenwort HP Stearns & Poggenb. Athyrium filix‐femina (L.) Roth ex Mert. southern lady‐fern HP Dennstaedtia punctilobula (Michx.) hay‐scented fern HP O T.Moore Deparia acrostichoides (Sw.) M.Kato silvery glade fern HP Dryopteris carthusiana (Vill.) H.P.Fuchs spinulose wood‐fern HP Dryopteris intermedia (Muhl.) A.Gray intermediate wood‐fern, evergreen HP wood‐fern, fancy fern Dryopteris marginalis (L.) A.Gray marginal wood‐fern HP Onoclea sensibilis L. sensitive fern HP

HIGHER TAXON 2010 grass‐ Family PABS growth C3 / C4 land extirpa‐ Genus, species (& variety or subspecies) common name(s) status form (grasses) specialist ted (?) Polypodium virginianum L. common polypody, rock polypody, HP rockcap Polystichum acrostichoides (Michx.) Christmas fern HP Schott Pteridium aquilinum (L.) Kuhn northern bracken fern HP O Thelypteris noveboracensis (L.) Nieuwl. New York fern HP Thelypteris palustris Schott marsh fern, eastern marsh fern HP O GYMNOSPERMS Cupressaceae Juniperus virginiana L. eastern red‐cedar TE S3 MAGNOLIIDS Aristolochiaceae Aristolochia serpentaria L. Virginia snakeroot HP Lauraceae Lindera benzoin (L.) Blume spicebush SD Sassafras albidum (Nutt.) Nees sassafras TD Magnoliaceae Liriodendron tulipifera L. tuliptree, yellow‐poplar TD EUDICOTS Amaranthaceae Chenopodium album L. lamb’s‐quarters HA Berberidaceae Berberis thunbergii DC Japanese barberry SD Podophyllum peltatum L. mayapple, mandrake HP

113 (Table continues on next page.) 114 (Key to symbols and typefaces—p. 111. Index to all names—p. 132.)

HIGHER TAXON 2010 grass‐ Family PABS growth C3 / C4 land extirpa‐ Genus, species (& variety or subspecies) common name(s) status form (grasses) specialist ted (?) Caryophyllaceae Arenaria serpyllifolia L. thyme‐leaf sandwort HA Cerastium nutans Raf. nodding chickweed HA Cerastium velutinum L. var. velutinum barrens chickweed SP HP S1 Dianthus armeria L. Deptford pink HB Minuartia michauxii (Fernald) Farw. rock sandwort, Michaux’s stitchwort SP HA HP S1 Myosoton aquaticum (L.) Moench giant chickweed, water mouse‐ear HP Silene stellata (L.) W.T.Aiton starry campion, widow’s‐frill HP O Stellaria media (L.) Vill. common chickweed HA Hamamelidaceae Hamamelis virginiana L. witch‐hazel SD Papaveraceae Sanguinaria canadensis L. bloodroot, red puccoon HP Phytolaccaceae Phytolacca americana L. pokeweed HP Platanaceae Platanus occidentalis L. American sycamore, buttonwood, TD American planetree Polygonaceae Persicaria longiseta (Bruijn) Kitagawa low smartweed, Oriental lady’s‐thumb HA Persicaria virginiana (L.) Gaertn. jumpseed HP Polygonum aviculare L. prostrate knotweed HA Polygonum tenue Michx. slender knotweed, pleat‐leaf knotweed HA S2 Rumex acetosella L. sheep sorrel, sourgrass HP Rumex obtusifolius L. bitter dock HP

HIGHER TAXON 2010 grass‐ Family PABS growth C3 / C4 land extirpa‐ Genus, species (& variety or subspecies) common name(s) status form (grasses) specialist ted (?) Portulacaceae Claytonia virginica L. spring‐beauty HP Phemeranthus teretifolius (Pursh) Raf. round‐leaf fameflower, quill fameflower PT HP S1 Ranunculaceae Clematis virginiana L. virgin’s‐bower, devil’s darning‐needles VP Ranunculus bulbosus L. bulbous buttercup, St. Anthony’s‐turnip HP Ranunculus recurvatus Poir. hooked crowfoot, blisterwort HP Thalictrum pubescens Pursh tall meadow‐rue, king‐of‐the‐meadow HP Saxifragaceae Heuchera americana L. American alum‐root HP Saxifraga virginiensis Michx. early saxifrage HP Vitaceae Parthenocissus quinquefolia (L.) Planch. Virginia‐creeper, woodbine VW Vitis aestivalis Michx. summer grape, pigeon grape VW X Vitis vulpina L. frost grape VW ROSIDS Geraniaceae Geranium maculatum L. wood geranium, spotted geranium HP Onagraceae Circaea canadensis (L.) Hill ssp. enchanter’s‐nightshade HP canadensis (L.) Aschers. & Magnus Oenothera fruticosa L. sundrops, narrow‐leaf evening‐ HP S3 primrose Oenothera perennis L. little evening‐primrose, sundrops HP O

115 (Table continues on next page.) 116 (Key to symbols and typefaces—p. 111. Index to all names—p. 132.)

HIGHER TAXON 2010 grass‐ Family PABS growth C3 / C4 land extirpa‐ Genus, species (& variety or subspecies) common name(s) status form (grasses) specialist ted (?) EUROSIDS Anacardiaceae Rhus copallina L. shining sumac, winged sumac, dwarf SD S3 sumac Toxicodendron radicans (L.) Kuntze poison‐ivy, eastern poison‐ivy VW Betulaceae Carpinus caroliniana Walter American hornbeam, ironwood TD Corylus americana Walter American filbert, American hazelnut SD Brassicaceae Alliaria petiolata (M.Bieb.) Cavara & Grande garlic mustard HB Arabis lyrata L. lyre‐leaf rockcress HB HP S2 Barbarea vulgaris R.Br. common wintercress, garden yellow rocket HB Cardamine hirsuta L. hairy bittercress HA Cardamine pensylvanica Muhl. ex Willd. Pennsylvania bittercress HP Lepidium campestre (L.) R.Br. fieldcress, field pepperweed HA HB Lepidium densiflorum Schrader wild pepper‐grass, common pepperweed HA HB Cannabaceae Celtis occidentalis L. common hackberry, sugarberry TD Celastraceae Celastrus orbiculatus Thunb. Oriental bittersweet VW Euonymus alatus (Thunb.) Siebold winged euonymous, burning‐bush SD Cistaceae Helianthemum bicknellii Fernald Bicknell’s hoary rockrose, hoary PE HP S2 frostweed

HIGHER TAXON 2010 grass‐ Family PABS growth C3 / C4 land extirpa‐ Genus, species (& variety or subspecies) common name(s) status form (grasses) specialist ted (?) Cucurbitaceae Sicyos angulatus L. bur cucumber, one‐seeded bur VA cucumber Elaeagnaceae Elaeagnus angustifolia L. Russian‐olive SD Elaeagnus umbellata Thunb. autumn‐olive SD Euphorbiaceae Acalypha rhomboidea Raf. common three‐seeded mercury HA Fabaceae Amphicarpaea bracteata (L.) Fernald American hog‐peanut VP VA Apios americana Medik. groundnut, wild bean VP Baptisia tinctoria (L.) Vent. wild indigo, horseflyweed HP Chamaecrista nictitans (L.) Moench wild sensitive‐plant, sensitive partridge HA O X pea Desmodium ciliare (Muhl. ex Willd.) DC. hairy small‐leaf tick‐trefoil, tick‐clover HP Desmodium marilandicum (L.) DC smooth small‐leaf tick‐trefoil, Maryland HP S3 tick‐clover Desmodium obtusum (Muhl. ex Willd.) DC. stiff tick‐trefoil TU HP X Desmodium paniculatum (L.) DC panicled‐leaf tick‐trefoil HP O X Lespedeza capitata Michx. round‐headed bush‐clover, roundhead HP S2 X lespedeza Lespedeza virginica (L.) Britton slender bush‐clover HP S2 Medicago lupulina L. black medic HA Melilotus alba Medik. white sweet‐clover HB HA Robinia pseudoacacia L. black locust TD Trifolium campestre Schreb. low hop‐clover, field clover HA Trifolium pratense L. red clover HP

117 (Table continues on next page.) 118 (Key to symbols and typefaces—p. 111. Index to all names—p. 132.)

HIGHER TAXON 2010 grass‐ Family PABS growth C3 / C4 land extirpa‐ Genus, species (& variety or subspecies) common name(s) status form (grasses) specialist ted (?) Fagaceae Castanea dentata (Marshall) Borkh. American chestnut TD Fagus grandifolia Ehrh. American beech TD Quercus alba L. white oak TD Quercus ×bushii Sarg. (Q. marilandica × Bush’s oak* TD S1 velutina)* Quercus coccinea Muenchh. scarlet oak TD Quercus marilandica Muenchh.* blackjack oak* TD S1 Quercus montana Willd. chestnut oak TD Quercus nigra L. water oak TD Quercus palustris Muenchh. pin oak TD Quercus prinoides Willd. dwarf chestnut oak SD S2 Quercus prinoides × alba Faxon oak TD X Quercus rubra L. northern red oak TD Quercus stellata Wangenh. post oak TD S2 Quercus velutina Lam. black oak TD Hypericaceae Hypericum punctatum Lam. spotted St. John’s‐wort HP Juglandaceae Carya glabra (P.Mill.) Sweet pignut hickory TD Juglans nigra L. black walnut TD Linaceae Linum virginianum L. slender yellow flax HP O X

* It is uncertain which taxon trees at the Unionville Barrens resembling Bush’s oak (Quercus ×bushii) or blackjack oak (Q. marilandica) actually belong to. Branching structure, bark appearance and growth habit are typical of blackjack oak but leaf morphology is atypical, more closely resembling that of black oak (Q. velutina), the other parent species of the hybrid Bush’s oak (see discussion under Species surveys, pp. 33–34).

HIGHER TAXON 2010 grass‐ Family PABS growth C3 / C4 land extirpa‐ Genus, species (& variety or subspecies) common name(s) status form (grasses) specialist ted (?) Moraceae Morus alba L. white mulberry TD Myricaceae Myrica pensylvanica Mirbel bayberry, northern bayberry SD Oxalidaceae Oxalis dillenii Jacq. ssp. filipes (Small) southern yellow wood‐sorrel, slender HP O G.Eiten yellow wood‐sorrel Polygalaceae Polygala verticillata L. whorled milkwort HA S3 Rhamnaceae Ceanothus americanus L. New Jersey tea SP SD S3 Rosaceae Agrimonia parviflora Aiton southern agrimony, harvestlice HP Agrimonia pubescens Wallr. downy agrimony, soft agrimony HP Amelanchier arborea (Michx.f.) Fernald common serviceberry, shadbush, TD juneberry Duchesnea indica (Andr.) Focke Indian strawberry HP Fragaria virginiana Duchesne wild strawberry, Virginia strawberry HP Geum canadense Jacq. white avens HP Malus coronaria (L.) Mill. sweet crabapple TD O X Malus sp. crabapple TD Potentilla canadensis L. dwarf cinquefoil HP S3 Prunus avium (L.) L. sweet cherry, bird cherry TD Prunus serotina Ehrh. black cherry, wild black cherry TD Pyrus communis L. common pear TD Rosa carolina L. pasture rose, Carolina rose SD S3 Rosa multiflora Thunb. ex Murray multiflora rose SD

119 (Table continues on next page.) 120 (Key to symbols and typefaces—p. 111. Index to all names—p. 132.)

HIGHER TAXON 2010 grass‐ Family PABS growth C3 / C4 land extirpa‐ Genus, species (& variety or subspecies) common name(s) status form (grasses) specialist ted (?) Rubus allegheniensis Porter common blackberry, Allegheny SD blackberry Rubus flagellaris Willd. prickly dewberry, northern dewberry VW Rubus occidentalis L. black raspberry, black‐cap SD Rubus pensilvanicus Poir. Pennsylvania blackberry SD O X Rubus phoenicolasius Maxim. wineberry, wine raspberry SD Spiraea latifolia (Aiton) Borkh. white meadowsweet SD S2 X Salicaceae Populus grandidentata Michx. bigtooth aspen TD Salix humilis Marshall var. humilis dwarf upland willow, sage willow, SD O X prairie willow Sapindaceae Acer platanoides L. Norway maple TD Acer pseudoplatanus L. sycamore maple TD Acer rubrum L. red maple TD Simaroubaceae Ailanthus altissima (P.Mill.) Swingle ailanthus, tree‐of‐heaven TD Urticaceae Boehmeria cylindrica (L.) Sw. false nettle, stingless nettle, smallspike HP false nettle Violaceae Viola macloskeyi F.E.Lloyd ssp. pallens sweet white violet, smooth white violet HP (Banks ex Ging.) M.S.Baker Viola sagittata Aiton arrow‐leaf violet HP S2 Viola sororia Willd. common blue violet HP O

HIGHER TAXON 2010 grass‐ Family PABS growth C3 / C4 land extirpa‐ Genus, species (& variety or subspecies) common name(s) status form (grasses) specialist ted (?) ASTERIDS Balsaminaceae Impatiens capensis Meerb. jewelweed, orange jewelweed, spotted HA touch‐me‐not Cornaceae Cornus florida L. flowering dogwood TD Ericaceae Chimaphila maculata (L.) Pursh pipsissewa, spotted wintergreen, HP striped prince’s‐pine Epigaea repens L. trailing‐arbutus SE Gaylussacia baccata (Wangenh) K.Koch black huckleberry SD Kalmia latifolia L. mountain‐laurel SE Monotropa uniflora L. Indian‐pipe HP Rhododendron periclymenoides (Michx.) pinxter‐flower, pink azalea SD Shinners Vaccinium pallidum Aiton lowbush blueberry SD Vaccinium stamineum L. deerberry SD Myrsinaceae Lysimachia ciliata L. fringed loosestrife HP Lysimachia quadrifolia L. whorled loosestrife, whorled yellow HP loosestrife Nyssaceae Nyssa sylvatica Marshall black‐gum, sour‐gum, tupelo TD Polemoniaceae Phlox subulata L. ssp. subulata moss phlox, moss‐pink HP S1

121 (Table continues on next page.) 122 (Key to symbols and typefaces—p. 111. Index to all names—p. 132.)

HIGHER TAXON 2010 grass‐ Family PABS growth C3 / C4 land extirpa‐ Genus, species (& variety or subspecies) common name(s) status form (grasses) specialist ted (?) EUASTERIDS Adoxaceae Sambucus canadensis L. American elder, American black SD elderberry Viburnum acerifolium L. maple‐leaf viburnum SD Viburnum dentatum L. southern arrow‐wood SD Viburnum lentago L. nannyberry, sheepberry SD Viburnum prunifolium L. black‐haw SD TD Viburnum setigerum Hance tea viburnum SD Apiaceae Angelica venenosa (Greenway) Fernald deadly angelica, hairy angelica HP S2 X Cicuta maculata L. var. maculata spotted water‐hemlock, beaver‐poison, HP musquash‐root, spotted cowbane Cryptotaenia canadensis (L.) DC honewort, wild‐chervil HP Daucus carota L. Queen Anne’s‐lace, wild carrot HB Osmorhiza longistylis (Torr.) DC anise‐root, long‐style sweet‐root HP Sanicula canadensis L. Canadian sanicle, Canadian black HB snakeroot Zizia aptera (A.Gray) Fernald golden‐alexander, meadow zizia HP O X Apocynaceae Apocynum cannabinum L. Indian hemp HP O Asclepias syriaca L. common milkweed HP Asclepias verticillata L. whorled milkweed HP S1 Asclepias viridiflora Raf. green milkweed HP S2 Aquifoliaceae Ilex opaca Aiton American holly PT TE Ilex verticillata (L.) A.Gray common winterberry, black‐alder SD

HIGHER TAXON 2010 grass‐ Family PABS growth C3 / C4 land extirpa‐ Genus, species (& variety or subspecies) common name(s) status form (grasses) specialist ted (?) Araliaceae Aralia nudicaulis L. wild sarsaparilla HP Asteraceae Achillea millefolium L. common yarrow, milfoil HP Ageratina altissima (L.) R.M.King & white‐snakeroot HP H.Robinson var. altissima Ageratina aromatica (L.) Spach small‐leaf white‐snakeroot PR HP S2 Ambrosia artemisiifolia L. common ragweed HA S3 Ambrosia trifida L. giant ragweed HA Antennaria neglecta Greene overlooked pussytoes, field pussytoes HP O Antennaria plantaginifolia (L.) Hook. plantain‐leaf pussytoes, woman’s HP S3 tobacco Arctium minus (Hill) Bernh. woodland burdock, lesser burdock HB Carduus nutans L. nodding thistle, musk thistle HB Cichorium intybus L. blue chicory, blue‐sailors HP Cirsium arvense (L.) Scop. Canada thistle HP Cirsium muticum Michx. swamp thistle HB S2 Cirsium pumilum (Nutt.) Spreng. pasture thistle HB Conyza canadensis (L.) Cronquist fleabane, Canadian horseweed HA Erigeron annuus (L.) Pers. eastern daisy fleabane HA HB Erigeron philadelphicus L. Philadelphia fleabane, daisy fleabane HP Eupatorium perfoliatum L. common boneset HP O X Eurybia divaricata (L.) Nesom white wood aster HP Euthamia graminifolia (L.) Nutt. grass‐leaf goldenrod, flat‐top goldenrod HP O Helianthus giganteus L. swamp sunflower, giant sunflower HP O Hieracium venosum L. rattlesnake‐weed HP Lactuca canadensis L. wild lettuce, Canada lettuce HA HB O

123 (Table continues on next page.) 124 (Key to symbols and typefaces—p. 111. Index to all names—p. 132.)

HIGHER TAXON 2010 grass‐ Family PABS growth C3 / C4 land extirpa‐ Genus, species (& variety or subspecies) common name(s) status form (grasses) specialist ted (?) Lactuca serriola L. prickly lettuce HA HB Leucanthemum vulgare Lam. ox‐eye daisy HP Packera anonyma (A.W.Wood) Small’s ragwort, Appalachian groundsel PR HP S2 W.A.Weber & A.Love Prenanthes altissima L. tall rattlesnake‐root HP Prenanthes serpentaria Pursh lion’s‐foot, cankerweed PT HP S2 X Pseudognaphalium obtusifolium (L.) fragrant cudweed, rabbit‐tobacco HA HB Hilliard & B.L.Burtt. Rudbeckia hirta L. black‐eyed‐susan HB HP Rudbeckia laciniata L. cutleaf coneflower, green‐headed HP coneflower Senecio vulgaris L. common groundsel, old‐man‐in‐the‐spring HA Sericocarpus asteroides (L.) Britton, white‐topped aster HP O Stearns & Poggenb. Solidago canadensis L. Canada goldenrod HP O Solidago juncea Aiton early goldenrod HP O Solidago nemoralis Aiton gray goldenrod HP S3 Solidago rugosa P.Mill. wrinkle‐leaf goldenrod HP S3 Sonchus asper (L.) Hill spiny‐leaf sow‐thistle HA Symphyotrichum cordifolium (L.) Nesom blue wood aster HP Symphyotrichum depauperatum serpentine aster PT HP S1E (Fernald) Nesom Symphyotrichum ericoides (L.) Nesom white heath aster PT HP S3 X Symphyotrichum laeve (L.) A.Love & smooth blue aster HP S2 X D.Love var. laeve Symphyotrichum lateriflorum (L.) A.Love calico aster HP S3 & D.Love Symphyotrichum pilosum (Willd.) Nesom heath aster, Pringle’s aster HP S3

HIGHER TAXON 2010 grass‐ Family PABS growth C3 / C4 land extirpa‐ Genus, species (& variety or subspecies) common name(s) status form (grasses) specialist ted (?) Taraxacum officinale F.H.Wigg. common dandelion HP Tragopogon dubius Scop. yellow goatsbreard, yellow salsify HB Vernonia noveboracensis (L.) Michx. New York ironweed HP Boraginaceae Hackelia virginiana (L.) I.M.Johnst. beggar’s‐lice, stickseed HB Campanulaceae Lobelia inflata L. Indian‐tobacco HA Lobelia puberula Michx. downy lobelia PE HP O X Lobelia spicata Lam. var. spicata spiked lobelia HP S3 Caprifoliaceae Lonicera japonica Thunb. Japanese honeysuckle VW Lonicera maackii (Rupr.) Maxim. Amur honeysuckle SD Lonicera morrowii A.Gray Morrow’s honeysuckle SD Convolvulaceae Calystegia spithamaea (L.) Pursh low bindweed VP Gentianaceae Sabatia angularis (L.) Pursh common marsh‐pink, rose‐pink HA S2 Lamiaceae Clinopodium vulgare L. wild basil HP Lycopus virginicus L. bugleweed, water‐horehound, Virginia HP water‐horehound Perilla frutescens (L.) Britton perilla, beefsteak‐plant HA Prunella vulgaris L. ssp. lanceolata heal‐all, self‐heal, lance self‐heal HP O (Barton) Hulten Pycnanthemum tenuifolium Schrad. narrow‐leaf mountain‐mint HP S3 Pycnanthemum virginianum (L.) Durand Virginia mountain‐mint HP O & Jacks. ex B.L.Rob. & Fernald

125 (Table continues on next page.) 126 (Key to symbols and typefaces—p. 111. Index to all names—p. 132.)

HIGHER TAXON 2010 grass‐ Family PABS growth C3 / C4 land extirpa‐ Genus, species (& variety or subspecies) common name(s) status form (grasses) specialist ted (?) Scutellaria integrifolia L. hyssop skullcup, helmet‐flower HP O Trichostema dichotomum L. blue‐curls, forked bluecurls HA O Oleaceae Fraxinus americana L. var. americana white ash TD Ligustrum obtusifolium Siebold & Zucc. border privet, obtuse‐leaf privet SD Orobanchaceae Aureolaria pedicularia (L.) Raf. cut‐leaf false‐foxglove, fernleaf yellow HA O X false‐foxglove Epifagus virginiana (L.) W.P.C.Barton beechdrops HA Plantaginaceae Callitriche terrestris Raf. emend. Torr. water‐starwort, terrestrial water‐ HA starwort Chelone glabra L. white turtlehead HP Plantago lanceolata L. English plantain, ribgrass, narrow‐leaf HP HA plantain Plantago rugelii Decne. Rugel’s plantain, broad‐leaf plaintain, HP black‐seed plantain Veronica arvensis L. corn speedwell HA Veronica persica Poir. bird’s‐eye speedwell HA Rubiaceae Galium aparine L. bedstraw, cleavers, goosegrass, HA stickywilly Galium circaezans Michx. wild licorice, licorice bedstraw HP Galium mollugo L. white bedstraw, wild madder, false baby’s‐ HP breath Galium pilosum Aiton hairy bedstraw, cleavers HP O Galium triflorum Michx. sweet‐scented bedstraw, fragrant HP bedstraw

HIGHER TAXON 2010 grass‐ Family PABS growth C3 / C4 land extirpa‐ Genus, species (& variety or subspecies) common name(s) status form (grasses) specialist ted (?) Houstonia caerulea L. bluets, Quaker‐ladies, azure bluet HP S3 Mitchella repens L. partridge‐berry HP Scrophulariaceae Verbascum blattaria L. moth mullein HB Verbascum thapsus L. common mullein, flannel‐plant HB Solanaceae Physalis subglabrata Mack. & Bush long‐leaf ground‐cherry HP Solanum carolinense L. horse‐nettle HP O Solanum nigrum L. black nightshade HA Verbenaceae Verbena urticifolia L. white vervain HA HP NON‐COMMELINID MONOCOTS Alliaceae Allium vineale L. field garlic, scallions HP Araceae Arisaema triphyllum (L.) Schott jack‐in‐the‐pulpit HP Symplocarpus foetidus (L.) Salisb. ex skunk‐cabbage HP W.P.C.Barton Colchicaceae Uvularia perfoliata L. bellwort, perfoliate bellwort HP Hyacinthaceae Ornithogalum umbellatum L. star‐of‐Bethlehem, sleepy‐dick HP Iridaceae Sisyrinchium angustifolium P.Mill. narrow‐leaf blue‐eyed‐grass HP Sisyrinchium mucronatum Michx. needletip blue‐eyed‐grass HP S2

127 (Table continues on next page.) 128 (Key to symbols and typefaces—p. 111. Index to all names—p. 132.)

HIGHER TAXON 2010 grass‐ Family PABS growth C3 / C4 land extirpa‐ Genus, species (& variety or subspecies) common name(s) status form (grasses) specialist ted (?) Liliaceae Erythronium americanum Ker Gawl. yellow trout‐lily, dogtooth‐violet HP Melanthiaceae Aletris farinosa L. colic‐root, white colic‐root PE HP X Orchidaceae Galearis spectabilis (L.) Raf. showy orchis HP Isotria verticillata (Muhl. ex Willd.) Raf. whorled‐pogonia HP Platanthera lacera (Michx.) G.Don ragged fringed‐orchid, green fringed HP O orchid Ruscaceae Maianthemum racemosum (L.) Link.. false Solomon’s‐seal, Solomon’s‐plume HP Polygonatum biflorum (Walter) Elliott smooth Solomon’s‐seal HP Polygonatum pubescens (Willd.) Pursh hairy Solomon’s‐seal HP Smilacaceae Smilax glauca Walter catbrier, cat greenbrier VW S2 Smilax herbacea L. carrion‐flower, smooth carrion‐flower VP Smilax rotundifolia L. common greenbrier, round‐leaf VW S2 greenbrier COMMELINID MONOCOTS Commelinaceae Commelina communis L. Asiatic dayflower HA Cyperaceae Carex albicans Spreng. white‐tinged sedge HP Carex amphibola Steud. eastern narrow‐leaf sedge HP Carex bicknellii Britton Bicknell’s sedge PE HP S1 Carex blanda Dewey eastern woodland sedge HP

HIGHER TAXON 2010 grass‐ Family PABS growth C3 / C4 land extirpa‐ Genus, species (& variety or subspecies) common name(s) status form (grasses) specialist ted (?) Carex digitalis Willd. slender woodland sedge HP Carex glaucodea Tuck. blue sedge HP S2 Carex hirsutella Mack. fuzzy‐wuzzy sedge HP S3 Carex hystericina Willd. bottlebrush sedge HP S2 X Carex pensylvanica Lam. Pennsylvania sedge HP Carex richardsonii R.Br. Richardson’s sedge PE HP S1 Carex scoparia Schkuhr ex Willd. broom sedge HP O X Carex swanii (Fernald) Mack. Swan’s sedge HP O Carex umbellata Willd. parasol sedge HP O Cyperus strigosus L. straw‐colored flatsedge HP O X Eleocharis tenuis (Willd.) Schult. slender spike‐rush HP O Fimbristylis annua (All.) Roem. & Schult. annual fimbry PT HA S1 Schoenoplectus tabernaemontani (Gmel.) great bulrush, soft‐stem bulrush HP Palla Scirpus atrovirens Willd. black bulrush, green bulrush HP S2 X Scirpus georgianus R.M.Harper Georgia bulrush HP Scleria pauciflora Muhl ex Willd. few‐flowered nut‐rush PT HP S1 Scleria triglomerata Michx. whip‐grass, nut‐rush PE HP S2 X Trichophorum planifolium (Sprengel) club‐rush, bashful bulrush HP Palla Juncaceae Juncus acuminatus Michx. sharp‐fruited rush, tapertip rush HP O X Juncus dichotomus Elliott forked rush PE HP S2 X Juncus effusus L. soft rush, lamp rush HP Juncus secundus P.Beauv. ex Poir. lopsided rush HP S2 Juncus tenuis Willd. var. tenuis path rush, poverty rush HP S3 Luzula multiflora (Ehrh.) Lej. field woodrush, common woodrush HP

129 (Table continues on next page.) 130 (Key to symbols and typefaces—p. 111. Index to all names—p. 132.)

HIGHER TAXON 2010 grass‐ Family PABS growth C3 / C4 land extirpa‐ Genus, species (& variety or subspecies) common name(s) status form (grasses) specialist ted (?) Poaceae

Agrostis gigantea Roth redtop HP C3 Agrostis perennans (Walter) Tuck. autumn bent, upland bent HP C3 S3

Andropogon gerardii Vitman big bluestem, turkeyfoot HP C4 S3 Andropogon gyrans Ashe Elliott’s beardgrass, Elliott’s bluestem PR HP C4 O

Andropogon virginicus L. broomsedge HP C4

Anthoxanthum odoratum L. sweet vernalgrass HP C3 Aristida dichotoma Michx. churchmouse three‐awn, povertygrass HA C4 S3

Aristida longespica Poir. var. longespica slender three‐awn, slimspike three‐awn TU HA C4 S2 X

Aristida purpurascens Poir. arrow‐feather three‐awn PT HP C4 S2 Bouteloua curtipendula (Michx.) Torr. side‐oats grama, tall grama PT HP C4 S1

Bromus inermis Leyss. smooth brome HP C3

Dactylis glomerata L. orchardgrass HP C3 Danthonia spicata (L.) P.Beauv. ex Roem. povertygrass, poverty oatgrass HP C3 S3 & Schult.

Deschampsia cespitosa (L.) P.Beauv. tufted hairgrass PT HP C3 S1

Dichanthelium acuminatum (Sw.) Gould tapered rosette grass, tapered panic‐ HP C3 S2 and C.A.Clark grass

Dichanthelium clandestinum (L.) Gould deer‐tongue HP C3 S3

Dichanthelium depauperatum (Muhl.) poverty panic‐grass, starved panic‐grass HP C3 S3 Gould

Dichanthelium dichotomum (L.) Gould cypress panic‐grass HP C3 S3 Dichanthelium oligosanthes (Schult.) Heller’s rosette grass, Heller’s witch PT HP C3 S2 Gould grass

Dichanthelium sphaerocarpon (Elliott) round‐seeded panic‐grass HP C3 S2 Gould

Dichanthelium villosissimum (Nash) long‐haired panic‐grass, whitehair PE HP C3 S3 Freckmann rosette grass

HIGHER TAXON 2010 grass‐ Family PABS growth C3 / C4 land extirpa‐ Genus, species (& variety or subspecies) common name(s) status form (grasses) specialist ted (?)

Digitaria filiformis (L.) Koeler slender crabgrass SP HA C4 S3 X Eragrostis pectinacea (Michx.) Nees Carolina lovegrass, tufted lovegrass HA C4 X

Eragrostis spectabilis (Pursh) Steud. purple lovegrass, tumblegrass HP C4 S3

Leersia oryzoides (L.) Sw. rice cutgrass HP C3 O X Leersia virginica Willd. whitegrass HP C3

Microstegium vimineum (Trin.) A.Camus. stiltgrass, Japanese stiltgrass, Nepalese HA C4 browntop

Miscanthus sinensis var. sinensis Andersson Chinese silvergrass, eulalia, maiden grass HP C4 Muhlenbergia mexicana (L.) Trin. Mexican muhly, satingrass HP C4 S2

Muhlenbergia sylvatica (Torr.) Torr. ex woodland muhly, woodland dropseed HP C4 X A.Gray

Panicum anceps Michx. beaked panic‐grass HP C4 O Panicum philadelphicum Bernh. ex Trin. Philadelphia panic‐grass HA C4 S2

Phleum pratense L. timothy HP C3

Poa compressa L. Canada bluegrass HP C3

Poa pratensis L. Kentucky bluegrass HP C3

Schedonorus pratensis (Huds.) P.Beauv. meadow fescue HP C3 Schizachyrium scoparium (Michx.) Nash little bluestem HP C4 S3 var. scoparium

Setaria pumila (Poir.) Schult. yellow foxtail HA C4 Sorghastrum nutans (L.) Nash Indian‐grass HP C4 S3

Sphenopholis obtusata (Michx.) Scribn. prairie wedgegrass, prairie wedgescale HP C3 S2 var. obtusata

Sporobolus vaginiflorus (Torr. ex A.Gray) poverty dropseed, poverty‐grass HA C4 S3 A.W.Wood

Tridens flavus (L.) A.Hitchc. purpletop HP C4 S3

131 (Table continues on next page.) 132

INDEX TO THE VASCULAR PLANTS OF THE UNIONVILLE BARRENS

Acalypha rhomboidea ...... 117 American holly ...... 122 Aristolochiaceae ...... 113 Acer platanoides ...... 120 American hornbeam ...... 116 arrow‐feather three‐awn ...... 130 Acer pseudoplatanus ...... 120 American planetree ...... 114 arrow‐leaf violet ...... 120 Acer rubrum ...... 120 American sycamore ...... 114 arrow‐wood, southern ...... 122 Achillea millefolium ...... 123 Amphicarpaea bracteata ...... 117 Asclepias syriaca ...... 122 Adoxaceae ...... 122 Amur honeysuckle ...... 125 Asclepias verticillata ...... 122 Ageratina altissima ...... 123 Anacardiaceae ...... 116 Asclepias viridiflora ...... 122 Ageratina aromatica ...... 123 Andropogon gerardii ...... 130 ash, white ...... 126 Agrimonia parviflora ...... 119 Andropogon gyrans ...... 130 Asiatic dayflower ...... 128 Agrimonia pubescens ...... 119 Andropogon virginicus ...... 130 aspen, bigtooth ...... 120 agrimony, downy ...... 119 Angelica venenosa ...... 122 Asplenium platyneuron ...... 112 agrimony, soft ...... 119 angelica, deadly ...... 122 aster, blue wood ...... 124 agrimony, southern ...... 119 angelica, hairy ...... 122 aster, calico ...... 124 Agrostis gigantea ...... 130 anise‐root ...... 122 aster, Pringle’s ...... 124 Agrostis perennans ...... 130 annual fimbry ...... 129 aster, serpentine ...... 124 ailanthus ...... 120 Antennaria neglecta ...... 123 aster, smooth blue ...... 124 Ailanthus altissima ...... 120 Antennaria plantaginifolia ...... 123 aster, white heath ...... 124 Aletris farinosa ...... 128 Anthoxanthum odoratum ...... 130 aster, white wood ...... 123 Allegheny blackberry ...... 120 Apiaceae ...... 122 aster, white‐topped ...... 124 Alliaceae ...... 127 Apios americana ...... 117 Asteraceae ...... 123 Alliaria petiolata ...... 116 Apocynaceae ...... 122 Asterids ...... 121 Allium vineale ...... 127 Apocynum cannabinum ...... 122 Athyrium filix‐femina ...... 112 alum‐root, American ...... 115 Appalachian groundsel ...... 124 Aureolaria pedicularia ...... 126 Amaranthaceae ...... 113 Aquifoliaceae ...... 122 autumn bent ...... 130 Ambrosia artemisiifolia ...... 123 Arabis lyrata ...... 116 autumn‐olive ...... 117 Ambrosia trifida ...... 123 Araceae ...... 127 avens, white ...... 119 Amelanchier arborea ...... 119 Aralia nudicaulis ...... 123 azalea, pink ...... 121 American alum‐root ...... 115 Araliaceae ...... 123 azure bluet ...... 127 American beech ...... 118 Arctium minus ...... 123 baby’s‐breath, false ...... 126 American black elderberry ...... 122 Arenaria serpyllifolia ...... 114 Balsaminaceae ...... 121 American chestnut ...... 118 Arisaema triphyllum ...... 127 Baptisia tinctoria ...... 117 American elder ...... 122 Aristida dichotoma ...... 130 Barbarea vulgaris ...... 116 American filbert ...... 116 Aristida longespica ...... 130 barberry, Japanese ...... 113 American hazelnut ...... 116 Aristida purpurascens ...... 130 barrens chickweed ...... 114 American hog‐peanut ...... 117 Aristolochia serpentaria ...... 113 bashful bulrush ...... 129

basil, wild ...... 125 black oak ...... 118 Botrychium virginianum ...... 112 bayberry ...... 119 black raspberry ...... 120 bottlebrush sedge ...... 129 bayberry, northern ...... 119 black snakeroot, Canadian ...... 122 Bouteloua curtipendula ...... 130 beaked panic‐grass ...... 131 black walnut ...... 118 bracken fern, northern ...... 113 bean, wild ...... 117 black‐alder ...... 122 Brassicaceae ...... 116 beardgrass, Elliott’s ...... 130 black‐cap ...... 120 broad‐leaf plaintain ...... 126 beaver‐poison ...... 122 black‐eyed‐susan ...... 124 brome, smooth ...... 130 bedstraw ...... 126 black‐gum ...... 121 Bromus inermis ...... 130 bedstraw, hairy ...... 126 black‐haw ...... 122 broom sedge ...... 129 bedstraw, white ...... 126 black‐seed plantain ...... 126 broomsedge ...... 130 beech, American ...... 118 blackberry, Allegheny ...... 120 browntop, Nepalese ...... 131 beechdrops ...... 126 blackberry, common ...... 120 bugleweed ...... 125 beefsteak‐plant ...... 125 blackberry, Pennsylvania ...... 120 bulbous buttercup ...... 115 beggar’s‐lice ...... 125 blackjack oak ...... 118 bulrush, bashful ...... 129 bellwort ...... 127 blisterwort ...... 115 bulrush, black ...... 129 bellwort, perfoliate ...... 127 bloodroot ...... 114 bulrush, Georgia ...... 129 bent, autumn ...... 130 blue aster, smooth ...... 124 bulrush, great ...... 129 bent, upland ...... 130 blue chicory ...... 123 bulrush, green ...... 129 Berberidaceae ...... 113 blue sedge ...... 129 bulrush, soft‐stem ...... 129 Berberis thunbergii ...... 113 blue violet, common ...... 120 bur cucumber ...... 117 Betulaceae ...... 116 blue wood aster ...... 124 bur cucumber, one‐seeded ...... 117 Bicknell’s hoary rockrose ...... 116 blue‐curls ...... 126 burdock, lesser ...... 123 Bicknell’s sedge ...... 128 blue‐eyed‐grass, narrow‐leaf ...... 127 burdock, woodland ...... 123 big bluestem ...... 130 blue‐eyed‐grass, needletip ...... 127 burning‐bush ...... 116 bigtooth aspen ...... 120 blue‐sailors ...... 123 bush‐clover, round‐headed ...... 117 bindweed, low ...... 125 blueberry, lowbush ...... 121 bush‐clover. slender ...... 117 bird cherry ...... 119 bluecurls, forked ...... 126 Bush’s oak ...... 118 bird’s‐eye speedwell ...... 126 bluegrass, Canada ...... 131 buttercup, bulbous ...... 115 bitter dock ...... 114 bluegrass, Kentucky ...... 131 buttonwood ...... 114 bittercress, hairy ...... 116 bluestem, big ...... 130 calico aster ...... 124 bittercress, Pennsylvania ...... 116 bluestem, Elliott’s ...... 130 Callitriche terrestris ...... 126 bittersweet, Oriental ...... 116 bluestem, little ...... 131 Calystegia spithamaea ...... 125 black bulrush ...... 129 bluet, azure ...... 127 Campanulaceae ...... 125 black cherry ...... 119 bluets ...... 127 campion, starry ...... 114 black elderberry, American ...... 122 Boehmeria cylindrica ...... 120 Canada bluegrass ...... 131 black huckleberry ...... 121 boneset, common ...... 123 Canada goldenrod ...... 124 black locust ...... 117 Boraginaceae ...... 125 Canada lettuce ...... 123 black medic ...... 117 border privet ...... 126 Canada thistle ...... 123 black nightshade ...... 127 Botrychium dissectum ...... 112 Canadian black snakeroot ...... 122

133 (Table continues on next page.) 134

Canadian horseweed ...... 123 Chelone glabra ...... 126 Commelina communis ...... 128 Canadian sanicle ...... 122 Chenopodium album ...... 113 Commelinaceae ...... 128 cankerweed ...... 124 cherry, bird ...... 119 commelinid monocots ...... 128 Cannabaceae ...... 116 cherry, black ...... 119 common blackberry ...... 119 Caprifoliaceae ...... 125 cherry, sweet ...... 119 common blue violet ...... 120 Cardamine hirsuta ...... 116 cherry, wild black ...... 119 common boneset ...... 123 Cardamine pensylvanica ...... 116 chestnut oak ...... 118 common chickweed ...... 114 Carduus nutans ...... 123 chestnut oak, dwarf ...... 118 common dandelion ...... 125 Carex albicans ...... 128 chestnut, American ...... 118 common greenbrier ...... 128 Carex amphibola ...... 128 chickweed, barrens ...... 114 common groundsel ...... 124 Carex bicknellii ...... 128 chickweed, common ...... 114 common hackberry ...... 116 Carex blanda ...... 128 chickweed, giant ...... 114 common marsh‐pink ...... 125 Carex digitalis ...... 129 chickweed, nodding ...... 114 common milkweed ...... 122 Carex glaucodea ...... 129 chicory, blue ...... 123 common mullein ...... 127 Carex hirsutella ...... 129 Chimaphila maculata ...... 121 common pear ...... 119 Carex hystericina ...... 129 Chinese silvergrass ...... 131 131common pepperweed ...... 116 Carex pensylvanica ...... 129 Christmas fern ...... 113 common polypody ...... 113 Carex richardsonii ...... 129 churchmouse three‐awn ...... 130 common ragweed ...... 123 Carex scoparia ...... 129 Cichorium intybus ...... 123 common serviceberry ...... 119 Carex swanii ...... 129 Cicuta maculata ...... 122 common three‐seeded mercury ...... 117 Carex umbellata ...... 129 cinquefoil, dwarf ...... 119 common winterberry ...... 122 Carolina lovegrass ...... 131 Circaea canadensis ...... 115 common wintercress ...... 116 Carolina rose ...... 119 Cirsium arvense ...... 123 common woodrush ...... 129 Carpinus caroliniana ...... 116 Cirsium muticum ...... 123 common yarrow ...... 123 carrion‐flower ...... 128 Cirsium pumilum ...... 123 coneflower, cutleaf ...... 124 carrion‐flower, smooth ...... 128 Cistaceae ...... 116 coneflower, green‐headed ...... 124 carrot, wild ...... 122 Claytonia virginica ...... 115 Convolvulaceae ...... 125 Carya glabra ...... 118 cleavers ...... 126 Conyza canadensis ...... 123 Caryophyllaceae ...... 114 cleavers ...... 126 corn speedwell ...... 126 Castanea dentata ...... 118 Clematis virginiana ...... 115 Cornaceae ...... 121 cat greenbrier ...... 128 Clinopodium vulgare ...... 125 Cornus florida ...... 121 catbrier ...... 128 clover, field ...... 117 Corylus americana ...... 116 Ceanothus americanus ...... 119 clover, red ...... 117 cowbane, spotted ...... 122 Celastraceae ...... 116 club‐rush ...... 129 crabapple ...... 119 Celastrus orbiculatus ...... 116 clubmoss, deep‐root ...... 112 crabapple, sweet ...... 119 Celtis occidentalis ...... 116 clubmosses ...... 112 crabgrass, slender ...... 131 Cerastium nutans ...... 114 Colchicaceae ...... 127 crowfoot, hooked ...... 115 Cerastium velutinum ...... 114 colic‐root ...... 128 Cryptotaenia canadensis ...... 122 Chamaecrista nictitans ...... 117 colic‐root, white ...... 128 cucumber, one‐seeded bur ...... 117

Cucurbitaceae ...... 117 Dichanthelium dichotomum ...... 130 Epifagus virginiana ...... 126 cudweed, fragrant ...... 124 Dichanthelium oligosanthes ...... 130 Epigaea repens ...... 121 Cupressaceae ...... 113 Dichanthelium sphaerocarpon ...... 130 Eragrostis pectinacea ...... 131 cut‐leaf false‐foxglove ...... 126 Dichanthelium villosissimum ...... 130 Eragrostis spectabilis ...... 131 cut‐leaf grape‐fern ...... 112 Digitaria filiformis ...... 131 Ericaceae ...... 121 cutgrass, rice ...... 131 Diphasiastrum tristachyum ...... 112 Erigeron annuus ...... 123 cutleaf coneflower ...... 124 dock, bitter ...... 114 Erigeron philadelphicus ...... 123 Cyperaceae ...... 128 dogtooth‐violet ...... 128 Erythronium americanum ...... 128 Cyperus strigosus ...... 129 dogwood, flowering ...... 121 Euasterids ...... 122 cypress panic‐grass ...... 130 downy agrimony ...... 119 Eudicots ...... 113 Dactylis glomerata ...... 130 dropseed, poverty ...... 131 eulalia ...... 131 daisy fleabane ...... 123 dropseed, woodland ...... 131 Euonymus alatus ...... 116 daisy fleabane, eastern ...... 123 Dryopteris carthusiana ...... 112 euonymus, winged ...... 116 daisy, ox‐eye ...... 124 Dryopteris intermedia ...... 112 Eupatorium perfoliatum ...... 123 dandelion, common ...... 125 Dryopteris marginalis ...... 112 Euphorbiaceae ...... 117 Danthonia spicata ...... 130 Duchesnea indica ...... 119 Eurosids ...... 116 darning‐needles, devil’s ...... 115 dwarf chestnut oak ...... 118 Eurybia divaricata ...... 123 Daucus carota ...... 122 dwarf cinquefoil ...... 119 Euthamia graminifolia ...... 123 dayflower, Asiatic ...... 128 dwarf sumac ...... 116 evening‐primrose, little ...... 115 deadly angelica ...... 122 dwarf upland willow ...... 120 evening‐primrose, narrow‐leaf ...... 115 deep‐root clubmoss ...... 112 early goldenrod ...... 124 evergreen wood‐fern ...... 112 deep‐rooted running‐pine ...... 112 early saxifrage ...... 115 Fabaceae ...... 117 deer‐tongue ...... 130 eastern daisy fleabane ...... 123 Fagaceae ...... 118 deerberry ...... 121 eastern marsh fern ...... 113 Fagus grandifolia ...... 118 Dennstaedtia punctilobula ...... 112 eastern narrow‐leaf sedge ...... 128 false baby’s‐breath ...... 126 Deparia acrostichoides ...... 112 eastern poison‐ivy ...... 116 false nettle ...... 120 Deptford pink ...... 114 eastern red‐cedar ...... 113 false Solomon’s‐seal ...... 128 Deschampsia cespitosa ...... 130 eastern woodland sedge ...... 128 false‐foxglove, cut‐leaf ...... 126 Desmodium ciliare ...... 117 ebony spleenwort ...... 112 false‐foxglove, fernleaf yellow ...... 126 Desmodium marilandicum ...... 117 Elaeagnaceae ...... 117 fameflower, quill ...... 115 Desmodium obtusum ...... 117 Elaeagnus angustifolia ...... 117 fancy fern ...... 112 Desmodium paniculatum ...... 117 Elaeagnus umbellata ...... 117 Faxon oak ...... 118 devil’s darning‐needles ...... 115 elder, American ...... 122 fern, Christmas ...... 113 dewberry, northern ...... 120 elderberry, American black ...... 122 fern, eastern marsh ...... 113 dewberry, prickly ...... 120 Eleocharis tenuis ...... 129 fern, ebony ...... 112 Dianthus armeria ...... 114 Elliott’s beardgrass ...... 130 fern, fancy ...... 112 Dichanthelium acuminatum ...... 130 Elliott’s bluestem ...... 130 fern, hay‐scented ...... 112 Dichanthelium clandestinum ...... 130 enchanter’s‐nightshade ...... 115 fern, interrupted ...... 112 Dichanthelium depauperatum ...... 130 English plantain ...... 126 fern, New York ...... 113

135 (Table continues on next page.) 136 fern, northern bracken ...... 113 frost grape ...... 115 gray goldenrod ...... 124 fern, rattlesnake ...... 112 fuzzy‐wuzzy sedge ...... 129 great bulrush ...... 129 fern, royal ...... 112 Galearis spectabilis ...... 128 green bulrush ...... 129 fern, sensitive ...... 112 Galium aparine ...... 126 green fringed orchid ...... 128 fern, silvery glade ...... 112 Galium circaezans ...... 126 green milkweed ...... 122 fern, southern ...... 112 Galium mollugo ...... 126 green‐headed coneflower ...... 124 fernleaf yellow false‐foxglove ...... 126 Galium pilosum ...... 126 greenbrier, cat ...... 128 ferns ...... 112 Galium triflorum ...... 126 greenbrier, common ...... 128 fescue, meadow ...... 131 garden yellow rocket ...... 116 greenbrier, round‐leaf ...... 128 few‐flowered nut‐rush ...... 129 garlic mustard ...... 116 ground‐cherry, long‐leaf ...... 127 field clover ...... 117 garlic, field ...... 127 ground‐pine, flat‐branched ...... 112 field garlic ...... 127 Gaylussacia baccata ...... 121 groundnut ...... 117 field pepperweed ...... 116 Gentianaceae ...... 125 groundsel, Appalachian ...... 124 field pussytoes ...... 123 Georgia bulrush ...... 129 groundsel, common ...... 124 field woodrush ...... 129 Geraniaceae ...... 115 gymnosperms ...... 113 fieldcress ...... 116 Geranium maculatum ...... 115 hackberry, common ...... 116 filbert, American ...... 116 geranium, spotted ...... 115 Hackelia virginiana ...... 125 Fimbristylis annua ...... 129 geranium, wood ...... 115 hairgrass, tufted ...... 130 fimbry, annual ...... 129 Geum canadense ...... 119 hairy angelica ...... 122 flannel‐plant ...... 127 giant chickweed ...... 114 hairy bedstraw ...... 126 flat‐branched ground‐pine ...... 112 giant ragweed ...... 123 hairy bittercress ...... 116 flat‐top goldenrod ...... 123 giant sunflower ...... 123 hairy small‐leaf tick‐trefoil ...... 117 flatsedge, straw‐colored ...... 129 glade fern, silvery ...... 112 hairy Solomon’s‐seal ...... 128 flax, slender yellow ...... 118 goatsbreard, yellow ...... 125 Hamamelidaceae ...... 114 fleabane ...... 123 golden‐alexander ...... 122 Hamamelis virginiana ...... 114 fleabane, daisy ...... 123 goldenrod, Canada ...... 124 harvestlice ...... 119 fleabane, eastern daisy ...... 123 goldenrod, early ...... 124 hay‐scented fern ...... 112 fleabane, Philadelphia ...... 123 goldenrod, flat‐top ...... 123 hazelnut, American ...... 116 flowering dogwood ...... 121 goldenrod, grass‐leaf ...... 123 heal‐all ...... 125 forked bluecurls ...... 126 goldenrod, gray ...... 124 heath aster ...... 124 forked rush ...... 129 goldenrod, wrinkle‐leaf ...... 124 heath aster, white ...... 124 foxtail, yellow ...... 131 goosegrass ...... 126 Helianthemum bicknellii ...... 116 Fragaria virginiana ...... 119 grama, side‐oats ...... 130 Helianthus giganteus ...... 123 fragrant bedstraw ...... 126 grama, tall ...... 130 Heller’s rosette grass ...... 130 fragrant cudweed ...... 124 grape‐fern, cut‐leaf ...... 112 Heller’s witch grass ...... 130 Fraxinus americana ...... 126 grape, frost ...... 115 helmet‐flower ...... 126 fringed loosestrife ...... 121 grape, pigeon ...... 115 Heuchera americana ...... 115 fringed orchid, green ...... 128 grape, summer ...... 115 hickory, pignut ...... 118 fringed‐orchid, ragged ...... 128 grass‐leaf goldenrod ...... 123 Hieracium venosum ...... 123

hoary frostweed ...... 116 jewelweed, orange ...... 121 Liliaceae ...... 128 hog‐peanut, American ...... 117 Juglandaceae ...... 118 Linaceae ...... 118 holly, American ...... 122 Juglans nigra ...... 118 Lindera benzoin ...... 113 honewort ...... 122 jumpseed ...... 114 Linum virginianum ...... 118 honeysuckle, Amur ...... 125 Juncaceae ...... 129 lion’s‐foot ...... 124 honeysuckle, Japanese ...... 125 Juncus acuminatus ...... 129 Liriodendron tulipifera ...... 113 honeysuckle, Morrow’s ...... 125 Juncus dichotomus ...... 129 little bluestem ...... 131 hooked crowfoot ...... 115 Juncus effusus ...... 129 little evening‐primrose ...... 115 hop‐clover, low ...... 117 Juncus secundus ...... 129 Lobelia inflata ...... 125 hornbeam, American ...... 116 Juncus tenuis ...... 129 Lobelia spicata ...... 125 horse‐nettle ...... 127 juneberry ...... 119 lobelia, spiked ...... 125 horseflyweed ...... 117 Juniperus virginiana ...... 113 locust, black ...... 117 horseweed, Canadian ...... 123 Kalmia latifolia ...... 121 long‐haired panic‐grass ...... 130 Houstonia caerulea ...... 127 Kentucky bluegrass ...... 131 long‐leaf ground‐cherry ...... 127 huckleberry, black ...... 121 king‐of‐the‐meadow ...... 115 long‐style sweet‐root ...... 122 Hyacinthaceae ...... 127 knotweed, pleat‐leaf ...... 114 Lonicera japonica ...... 125 Hypericaceae ...... 118 knotweed, slender ...... 114 Lonicera maackii ...... 125 Hypericum punctatum ...... 118 Lactuca canadensis ...... 123 Lonicera morrowii ...... 125 hyssop skullcup ...... 126 Lactuca serriola ...... 124 loosestrife, fringed ...... 121 Ilex opaca ...... 122 lady’s‐thumb, Oriental ...... 114 loosestrife, whorled ...... 121 Ilex verticillata ...... 122 lamb’s‐quarters ...... 113 loosestrife, whorled yellow ...... 121 Impatiens capensis ...... 121 Lamiaceae ...... 125 lopsided rush ...... 129 Indian strawberry ...... 119 lamp rush ...... 129 lovegrass, Carolina ...... 131 Indian‐grass ...... 131 lance self‐heal ...... 125 lovegrass, purple ...... 131 Indian‐hemp ...... 122 Lauraceae ...... 113 lovegrass, tufted ...... 131 Indian‐pipe ...... 121 Leersia oryzoides ...... 131 low bindweed ...... 125 Indian‐tobacco ...... 125 Leersia virginica ...... 131 low hop‐clover ...... 117 indigo, wild ...... 117 Lepidium campestre ...... 116 low smartweed ...... 114 intermediate wood‐fern ...... 112 Lepidium densiflorum ...... 116 lowbush blueberry ...... 121 interrupted fern ...... 112 Lespedeza capitata ...... 117 Luzula multiflora ...... 129 Iridaceae ...... 127 Lespedeza virginica ...... 117 Lycopodiaceae ...... 112 ironweed, New York ...... 125 lespedeza, roundhead ...... 117 Lycopodium obscurum ...... 112 ironwood ...... 116 lesser burdock ...... 123 lycopods ...... 112 Isotria verticillata ...... 128 lettuce, Canada ...... 123 Lycopus virginicus ...... 125 jack‐in‐the‐pulpit ...... 127 lettuce, prickly ...... 124 lyre‐leaf rockcress ...... 116 Japanese barberry ...... 113 lettuce, wild ...... 123 Lysimachia ciliata ...... 121 Japanese honeysuckle ...... 125 Leucanthemum vulgare ...... 124 Lysimachia quadrifolia ...... 121 Japanese stiltgrass ...... 131 licorice bedstraw ...... 126 madder, wild ...... 126 jewelweed ...... 121 Ligustrum obtusifolium ...... 126 Magnoliaceae ...... 113

137 (Table continues on next page.) 138

Magnoliids ...... 113 moss phlox ...... 121 non‐commelinid monocots ...... 127 Maianthemum racemosum ...... 128 moss‐pink ...... 121 northern bayberry ...... 119 maiden grass ...... 131 moth mullein ...... 127 northern bracken fern ...... 113 Malus coronaria ...... 119 mountain‐laurel ...... 121 northern dewberry ...... 120 Malus sp...... 119 mountain‐mint, narrow‐leaf ...... 125 northern red oak ...... 118 mandrake ...... 113 mountain‐mint, Virginia ...... 125 Norway maple ...... 120 maple‐leaf viburnum ...... 122 mouse‐ear, water ...... 114 nut‐rush ...... 129 maple, Norway ...... 120 Muhlenbergia mexicana ...... 131 nut‐rush, few‐flowered ...... 129 maple, sycamore ...... 120 Muhlenbergia sylvatica ...... 131 Nyssa sylvatica ...... 121 marginal wood‐fern ...... 112 muhly, Mexican ...... 131 Nyssaceae ...... 121 marsh fern ...... 113 muhly, woodland ...... 131 oak, black ...... 118 marsh fern, eastern ...... 113 mulberry, white ...... 119 oak, blackjack ...... 118 marsh‐pink, common ...... 125 mullein, common ...... 127 oak, Bush’s ...... 118 Maryland tick‐clover ...... 117 mullein, moth ...... 127 oak, chestnut ...... 118 mayapple ...... 113 multiflora rose ...... 119 oak, dwarf chestnut ...... 118 meadow fescue ...... 131 musk thistle ...... 123 oak, Faxon ...... 118 meadow zizia ...... 122 musquash‐root ...... 122 oak, northern red ...... 118 meadow‐rue, tall ...... 115 mustard, garlic ...... 116 oak, pin ...... 118 meadowsweet, white ...... 120 Myosoton aquaticum ...... 114 oak, post ...... 118 medic, black ...... 117 Myrica pensylvanica ...... 119 oak, scarlet ...... 118 Medicago lupulina ...... 117 Myricaceae ...... 119 oak, water ...... 118 Melanthiaceae ...... 128 Myrsinaceae ...... 121 oak, white ...... 118 Melilotus alba ...... 117 nannyberry ...... 122 oatgrass, poverty ...... 130 mercury, common three‐seeded ...... 117 narrow‐leaf blue‐eyed‐grass ...... 127 obtuse‐leaf privet ...... 126 Mexican muhly ...... 131 narrow‐leaf evening‐primrose ...... 115 Oenothera fruticosa ...... 115 Michaux’s stitchwort ...... 114 narrow‐leaf mountain‐mint ...... 125 Oenothera perennis ...... 115 Microstegium vimineum ...... 131 narrow‐leaf plantain ...... 126 old‐man‐in‐the‐spring ...... 124 milfoil ...... 123 narrow‐leaf sedge, eastern ...... 128 Oleaceae ...... 126 milkweed, common ...... 122 needletip blue‐eyed‐grass ...... 127 olive .... (see autumn‐olive, Russian‐olive) milkweed, green ...... 122 Nepalese browntop ...... 131 Onagraceae ...... 115 milkweed, whorled ...... 122 nettle, false ...... 120 one‐seeded bur cucumber ...... 117 milkwort, whorled ...... 119 nettle, smallspike false ...... 120 Onoclea sensibilis ...... 112 Minuartia michauxii ...... 114 nettle, stingless ...... 120 Ophioglossaceae ...... 112 Miscanthus sinensis ...... 131 131New Jersey tea ...... 119 orange jewelweed ...... 121 Mitchella repens ...... 127 New York fern ...... 113 orchardgrass ...... 130 Monotropa uniflora ...... 121 New York ironweed ...... 125 orchid, green fringed ...... 128 Moraceae ...... 119 nightshade, black ...... 127 Orchidaceae ...... 128 Morrow’s honeysuckle ...... 125 nodding chickweed ...... 114 orchis, showy ...... 128 Morus alba ...... 119 nodding thistle ...... 123 Oriental bittersweet ...... 116

Oriental lady’s‐thumb ...... 114 perilla ...... 125 Poa pratensis ...... 131 Ornithogalum umbellatum ...... 127 Perilla frutescens ...... 125 Poaceae ...... 130 Orobanchaceae ...... 126 Persicaria longiseta ...... 114 Podophyllum peltatum ...... 113 Osmorhiza longistylis ...... 122 Persicaria virginiana ...... 114 poison‐ivy ...... 116 Osmunda claytoniana ...... 112 Phemeranthus teretifolius ...... 115 poison‐ivy, eastern ...... 116 Osmunda regalis ...... 112 Philadelphia fleabane ...... 123 pokeweed ...... 114 Osmundaceae ...... 112 Philadelphia panic‐grass ...... 131 Polemoniaceae ...... 121 overlooked pussytoes ...... 123 Phleum pratense ...... 131 Polygala verticillata ...... 119 ox‐eye daisy ...... 124 Phlox subulata ...... 121 Polygalaceae ...... 119 Oxalidaceae ...... 119 phlox, moss ...... 121 Polygonaceae ...... 114 Oxalis dillenii ...... 119 Physalis subglabrata ...... 127 Polygonatum biflorum ...... 128 Packera anonyma ...... 124 Phytolacca americana ...... 114 Polygonatum pubescens ...... 128 panic‐grass, beaked ...... 131 Phytolaccaceae ...... 114 Polygonum aviculare ...... 114 panic‐grass, cypress ...... 130 pigeon grape ...... 115 Polygonum tenue ...... 114 panic‐grass, long‐haired ...... 130 pignut hickory ...... 118 Polypodiaceae ...... 112 panic‐grass, Philadelphia ...... 131 pin oak ...... 118 Polypodium virginianum ...... 113 panic‐grass, poverty ...... 130 Pinaceae ...... 113 polypody, common ...... 113 panic‐grass, round‐seeded ...... 130 pine, shortleaf ...... 113 polypody, rock ...... 113 panic‐grass, starved ...... 130 pine, yellow ...... 113 Polystichum acrostichoides ...... 113 panic‐grass, tapered ...... 130 pink azalea ...... 121 poplar ...... (see bigtooth aspen, tuliptree) panicled‐leaf tick‐trefoil ...... 117 pink, Deptford ...... 114 Populus grandidentata ...... 120 Panicum anceps ...... 131 Pinus echinata ...... 113 Portulacaceae ...... 115 Panicum philadelphicum ...... 131 pinxter‐flower ...... 121 post oak ...... 118 Papaveraceae ...... 114 pipsissewa ...... 121 Potentilla canadensis ...... 119 parasol sedge ...... 129 plaintain, broad‐leaf ...... 126 poverty dropseed ...... 131 Parthenocissus quinquefolia ...... 115 planetree, American ...... 114 poverty oatgrass ...... 130 partridge pea, sensitive ...... 117 Plantaginaceae ...... 126 poverty panic‐grass ...... 130 partridge‐berry ...... 127 Plantago lanceolata ...... 126 poverty rush ...... 129 pasture rose ...... 119 Plantago rugelii ...... 126 poverty‐grass ...... 131 pasture thistle ...... 123 plantain‐leaf pussytoes ...... 123 povertygrass ...... 130 path rush ...... 129 plantain, black‐seed ...... 126 povertygrass ...... 130 pear, common ...... 119 plantain, English ...... 126 prairie wedgegrass ...... 131 Pennsylvania bittercress ...... 116 plantain, narrow‐leaf ...... 126 prairie wedgescale ...... 131 Pennsylvania blackberry ...... 120 plantain, Rugel’s ...... 126 prairie willow ...... 120 Pennsylvania sedge ...... 129 Platanaceae ...... 114 Prenanthes altissima ...... 124 pepper‐grass, wild ...... 116 Platanthera lacera ...... 128 Prenanthes serpentaria ...... 124 pepperweed, common ...... 116 Platanus occidentalis ...... 114 prickly dewberry ...... 120 pepperweed, field ...... 116 pleat‐leaf knotweed ...... 114 prickly lettuce ...... 124 perfoliate bellwort ...... 127 Poa compressa ...... 131 prince’s‐pine, striped ...... 121

139 (Table continues on next page.) 140 privet, border ...... 126 Ranunculaceae ...... 115 round‐leaf fameflower ...... 115 privet, obtuse‐leaf ...... 126 Ranunculus bulbosus ...... 115 round‐leaf greenbrier ...... 128 prostrate knotweed ...... 114 Ranunculus recurvatus ...... 115 round‐seeded panic‐grass ...... 130 prostrate knotweed ...... 114 raspberry, black ...... 120 roundhead lespedeza ...... 117 Prunella vulgaris ...... 125 raspberry, wine ...... 120 royal fern ...... 112 Prunus avium ...... 119 rattlesnake fern ...... 112 Rubiaceae ...... 126 Prunus serotina ...... 119 rattlesnake‐root, tall ...... 124 Rubus allegheniensis ...... 119 Pseudognaphalium obtusifolium ...... 124 rattlesnake‐weed ...... 123 Rubus flagellaris ...... 120 Pteridium aquilinum ...... 113 red clover ...... 117 Rubus occidentalis ...... 120 puccoon, red ...... 114 red maple ...... 120 Rubus pensilvanicus ...... 120 purple lovegrass ...... 131 red maple ...... 120 Rubus phoenicolasius ...... 120 purpletop ...... 131 red oak, northern ...... 118 Rudbeckia hirta ...... 124 pussytoes, field ...... 123 red puccoon ...... 114 Rudbeckia laciniata ...... 124 pussytoes, overlooked ...... 123 red‐cedar, eastern ...... 113 Rugel’s plantain ...... 126 pussytoes, plantain‐leaf ...... 123 redtop ...... 130 Rumex acetosella ...... 114 Pycnanthemum tenuifolium ...... 125 Rhamnaceae ...... 119 Rumex obtusifolius ...... 114 Pycnanthemum virginianum ...... 125 Rhododendron periclymenoides ...... 121 running‐pine, deep‐rooted ...... 112 Pyrus communis ...... 119 Rhus copallina ...... 116 Ruscaceae ...... 128 Quaker‐ladies ...... 127 ribgrass ...... 126 rush, forked ...... 129 Queen Anne’s‐lace ...... 122 rice cutgrass ...... 131 rush, lamp ...... 129 Quercus ×bushii ...... 118 Richardson’s sedge ...... 129 rush, lopsided ...... 129 Quercus alba ...... 118 Robinia pseudoacacia ...... 117 rush, path ...... 129 Quercus coccinea ...... 118 rock polypody ...... 113 rush, poverty ...... 129 Quercus marilandica ...... 118 rock sandwort ...... 114 rush, sharp‐fruited ...... 129 Quercus marilandica × velutina ...... 118 rockcap ...... 113 rush, soft ...... 129 Quercus montana ...... 118 rockcress, lyre‐leaf ...... 116 rush, tapertip ...... 129 Quercus nigra ...... 118 rocket, garden yellow ...... 116 Russian‐olive ...... 117 Quercus palustris ...... 118 Rosa carolina ...... 119 Sabatia angularis ...... 125 Quercus prinoides ...... 118 Rosa multiflora ...... 119 sage willow ...... 120 Quercus prinoides × alba ...... 118 Rosaceae ...... 119 Salicaceae ...... 120 Quercus rubra ...... 118 rose‐pink ...... 125 Salix humilis ...... 120 Quercus stellata ...... 118 rose, Carolina ...... 119 salsify, yellow ...... 125 Quercus velutina ...... 118 rose, multiflora ...... 119 Sambucus canadensis ...... 122 quill fameflower ...... 115 rose, pasture ...... 119 sandwort, rock ...... 114 rabbit‐tobacco ...... 124 rosette grass, Heller’s ...... 130 sandwort, thyme‐leaf ...... 114 ragged fringed‐orchid ...... 128 rosette grass, tapered ...... 130 Sanguinaria canadensis ...... 114 ragweed, common ...... 123 rosette grass, whitehair ...... 130 sanicle, Canadian ...... 122 ragweed, giant ...... 123 Rosids ...... 115 Sanicula canadensis ...... 122 ragwort, Small’s ...... 124 round‐headed bush‐clover ...... 117 Sapindaceae ...... 120

sarsaparilla, wild ...... 123 Setaria pumila ...... 131 smooth brome ...... 130 sassafras ...... 113 shadbush ...... 119 smooth carrion‐flower ...... 128 Sassafras albidum ...... 113 sharp‐fruited rush ...... 129 smooth small‐leaf tick‐trefoil ...... 117 satingrass ...... 131 sheep sorrel ...... 114 smooth Solomon’s‐seal ...... 128 Saxifraga virginiensis ...... 115 sheepberry ...... 122 smooth white violet ...... 120 Saxifragaceae ...... 115 shining sumac ...... 116 snakeroot, Canadian black ...... 122 saxifrage, early ...... 115 shortleaf pine ...... 113 snakeroot, Virginia ...... 113 scallions ...... 127 showy orchis ...... 128 soft agrimony ...... 119 scarlet oak ...... 118 Sicyos angulatus ...... 117 soft rush ...... 129 Schedonorus pratensis ...... 131 side‐oats grama ...... 130 soft‐stem bulrush ...... 129 Schizachyrium scoparium ...... 131 Silene stellata ...... 114 Solanaceae ...... 127 Schoenoplectus silvergrass, Chinese ...... 131 131Solanum carolinense ...... 127 tabernaemontani ...... 129 silvery glade fern ...... 112 Solanum nigrum ...... 127 Scirpus atrovirens ...... 129 Simaroubaceae ...... 120 Solidago canadensis ...... 124 Scirpus georgianus ...... 129 Sisyrinchium angustifolium ...... 127 Solidago juncea ...... 124 Scleria pauciflora ...... 129 Sisyrinchium mucronatum ...... 127 Solidago nemoralis ...... 124 Scleria triglomerata ...... 129 skullcup, hyssop ...... 126 Solidago rugosa ...... 124 Scrophulariaceae ...... 127 skunk‐cabbage ...... 127 Solomon’s‐plume ...... 128 Scutellaria integrifolia ...... 126 sleepy‐dick ...... 127 Solomon’s‐seal, false ...... 128 sedge, Bicknell’s ...... 128 slender bush‐clover ...... 117 Solomon’s‐seal, hairy ...... 128 sedge, blue ...... 129 slender crabgrass ...... 131 Solomon’s‐seal, smooth ...... 128 sedge, bottlebrush ...... 129 slender knotweed ...... 114 Sonchus asper ...... 124 sedge, broom ...... 129 slender spike‐rush ...... 129 Sorghastrum nutans ...... 131 sedge, eastern woodland ...... 128 slender three‐awn ...... 130 sorrel, sheep ...... 114 sedge, fuzzy‐wuzzy ...... 129 slender woodland sedge ...... 129 sour‐gum ...... 121 sedge, parasol ...... 129 slender yellow flax ...... 118 sourgrass ...... 114 sedge, Pennsylvania ...... 129 slender yellow wood‐sorrel ...... 119 southern agrimony ...... 119 sedge, Richardson’s ...... 129 slimspike three‐awn ...... 130 southern arrow‐wood ...... 122 sedge, slender woodland ...... 129 small‐leaf tick‐trefoil, hairy ...... 117 southern lady‐fern ...... 112 sedge, Swan’s ...... 129 small‐leaf tick‐trefoil, smooth ...... 117 southern yellow wood‐sorrel ...... 119 sedge, white‐tinged ...... 128 small‐leaf white‐snakeroot ...... 123 sow‐thistle, spiny‐leaf ...... 124 self‐heal ...... 125 Small’s ragwort ...... 124 speedwell, bird’s‐eye ...... 126 Senecio vulgaris ...... 124 smallspike false nettle ...... 120 speedwell, corn ...... 126 sensitive fern ...... 112 smartweed, low ...... 114 Sphenopholis obtusata ...... 131 sensitive partridge pea ...... 117 Smilacaceae ...... 128 spicebush ...... 113 sensitive‐plant, wild ...... 117 Smilax glauca ...... 128 spike‐rush, slender ...... 129 Sericocarpus asteroides ...... 124 Smilax herbacea ...... 128 spiked lobelia ...... 125 serpentine aster ...... 124 Smilax rotundifolia ...... 128 spinulose wood‐fern ...... 112 serviceberry, common ...... 119 smooth blue aster ...... 124 spiny‐leaf sow‐thistle ...... 124

141 (Table continues on next page.) 142

Spiraea latifolia ...... 120 sweet cherry ...... 119 thyme‐leaf sandwort ...... 114 Sporobolus vaginiflorus ...... 131 sweet crabapple ...... 119 tick‐clover ...... 117 spotted cowbane ...... 122 sweet vernalgrass ...... 130 tick‐clover, Maryland ...... 117 spotted geranium ...... 115 sweet white violet ...... 120 tick‐trefoil, hairy small‐leaf ...... 117 spotted St. John’s‐wort ...... 118 sweet‐clover, white ...... 117 tick‐trefoil, panicled‐leaf ...... 117 spotted touch‐me‐not ...... 121 sweet‐root, long‐style ...... 122 tick‐trefoil, smooth small‐leaf ...... 117 spotted water‐hemlock ...... 122 sweet‐scented bedstraw ...... 126 tick‐trefoil, stiff ...... 117 spotted wintergreen ...... 121 sycamore maple ...... 120 timothy ...... 131 spring‐beauty ...... 115 sycamore, American ...... 114 touch‐me‐not, spotted ...... 121 St. Anthony’s‐turnip ...... 115 Symphyotrichum cordifolium ...... 124 Toxicodendron radicans ...... 116 St. John’s‐wort, spotted ...... 118 Symphyotrichum depauperatum ...... 124 Tragopogon dubius ...... 125 star‐of‐Bethlehem ...... 127 Symphyotrichum ericoides ...... 124 trailing‐arbutus ...... 121 starry campion ...... 114 Symphyotrichum laeve ...... 124 tree‐of‐heaven ...... 120 starved panic‐grass ...... 130 Symphyotrichum lateriflorum ...... 124 Trichophorum planifolium ...... 129 Stellaria media ...... 114 Symphyotrichum pilosum ...... 124 Trichostema dichotomum ...... 126 stickseed ...... 125 Symplocarpus foetidus ...... 127 Tridens flavus ...... 131 stickywilly ...... 126 tall grama ...... 130 Trifolium campestre ...... 117 stiff tick‐trefoil ...... 117 tall meadow‐rue ...... 115 Trifolium pratense ...... 117 stiltgrass ...... 131 tall rattlesnake‐root ...... 124 trout‐lily, yellow ...... 128 stiltgrass, Japanese ...... 131 tapered panic‐grass ...... 130 tufted hairgrass ...... 130 stingless nettle ...... 120 tapered rosette grass ...... 130 tufted lovegrass ...... 131 stitchwort, Michaux’s ...... 114 tapertip rush ...... 129 tuliptree ...... 113 straw‐colored flatsedge ...... 129 Taraxacum officinale ...... 125 tumblegrass ...... 131 strawberry, Indian ...... 119 tea viburnum ...... 122 tupelo ...... 121 strawberry, Virginia ...... 119 tea, New Jersey ...... 119 turkeyfoot ...... 130 strawberry, wild ...... 119 terrestrial water‐starwort ...... 126 turtlehead, white ...... 126 striped prince’s‐pine ...... 121 Thalictrum pubescens ...... 115 upland bent ...... 130 sugarberry ...... 116 Thelypteris noveboracensis ...... 113 Urticaceae ...... 120 sumac, dwarf ...... 116 Thelypteris palustris ...... 113 Uvularia perfoliata ...... 127 sumac, shining ...... 116 thistle, Canada ...... 123 Vaccinium pallidum ...... 121 sumac, winged ...... 116 thistle, musk ...... 123 Vaccinium stamineum ...... 121 summer grape ...... 115 thistle, nodding ...... 123 Verbascum blattaria ...... 127 sundrops ...... 115 thistle, pasture ...... 123 Verbascum thapsus ...... 127 sundrops ...... 115 thistle, swamp ...... 123 Verbena urticifolia ...... 127 sunflower, giant ...... 123 three‐awn, arrow‐feather ...... 130 Verbenaceae ...... 127 sunflower, swamp ...... 123 three‐awn, churchmouse ...... 130 vernalgrass, sweet ...... 130 swamp sunflower ...... 123 three‐awn, slender ...... 130 Vernonia noveboracensis ...... 125 swamp thistle ...... 123 three‐awn, slimspike ...... 130 Veronica arvensis ...... 126 Swan’s sedge ...... 129 three‐seeded mercury, common ...... 117 Veronica persica ...... 126

vervain, white ...... 127 white heath aster ...... 124 winged sumac ...... 116 Viburnum acerifolium ...... 122 white meadowsweet ...... 120 winterberry, common ...... 122 Viburnum dentatum ...... 122 white mulberry ...... 119 wintercress, common ...... 116 Viburnum lentago ...... 122 white oak ...... 118 wintergreen, spotted ...... 121 Viburnum prunifolium ...... 122 white sweet‐clover ...... 117 witch grass, Heller’s ...... 130 Viburnum setigerum ...... 122 white turtlehead ...... 126 witch‐hazel ...... 114 viburnum, maple‐leaf ...... 122 white vervain ...... 127 woman’s‐tobacco ...... 123 viburnum, tea ...... 122 white wood aster ...... 123 wood aster, blue ...... 124 Viola macloskeyi ...... 120 white‐snakeroot ...... 123 wood aster, white ...... 123 Viola sagittata ...... 120 white‐snakeroot, small‐leaf ...... 123 wood geranium ...... 115 Viola sororia ...... 120 white‐tinged sedge ...... 128 wood‐fern, evergreen ...... 112 Violaceae ...... 120 white‐topped aster ...... 124 wood‐fern, intermediate ...... 112 violet, arrow‐leaf ...... 120 whitegrass ...... 131 wood‐fern, marginal ...... 112 violet, smooth white ...... 120 whitehair rosette grass ...... 130 wood‐fern, spinulose ...... 112 violet, sweet white ...... 120 whorled loosestrife ...... 121 wood‐sorrel, slender yellow ...... 119 virgin’s‐bower ...... 115 whorled milkweed ...... 122 wood‐sorrel, southern yellow ...... 119 Virginia mountain‐mint ...... 125 whorled milkwort ...... 119 woodbine ...... 115 Virginia snakeroot ...... 113 whorled yellow loosestrife ...... 121 woodland burdock ...... 123 Virginia strawberry ...... 119 whorled‐pogonia ...... 128 woodland dropseed ...... 131 Virginia water‐horehound ...... 125 widow’s‐frill ...... 114 woodland muhly ...... 131 Virginia‐creeper ...... 115 wild basil ...... 125 woodland sedge, eastern ...... 128 Vitaceae ...... 115 wild bean ...... 117 woodland sedge, slender ...... 129 Vitis aestivalis ...... 115 wild black cherry ...... 119 woodrush, common ...... 129 Vitis vulpina ...... 115 wild carrot ...... 122 woodrush, field ...... 129 walnut, black ...... 118 wild indigo ...... 117 wrinkle‐leaf goldenrod ...... 124 water mouse‐ear ...... 114 wild lettuce ...... 123 yarrow, common ...... 123 water oak ...... 118 wild licorice ...... 126 yellow false‐foxglove, fernleaf ...... 126 water‐hemlock, spotted ...... 122 wild madder ...... 126 yellow flax, slender ...... 118 water‐horehound ...... 125 wild pepper‐grass ...... 116 yellow foxtail ...... 131 water‐horehound, Virginia ...... 125 wild sarsaparilla ...... 123 yellow goatsbreard ...... 125 water‐starwort ...... 126 wild sensitive‐plant ...... 117 yellow pine ...... 113 water‐starwort, terrestrial ...... 126 wild strawberry ...... 119 yellow rocket, garden ...... 116 wedgegrass, prairie ...... 131 wild‐chervil ...... 122 yellow salsify ...... 125 wedgescale, prairie ...... 131 willow, dwarf upland ...... 120 yellow trout‐lily ...... 128 whip‐grass ...... 129 willow, prairie ...... 120 yellow wood‐sorrel, slender ...... 119 white ash ...... 126 willow, sage ...... 120 yellow wood‐sorrel, southern ...... 119 white avens ...... 119 wine raspberry ...... 120 yellow‐poplar ...... 113 white bedstraw ...... 126 wineberry ...... 120 Zizia aptera ...... 122 white colic‐root ...... 128 winged euonymus ...... 116 zizia, meadow ...... 122

143

144

Appendix C. Arthropods of Special Conservation Concern that May Inhabit Unionville Barrens

It is next to certain that arthropod found there in 1987. To date, it is the only species of special conservation concern are animal species of special conservation present at the Unionville Barrens. However, concern confirmed at the Unionville to date no one has done a systematic animal Barrens. Other arthropods of special survey at the site. There are nearly 50 conservation concern are highly likely to be animal species of special concern, mainly found through professional surveys insects, known so far at the State Line conducted by qualified entomologists. Barrens, a series of serpentine grasslands Table C‐1 (next page) is a preliminary and woods along the Mason‐Dixon Line in list of insects of special conservation Pennsylvania and Maryland just 16 miles concern considered as likely past, present southwest of the Unionville Barrens. Even or future residents of the Unionville there, so far relatively little effort has been Barrens. The list includes 10 butterflies, 32 put into wildlife surveys except to search moths, 1 beetle and 2 hemipterans or “true for butterflies and moths. Scientists expect bugs” that depend in some way on plants to find many more kinds of rare insects and presently found at the site. The list is not in other arthropods on serpentine barrens any way exhaustive of the endangered, eventually. Searches have been made of the threatened or rare insect species that might Unionville Barrens specifically targeting inhabit the Unionville Barrens. Its utility is three rare insect species, two plant bugs in identifying several plant species as that feed on moss phlox and one beetle targets of management to enhance or whose larvae feed on the native grasses sustain habitat value for serpentine little bluestem and big bluestem. The rare barrens‐dependent animal life and as plant bugs were not found at Unionville but additional indicators of desired conditions the prairie leaf beetle, which lives mainly in to be monitored. the prairies of the Midwest and West, was

145

146

Table C‐1. Arthropods of special conservation concern that may inhabit Unionville Barrens. Sources: Pennsylvania Natural Heritage Program (2010); Rawlins (2007); Orndorff and Patten (2007); personal communication with B. Leppo, D. Schweitzer, A. Wheeler. global state known larval host plant(s) living in or near Unionville species common name rank* rank* Barrens (see Table B‐1 index, p. 126, for common names) BUTTERFLIES & SKIPPERS (Lepidoptera, in part) Amblyscirtes vialis roadside skipper G5 S2 (4) Agrostis, Poa Anthocharis midea falcate orangetip G4G5 S3 (2) Brassicaceae, especially Arabis, Cardamine Atrytonopsis hianna dusted skipper G4G5 S2 (2) Schizachyrium scoparium, Andropogon gerardii Callophrys gryneus juniper hairstreak G5 S3 (4) Juniperus virginiana Erynnis martialis mottled duskywing G3 SH (1) Ceanothus americanus Erynnis persius persius persius duskywing G5 S1S2 Baptisia tinctoria T1T3 Hesperia leonardus Leonard’s skipper G4 S3 (2) Schizachyrium scoparium, Bouteloua, Agrostis Hesperia metea cobweb skipper G4G5 S2 (2) Schizachyrium scoparium, Andropogon Hesperia sassacus Indian skipper G5 S3S4 Poaceae Nastra lherminier swarthy skipper G5 S2S3 Schizachyrium scoparium MOTHS (Lepidoptera, in part) Anisota stigma spiny oakworm moth G5 S1S2 (4) Quercus Apodrepanulatrix liberaria a geometer moth G4 S1S3 (2) Ceanothus americanus Artace cribraria dot‐lined white moth G5 S1 (4) Quercus (Prunus? Rosa?) Caripeta aretaria southern pine looper moth G4 S1S2 (2) unknown Catocala sp. 1 nr. jair pine woods underwing G5 S1 (4) unknown Catocala umbrosa an underwing moth G5 S1 (4) unknown Celastrina ladon lucia northern spring azure G5 S3S4 Ceanothus americanus Cisthene packardii Packard’s lichen moth G5 S1S3 (4) lichens Cisthene plumbea lead‐colored lichen moth G5 S1 (4) lichens Citheronia regalis regal moth G4G5 SU Carya, Juglans, Rhus

* G and S rarity ranks and conservation tier from Pennsylvania’s Comprehensive Wildlife Management Strategy: Invertebrates (numerals in parentheses) are explained in Appendix A (pp. 109–110).

global state known larval host plant(s) living in or near Unionville species common name rank* rank* Barrens (see Table B‐1 index, p. 126, for common names) Crambidia pura pure lichen moth G4 SU (4) unknown Cyclophora nanaria a geometrid moth G5 S1S2 (4) unknown Elaphria cornutinis a noctuid moth G5 SU (4) unknown Erastria coloraria broad‐lined erastria moth G3G4 S1 (2) Ceanothus americanus Hemileuca maia barrens buckmoth G5 S1S2 (4) Quercus, especially Q. ilicifolia Holomelina laeta joyful holomelina moth G4 S1S2 (2) unknown Hypagyrtis esther esther moth G5 S2S3 (4) unknown Idaea eremiata a geometrid moth G4 S1 (2) Quercus Idaea violacearia a wave moth G4 S1 (2) unknown Lagoa crispata black‐waved flannel moth G5 S1 (4) Malus, Rubus, Myrica, Quercus, Populus, Prunus, Sassafras Macrochilo hypocritalis an owlet moth G4 SU (4) unknown (Carex?) Metaxaglaea semitaria footpath sallow moth G5 S2 (4) Vaccinium corymbosum (V. pallidum?) Papaipema marginidens a borer moth G4 SU (4) unknown Papaipema pterisii bracken borer G5 S3 Pteridium aquilinum Parahypenodes quadralis a noctuid moth G4 SU (4) dead leaves Renia sp. 1 nr. discoloralis a noctuid moth G4 S1? (2) unknown Richia acclivis a noctuid moth G4G5 S1S2 (2) unknown Sutyna privata teltowa a noctuid moth G5T4 S1 (2) (Smilax?) Tolype notialis tolype moth G4G5 S1 (2) conifers Xestia elimata southern variable dart moth G5 S2S3 (4) unknown Xylotype capax broad sallow moth G4 S3 (2) Vaccinium corymbosum (Prunus? Malus? Quercus rubra?) Zanclognatha martha pine barrens zanclognatha G4 S1S2 (2) unknown, probably plant detritus

* G and S rarity ranks and conservation tier from Pennsylvania’s Comprehensive Wildlife Management Strategy: Invertebrates (numerals in parentheses) are explained in Appendix A (pp. 109–110).

147 (Table continues on next page,) 148

global state known larval host plant(s) living in or near Unionville species common name rank* rank* Barrens (see Table B‐1 index, p. 126, for common names) BEETLES (Coleoptera) Diabrotica cristata prairie leaf beetle G4G5?† S1?† roots of Andropogon gerardii, Schizachyrium scoparium, other Poaceae TRUE BUGS (Hemiptera) Polymerus tinctipes a plant bug G3?† S1?† Phlox subulata Trialeurodes phlogis a whitefly G2G3?† S1?† Phlox subulata

* G and S rarity ranks and conservation tier from Pennsylvania’s Comprehensive Wildlife Management Strategy: Invertebrates (numerals in parentheses) are explained in Appendix A (pp. 109–110). † Not yet ranked by NatureServe or the Pennsylvania Natural Heritage Program; ranks shown here are tentative approximations by R. Latham.

Appendix D. Notes on Design of Adaptive Management Trials

The key operational differences thoroughness of replication, the degree of between adaptive management and experimental control, and the strength of scientifically rigorous research involve the standards of evidence.

D.1 Replication Replication is vital to interpreting the plot‐wide averages are the data used in results of both controlled experiments and analyses. Treating the data from individual adaptive management, but adaptive quadrats or transects as replicates instead management typically involves fewer of as subsamples, a common mistake, replicates. In the context of testing violates fundamental assumptions management methods in a nature preserve, underlying the logic of inductive reasoning replicates are multiple geographically and leads to false or misleading inferences. defined, environmentally similar areas in True replication entails spatial which a particular kind of management interspersion of treatments, that is, activity is applied (or areas left unmanaged replicate trial plots cannot be clumped to serve as controls; see Experimental geographically by type. If trial plots control, pp. 151–152). These areas are often subjected to one treatment (or control called trial plots (and control plots). plots) are clumped together on the It is worth going into detail on two landscape, then the plots within the clump points to clear up common misconceptions would have to be considered as about replication: (1) multiple monitoring subsamples, and the entire clump of trial areas within trial plots are not replicates; plots—not the individual plots within it— and (2) different treatments have to be as a single replicate. Without interspersion intermixed on the landscape for trial plots of of treatments the trivial effect of spatial a particular management method (or autocorrelation (the tendency of nearby control plots) to be true replicates. samples to be more similar than more The areas on the landscape where distant samples) is confounded with, and monitoring is done are typically much cannot reliably be distinguished from, smaller than trial plots. They usually potentially interesting effects such as those consist either of survey plots or quadrats resulting from management trials. This (squares, rectangles or circles in which pitfall can be avoided by making sure that something is counted, measured or trial plots treated with different estimated) or transects (lines along which management methods, including no something is counted, measured or management (control plots), are estimated). Quadrats and transects are not interspersed or alternate with each other replicates, unless there is only one quadrat across the entire area of interest. or transect per management trial plot Replication is mandatory for both (which usually would be inadequate to scientific experiments and adaptive reflect the responses of indicators across an management. Adhering to the rules of entire trial plot). The data from all of the replication is the quickest and most quadrats or transects within a management effective way to separate the effects of one trial plot are averaged together and the trial or more management methods from 149

localized influences that are beyond the management a level of replication as low as managers’ control or beyond the power of N = 3 or even N = 2 (N is the smallest the monitoring protocol to detect. Without number of areas in each category of at least minimal replication, the risk is high management trials, e.g., treatment A, that some local peculiarity of a trial plot or treatment B or control) may show clear control plot will cause an effect that will be enough trends for inferences to be drawn, misinterpreted as having been caused by which can be used to refine or modify the management activity, or in the case of a management methods for further testing. control plot, by its absence. In adaptive

D.2 Randomization For labor‐ and expertise‐intensive is to prevent the results from being skewed metrics such as percent cover estimates for by unintentional bias, which is likely to all vascular plant species, it is not feasible occur where data‐collecting locations are to collect data over more than a small chosen by any other means. fraction of the total area. But the smaller The steps required for stratified random the area measured, the less likely it is to be sampling when the sampling unit is an area typical of the whole or to include a range of of land are best given in reference to an conditions representative of the whole. In example. Here we outline how to set up an most such cases, the best way of insuring array of permanent quadrats for that the areas chosen for monitoring will monitoring indicators of desired conditions yield useful information is to use stratified and their responses to management in the random sampling. Unionville Barrens’ seven management In scientific research, stratified random units (M.U.s): sampling is collecting data on subjects or (1) Using GIS, a local coordinate plane is set locations picked using a randomization up covering the area of interest (an procedure from a number of individual M.U. or the entire study area). subpopulations or categories (as always, Random points are scattered across the following the rules of replication). coordinate plane by multiplying the “Stratified” refers to the different width (along the horizontal axis) and subpopulations or categories (“strata”) then the height (along the vertical axis) from which subjects or locations are by each number in sequence on a list of chosen. Stratifying insures that roughly random numbers between 0 and 1 equal numbers of subjects or locations are (from a published random number list picked as targets of data collection from or made using a pseudo‐random each subpopulation or category so that number‐generating algorithm). valid comparisons can be made. (2) Within each M.U., random points are In the case of monitoring associated added to the map until there are at least with adaptive management, stratified three in each of three land types plus an random sampling usually means assessing additional three per acre for any area indicators at data‐collecting locations, above 1 acre in each land type. This will chosen using a randomization procedure generate a number of random points far within two or more predetermined in excess of the target number of categories of land. Typically those monitoring quadrats. The land types of categories are different vegetation types or interest are: plots where different management methods • existing grassland—here abbreviated are applied. The purpose of randomization EG (yellow on Map 4)

150

• forest and woodland to be restored to • Any point in FM falling in an area grassland—RG (overlap between severely disturbed by past mining or green on Map 4 and yellow on Map earthmoving is rejected. 10) (4) The number of monitoring quadrats to • forest management area—FM be placed within each land type within (untinted on Map 10) each M.U. is decided in advance and The random points are labeled made roughly proportional to the numerically within each land type available acreage; for example: within each M.U. in the sequence in • M.U. 2—two in EG, two in RG and two which they were generated. Their GPS in FM coordinates are recorded for • M.U. 3—one in EG, two in RG and two investigators to use in navigating to in FM them in the field. Any point falling • M.U. 6—three in EG, three in RG and within 10 m (30½ feet) of the M.U. one in FM boundary is discarded. (5) Within each land type within each M.U., (3) As a further hedge against selection random points are evaluated in the field bias, acceptance/rejection criteria are in the numerical sequence in which they established in advance to be applied were generated. This is another when evaluating each random point in safeguard against selection bias; the the field for suitability as a potential tendency otherwise would be to data‐collecting location. Examples: evaluate those nearest the point of • Each monitoring quadrat in EG must access first. have at least 20% cover but no more (6) Random points that fulfill all than 80% cover of gravel forb acceptance/rejection criteria when community within the serpentine examined in the field are accepted until grassland matrix. the target number for each land type is • Any point in EG falling in an area reached. Quadrat markers and directly beneath a large tree is identification tags are installed. rejected.

D.3 Experimental control Experimental control is separating the measuring how much difference it makes effects of the treatment or treatments instead of relying on subjective under investigation from the effects of impressions. In many cases the use of everything else. It is achieved in three basic control plots is unnecessary or ways; often a mixture of two or all three is inappropriate, for example in the autumn‐ used in the same trial or experiment. olive removal trials described on pp. 74–76. (1) Compare indicator responses between (2) Physically regulate or geographically managed trial plots and unmanaged areas. exclude factors that vary across the The unmanaged areas are called control landscape and are not part of the hypothesis plots or simply controls. Comparing data being tested, if they are likely to affect gathered using identical monitoring ecosystem and indicator response. This is protocols in both kinds of plots is the way accomplished by manipulating the to rate the effectiveness of a management extraneous variables directly to make them method, or to determine whether it makes as consistent as possible among all trial a significant difference at all, by actually areas (for instance, by thinning trees to a 151

consistent density in all plots), or by exclosures (positive controls). For some choosing trial areas that are already similar management questions, this two‐tiered to each other, or both. Matching site control approach is among the most conditions as fully as possible among all powerful methods of producing useful trial plots (and control plots, if they are information in the shortest practical used) is a robust way to distinguish amount of time. treatment effects from other effects, but it Physically controlling variables that are is not feasible in every landscape. Where not part of the hypothesis being tested is landscape variability is high, extraneous often costly in funds, time and labor, and effects can be controlled for by setting up choosing sites for management trials that trial plots and control plots in adjacent are nearly alike in those extraneous pairs, with each pair within a relatively variables is not always a luxury that uniform area of the landscape even though managers have available. Adaptive differing from the other pairs. Meaningful management, in contrast with scientific comparisons are made within each research, does not necessarily make such treatment‐control pair. Site‐wide trends stringent demands. Some adaptive may or may not emerge, but comparison management projects have been carried out among plot pairs in different environments without any experimental control. Although may lead to new insights about how those highly suspect—there is a much greater environmental differences interact with the hazard of misinterpreting the results— treatment(s) undergoing trial to produce trends inferred from uncontrolled trials different effects on the indicators. may be used to refine or modify (3) Employ both positive and negative management methods, which can then be controls. An example is examining the tested further. However, adhering to effects of invasive plants on a forest control procedures as strictly as resources ecosystem while recognizing that they will allow can pay off in long‐term time and depend partly on the intensity of deer cost savings. The better the control, the browsing. In this case the best approach is higher the chances will be of accurately to compare indicator responses in trial learning how well management methods plots where invasive species are removed perform and the lower the risk will be of with those in unmanaged plots (negative mistakenly crediting (or blaming) a controls), and within both types of plots management method for effects that comparing inside and outside fenced deer actually result from other causes.

D.4 Standards of evidence The standard of evidence is the management methods or between acceptable level of what statisticians call management and no management is an the type 1 error probability. That is the effect of the management activity when it likelihood of inferring that a management actually is not works out to be 5% or less, activity caused a particular response when then the difference is regarded as it actually did not. Experimenters in ecology significant (sometimes, especially in and wildlife biology customarily use an medical research, a stricter standard of 1 in arbitrary cutoff of a 1 in 20 (5%) 100 or 1 in 1,000 is used). If the difference probability of such an error to decide is large and highly consistent, then it is whether the difference is significant. In likely to meet the 5% criterion even in an other words, if the chance of inferring that a adaptive management trial. If the difference measured difference between two is subtle or muddled by things that vary

152

from place to place and are beyond the monitoring cycle are used as the basis for experimenters’ control, then experimental evaluating the effectiveness of alternative replication and control procedures need to management methods in achieving and be more stringent to detect it. In adaptive sustaining desired conditions. The methods management a lower standard of evidence are subject to updating based on the results can be accepted because adaptive revealed by monitoring. Modifications or management is inherently a long‐term entirely new methods might be proposed process—management is open‐ended, based on what is learned by analyzing unlike most scientific research projects— monitoring data. and information gained in this way is tested Standards of evidence are an important further in years‐long cycles of assessing consideration in how well monitoring data and modifying management methods and perform as a basis for updating continuing to collect and analyze management methods. The higher the comparative monitoring data. standard that is met—by judicious design In adaptive management, monitoring of management trials (including replication, data may be analyzed statistically if they randomization and experimental control) meet the assumptions of statistical methods and choice of indicators—the more or, more often, they are evaluated confident managers can be that qualitatively, for example, by examining interpreting monitoring data will lead to graphs. In either case, results of each wise management decisions.

153

Appendix E. Online Information Sources for Major Invasive Species in the Unionville Barrens ailanthus (Ailanthus altissima) Hoshovsky, M. C. 1988. Element stewardship abstract for Ailanthus altissima, tree‐of‐heaven. The Nature Conservancy, Arlington, Virginia. 13 pp. (http://www.invasive.org/weedcd/pdfs/tncweeds/ailaalt.pdf) Swearingen, J. M. and P. D. Pannill. 2009. Fact sheet: Tree of heaven. Alien Plant Working Group, Plant Conservation Alliance, Bureau of Land Management, Washington, D.C. 5 pp. (http://www.nps.gov/plants/alien/fact/aial1.htm) Fryer, J. L. 2010. Ailanthus altissima. Fire Effects Information System [online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, Montana. (http://www.fs.fed.us/database/feis/plants/tree/ailalt/all.html) garlic mustard (Alliaria petiolata) Nuzzo, V. 2000. Element stewardship abstract for Alliaria petiolata (Alliaria officinalis), garlic mustard. The Nature Conservancy, Arlington, Virginia. 19 pp. (http://www.invasive.org/weedcd/pdfs/tncweeds/allipet.pdf) Rowe, P. and J. M. Swearingen. 2005. Fact sheet: garlic mustard. Alien Plant Working Group, Plant Conservation Alliance, Bureau of Land Management, Washington, D.C. 3 pp. (http://www.nps.gov/plants/alien/fact/alpe1.htm) Munger, G. T. 2001. Alliaria petiolata. Fire Effects Information System [online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, Montana. (http://www.fs.fed.us/database/feis/plants/forb/allpet/all.html)

Japanese barberry (Berberis thunbergii) Swearingen, J. M. 2005. Fact sheet: Japanese barberry. Alien Plant Working Group, Plant Conservation Alliance, Bureau of Land Management, Washington, D.C. 3 pp. (http://www.nps.gov/plants/alien/fact/beth1.htm) Zouhar, K. 2008. Berberis thunbergii. Fire Effects Information System [online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, Montana. (http://www.fs.fed.us/database/feis/plants/shrub/berthu/all.html)

Oriental bittersweet (Celastrus orbiculatus) Dreyer, G. D. 1994. Element stewardship abstract for Celastrus orbiculatus, Asiatic bittersweet. The Nature Conservancy, Arlington, Virginia. 12 pp. (http://www.invasive.org/weedcd/pdfs/tncweeds/celaorb.pdf) Swearingen, J. M. 2006. Fact sheet: Oriental bittersweet. Alien Plant Working Group, Plant Conservation Alliance, Bureau of Land Management, Washington, D.C. 4 pp. (http://www.nps.gov/plants/alien/fact/ceor1.htm) Fryer, J. L. 2011. Celastrus orbiculatus. Fire Effects Information System [online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, Montana. (http://www.fs.fed.us/database/feis/plants/vine/celorb/all.html)

154

Canada thistle (Cirsium arvense) Nuzzo, V. 1997. Element stewardship abstract for Cirsium arvense, Canada thistle, creeping thistle, Californian thistle. The Nature Conservancy, Arlington, Virginia. 32 pp. (http://www.invasive.org/weedcd/pdfs/tncweeds/cirsarv.pdf) Thunhorst, G. and J. M. Swearingen. 2005. Fact sheet: Canada thistle. Alien Plant Working Group, Plant Conservation Alliance, Bureau of Land Management, Washington, D.C. 3 pp. (http://www.nps.gov/plants/alien/fact/ciar1.htm) Zouhar, K. 2001. Cirsium arvense. Fire Effects Information System [online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, Montana. (http://www.fs.fed.us/database/feis/plants/forb/cirarv/all.html) autumn‐olive (Elaeagnus umbellata) Sather, N. and N. Eckardt. 1987. Element stewardship abstract for Elaeagnus umbellata. The Nature Conservancy, Arlington, Virginia. 4 pp. (http://www.invasive.org/weedcd/pdfs/tncweeds/elaeumb.pdf) Munger, G. T. 2003. Elaeagnus umbellata. Fire Effects Information System [online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, Montana. (http://www.fs.fed.us/database/feis/plants/shrub/elaumb/all.htm) winged euonymus (Euonymus alatus) Martin, T. 2000. Weed alert! Euonymus alatus (Thunb.) Siebold (burning bush, winged euonymus, winged wahoo, winged spindle‐tree, Japanese spindle‐tree). Center for Invasive Species and Ecosystem Health. (http://www.invasive.org/gist/alert/alrteuon.html) Fryer, J. L. 2009. Euonymus alatus. Fire Effects Information System [online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, Montana. (http://www.fs.fed.us/database/feis/plants/shrub/euoala/all.html)

Japanese honeysuckle (Lonicera japonica) Nuzzo, V. 1997. Element stewardship abstract for Lonicera japonica, Japanese honeysuckle. The Nature Conservancy, Arlington, Virginia. 22 pp. (http://www.invasive.org/weedcd/pdfs/tncweeds/lonijap.pdf) Bravo, M. A. 2005. Fact sheet: Japanese honeysuckle. Alien Plant Working Group, Plant Conservation Alliance, Bureau of Land Management, Washington, D.C. 3 pp. (http://www.nps.gov/plants/alien/fact/loja1.htm) Munger, G. T. 2002. Lonicera japonica. Fire Effects Information System [online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, Montana. (http://www.fs.fed.us/database/feis/plants/shrub/lonjap/all.html)

Amur honeysuckle (Lonicera maackii) and other nonnative bush honeysuckles Batcher, M. S. and S. A. Stiles. 2000. Element stewardship abstract for Lonicera maackii (Rupr.) Maxim (Amur honeysuckle), Lonicera morrowii A. Gray (Morrow’s honeysuckle), Lonicera tatarica L. (Tatarian honeysuckle), Lonicera × bella Zabel (Bell’s honeysuckle), the bush honeysuckles. The Nature Conservancy, Arlington, Virginia. 12 pp. (http://www.invasive.org/weedcd/pdfs/tncweeds/loni_sp.pdf)

155

Williams, C. E. 2005. Fact sheet: exotic bush honeysuckles. Alien Plant Working Group, Plant Conservation Alliance, Bureau of Land Management, Washington, D.C. 3 pp. (http://www.nps.gov/plants/alien/fact/loni1.htm) Munger, G. T. 2005. Lonicera spp. Fire Effects Information System [online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, Montana. (http://www.fs.fed.us/database/feis/plants/shrub/lonspp/all.html) stiltgrass (Microstegium vimineum) Tu, M. 2000. Element stewardship abstract for Microstegium vimineum, Japanese stilt grass, Nepalese browntop, Chinese packing grass. The Nature Conservancy, Arlington, Virginia. 8 pp. (http://www.invasive.org/weedcd/pdfs/tncweeds/micrvim.pdf) Swearingen, J. M. and A. Sheherezade. 2008. Fact sheet: Japanese stiltgrass. Alien Plant Working Group, Plant Conservation Alliance, Bureau of Land Management, Washington, D.C. 4 pp. (http://www.nps.gov/plants/alien/fact/mivi1.htm) Fryer, J. L. 2011. Microstegium vimineum. Fire Effects Information System [online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, Montana. (http://www.fs.fed.us/database/feis/plants/graminoid/micvim/all.html) mile‐a‐minute (Persicaria perfoliata; syn. Polygonum perfoliatum) Gerlach, J. A., J. Hough‐Goldstein and J. Swearingen. 2010. Fact sheet: mile‐a‐minute weed. Alien Plant Working Group, Plant Conservation Alliance, Bureau of Land Management, Washington, D.C. 4 pp. (http://www.nps.gov/plants/alien/fact/pepe1.htm) Stone, K. R. 2010. Polygonum perfoliatum. Fire Effects Information System [online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, Montana. (http://www.fs.fed.us/database/feis/plants/vine/polpef/all.html) lesser celandine (Ranunculus ficaria; syn. Ficaria verna) Swearingen, J. M. 2010. Fact sheet: Fig buttercup. Alien Plant Working Group, Plant Conservation Alliance, Bureau of Land Management, Washington, D.C. 3 pp. (http://www.nps.gov/plants/alien/fact/rafi1.htm) black locust (Robinia pseudoacacia) Converse, C. K. 1984. Element stewardship abstract for Robinia pseudoacacia, black locust. The Nature Conservancy, Arlington, Virginia. 14 pp. (http://www.invasive.org/weedcd/pdfs/tncweeds/robipse.pdf) Wieseler, S. 2005. Fact sheet: black locust. Alien Plant Working Group, Plant Conservation Alliance, Bureau of Land Management, Washington, D.C. 3 pp. (http://www.nps.gov/plants/alien/fact/rops1.htm) Stone, K. R. 2009. Robinia pseudoacacia. Fire Effects Information System [online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, Montana. (http://www.fs.fed.us/database/feis/plants/tree/robpse/all.html)

156

multiflora rose (Rosa multiflora) Eckardt, N. 1987. Element stewardship abstract for Rosa multiflora, rambler rose, multiflowered rose. The Nature Conservancy, Arlington, Virginia. 8 pp. (http://www.invasive.org/weedcd/pdfs/tncweeds/rosamul.pdf) Bergmann, C. and J. M. Swearingen. 2005. Fact sheet: multiflora rose. Alien Plant Working Group, Plant Conservation Alliance, Bureau of Land Management, Washington, D.C. 3 pp. (http://www.nps.gov/plants/alien/fact/romu1.htm) Munger, G. T. 2002. Rosa multiflora. Fire Effects Information System [online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, Montana. (http://www.fs.fed.us/database/feis/plants/shrub/rosmul/all.html) wineberry (Rubus phoenicolasius) Spencer, N. R. 2005. Fact sheet: wineberry. Alien Plant Working Group, Plant Conservation Alliance, Bureau of Land Management, Washington, D.C. 2 pp. (http://www.nps.gov/plants/alien/fact/ruph1.htm) Innes, R. 2009. Rubus phoenicolasius. Fire Effects Information System [online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, Montana. (http://www.fs.fed.us/database/feis/plants/shrub/rubpho/all.html)

157

R Xgw

T k n RT 340 e k u

West e e e R

2 r e tin Downingtown East Caln C r n

RT 322 8 1. Shaded relief layer received from PAMAP Program,e PA DCNR

2 y Unionville Barrens Study Area Boundary e C p Brandywine 2 all S e r 8 Borough Township V (www.pasda.psu.edu). y R T T Township le R T d R 2. Unionville Barrens Study Area Boundaryi determined by Roger R Natural Lands Trust Preserve T West R R re 3 T 0 T r C e Latham in "Protecting the Unionville h Barrens" (2005). Willistown 34 Beav e 2 3 k c 4 2 Whiteland 0 3. Bedrock Geology boundaries receivedn from PennsylvaniaTownship a Municipal BoundariesWest Caln 3 r 4 Township Geological Survey from 1980 State GeologyB Map. 0 t

Township Caln s lley Run S a 4. Waterways, municipal boundaries, majora roads, public and V h E E

RT 30 u Township a

Major Roads Ea g s s

t Branc protected lands received from Chester County.

h a t East Goshen B r

r B a Xu t Township R Valley n r R 2 d a Waterways Disclaimer: This map is not a survey.T The information impartedu with 8 y u n Xu n n T w ck R R Township un c o RT 30 d R h Xu oa R i Br this map is meant to assist Natural Lands Trust, Inc., describe the n 3 C dl R e 5 Ri e hes ekplacement of certain retained, reserved,2 or excluded rights andy to Conservation Organization Ownership T C te Cre C Xu r ree re calculate acreage figures. Property boundaries, while approximate, k 8 Xwc e 2 Xu Xu Conservation Organization Easement City of k were established using the best available information, which may Xu have included: surveys, tax maps, field mapping using G.P.S., Xu Coatesville West Goshen Xgw and/or orthophotos. Natural Lands Trust, Inc., makes no RT H County Agriculture Easement 30 Township un t Xu representation as to the accuracy of said property lines (or any e r s Run Xw Xu other lines), and no liability is assumed by reason of reliance RT 3Municipal0 Open Space and RecreationValley Xu thereon. Use of this map for other than its intended purpose Township un RT Xu RT 322 BP er R Xu requires the written consent of Natural Lands Trust, Inc. Sadsbury Suck Homeowner Association Land 2 22 RT 3 T 37 South 3 RT 3 Township R RT Xu Xu

Coatesville Xwc B 322 Bedrock Geology Boundary Xu RT 3 2 r 8 Borough o West Bradford a d Township RT 352 T R 16 RT 3 Bedrock Dike u 2 R n RT RT 322 Xu r Run West Chester lo Xs y Borough T a 2 RT 372 84 Den nis Ru n R Run Xw T ad n T ro Xu u 3

B o R R 0 h rs 2

Bedrock Formations East ck e RT 926 1 2 62 a 1 Stroud l Fallowfield T B T T R Xgw XsR Serpentinite Township Preserve East Bradford Township Westtown

Xw Schist (Wissahickon Formation) k

e Township

e Xgw

r Xpc Schist (Peters Creek Formation) un C Bu ck R Xpc e Xwc Schist (Octoraro Formation) Xu in dywin Xpc w e n y Xu

a C nd RT 926

0 We r r ra Xsq Quartzite (Setters Formation) e 1 st B B ranch B B u Xu e ck h Run k c mgh Mafic gneiss n T T a n r 2 R Xu u B 4 Xu fgh Felsic gneiss R Xs t 8 s l n a Xu a E T Xu R W R n T n ChesLen u 2 Thornbury Birch Ru Newlin R 0 2 RT 926 Township B m Township Preserve ra lu R nd P R yw Radley n T fgh ine C u T r R e 322 Highland Xu 8 e Xw Xu k 2 Xs Township R Xu a Xpg d l Xpg Xs e Xpg Pocopson y Xu Mgh R

Xw u

Xpg Township n Trd R Xw Xs RT 926 T Xu

1 0 52 842 Xu RT Xgw T Xs 841 R RT Xu Mgh pso co n Cree Birmingham RT 82 Xs Xs o k Xs Xw P Xs Township W est Branch Che Xgw s ter Cr eek n West u Xu ts R Marlborough 82 RT Xw et nn Xu Be Township Xu Xs D n RT 842 oe R u Xs Run rinto n Xu RT 926 B Xs Run t s fgh net RT 842 Ben fgh 2 East Xs 5

T T W Marlborough R Harv

e e n

s RT 1 y u t Xsq

RT 41 Township g Run R B Rin

fgh r

c fgh Londonderry h RT 1 RT 52 Pennsbury Township R e

d Township C

l a

RT 41 y

C r RT 1

R e R e l u M T il n raigs ill un k M C R Xu M s i 8 Kennett ig E d 4 Cra a dl e Br 1 anch Xu s R W Township R h t T i T t Bran e London R c 7 C l h 9 T 5 6 a Grove 2 B y C i r e g

e Township k E e

k Cre l Xu 8 r

k 2 e av C e

r New Garden B

e 6

e 9

Upper k Township 7 12 Miles Kennett Oxford T R Penn Square Township Township Borough

Xgw

Xu Map 1. Landscape context

UNIONVILLE BARRENS STUDY Miles 0 2 4 1031 Palmers Mill Road, Media, PA 19063 Newlin Township, Chester County, Pennsylvania 610-353-5587 ~ www.natlands.org Compiled By: MTM 12/19/11 3 3 5 6 0 00 0 3 3 10 70 3 3 10 3 0 0 1. Contours (2 ft Interval) received from PAMAP Program, PA Contours1 (2 ft Interval) 3 320 0 340 0 4 8 32 0 DCNR (www.pasda.psu.edu). 0 8 3 2. Waterways and Parcel Boundaries received from Chester 39 33 Waterways 0 340 0 330 County. 350 4 0 0 00 39 29 3. Bedrock Geology Boundary and Dikes received from 40 1937 Grassland Area within Serpentinite Outrcop 10 0 40 3 4 30 3 Pennsylvania Geological Survey from 1980 State Geology Map. 3 0 6 41 40 0 310 4. 1937 Historical Aerial Photography received from Pennsylvania 0 0 32 0 0 Bedrock Formation Boundary 1 0 5 Geological Survey and PHMC (www.pasds.psu.edu). 0 3 35 3 2 0 Xw 3 0 4 9 340 40 0 3 0 4 0 4 20 38 0 0 0 1 3 3 Disclaimer: This map is not a survey. The information imparted with 5 Bedrock Dike 6 4 0 0 0 0 3 7 5 3 3 3 3 0 5 0 0 3 this map is meant to assist Natural Lands Trust, Inc., describe the 3 0 420 41 4 3 4 3 9 3 3 8 0 3 7 0 2 placement of certain retained, reserved, or excluded rights and to 0 0 3 0 Bedrock Formations 3 1 5 3 2 calculate acreage figures. Property boundaries, while approximate, 0 0 0 0 0 3 10 20 were established using the best available information, which may 9 3 3 3 Serpentinite4 3 80 40 10 3 have included: surveys, tax maps, field mapping using G.P.S., Xs 350 4 Xs 3 and/or orthophotos. Natural Lands Trust, Inc., makes no 0 3 5 33 0 0 3 representation as to the accuracy of said property lines (or any Schist (Wissahickon4 Formation) 6 0 0 0 Xw 0 5 other lines), and no liability is assumed by reason of reliance 40 3 3 thereon. Use of this map for other than its intended purpose 4 50 4 1 0 400 0 3 3 5 requires the written consent of Natural Lands Trust, Inc. Pegmatite dike 0 3 Xpg 4 4 2 2 0 0 39 34 3 0 0 7 0 0 0 40 Diabase dike 4 3 3 3 0 0 7 Trd 3 0 0 4 4

9 4 8 1 3 0 3 0 3 0 3 0 41 31 0

3 8 0 0 6 F 3 0 4 430 3 3 6 4 3 3 10 4 0 e 0 4

5 0 3 0 3 3 0 5 3 8 50 0 400 41 l 3 0 0 42 2 d 4 0 2 420 0 3 4 50 0 4 3 3

3 3 0 s 7 10 6 4 3

8 0 5

4 3 p 0 1 0 34 0 0 3 1 3 39 3 4 8 0 0 0

0 3 0 a 4 9 7 0 0 3 39 0 0 380 6 1 80 3 n r 4 3 u 0

370 7 R R 3 0 2 0 4 1 0 340 4 0 m 4 0 8 4 0 3 0 3 u 0 340 0 4 5 u 3 2 3 4

0 n 0 6 0 d 3 3 5 4 3 0 0 1 8 4 n 0 3 0 35 3 9 50 0 4 3 3 0 4 0 0 u 5 0 8 r 3 3 o 3 3 3 6

6 0 0 7 0

0 8 9 C 0 0 3 0 0 0 0 3 0 36 37 0 1 4 350 4 4 3 6 4

0 1

0 410 380 40 4 4 0 370 2 0 0 3 0 0 7 380 0 2 3 0 8 4 3 4 5 3 0 390 0

Xpg 90 3 3 390 8 0 3 0 8 7 380 0 3 0 40

3 9 10 0 4 40 4 0 0 10 40 10 10 Xpg 4 4 380

3 0 9 1 0 0 4 8 3 0 0 2 4 2 4 1 0 4 4 10 4 0 4 0 0 10 1 0 4 0 3 9 0 3 3 4 0 420

1 3 0 9

0 0 1 4 4 3 410 0 2 4 0 414 1 440 4 0 3 3 0 2 n 3 450 Xw u 0 0 4 2 4 R 4 4 0 4 0 4 0 0 3 0 4 45 4 e 3 0 n 40 450 4 440 0 i 46 t 4 0 1 450 5 460 0 n 4 0 2 4 50 e 4 4 5 p 0 8 460 0 44 4 4 r 0 46 e 4 0 50 S 0 0 4 0 3 6 0 46 4 3 7 4 0 4 Xpg 0 00 0 0 4 46 450 370 0 4 47 7 6

4 3 4 80

0 3 1

4 2 40 0 0 Trd 4

Map 2. Serpentine grasslands, 1937 UNIONVILLE BARRENS STUDY Feet 1031 Palmers Mill Road, Media, PA 19063 Newlin Township, Chester County, Pennsylvania 0 150 300 610-353-5587 ~ www.natlands.org Compiled By: MTM 12/16/11 3 3 5 6 0 00 0 3 3 10 70 3 3 10 3 1. Contours (2 ft Interval) received from PAMAP Program, PA Contours0 (2 ft Interval) 0 1 3 320 0 340 0 4 8 32 0 DCNR (www.pasda.psu.edu). 0 8 3 2. Waterways and Parcel Boundaries received from Chester Waterways 39 33 0 County. 340 0 330 350 4 0 0 00 39 29 3. Bedrock Geology Boundary and Dikes received from 1971 Grassland Area within Serpentinite Outcrop 40 10 0 40 3 Pennsylvania Geological Survey from 1980 State Geology Map. 4 30 3 3 0 4. 1971 Historical Aerial Photography received from Pennsylvania 6 41 40 0 310 0 0 32 Bedrock Formation Boundary 0 0 Geological Survey and PHMC (www.pasds.psu.edu). 1 0 5 0 3 35 3 2 0 Xw 3 0 4 9 340 40 0 3 0 4 0 4 20 38 0 0 Bedrock Dike 0 Disclaimer: This map is not a survey. The information imparted with 1 3 3 5 6 4 0 0 0 0 3 7 5 3 3 3 3 0 this map is meant to assist Natural Lands Trust, 5Inc., describe the 0 0 3 3 0 420 41 4 3 4 3 9 3 3 8 0 3 7 placement of certain retained, reserved, or excluded rights and to Bedrock0 Formations 2 0 0 3 0 3 1 5 3 2 calculate acreage figures. Property boundaries, while approximate, 0 0 0 0 were established using the best available information, which may 0 3 10 20 Serpentinite 9 3 3 3 4 3 80 4 Xs 1 3 0 have included: surveys, tax maps, field mapping using G.P.S., 0 350 4 Xs and/or orthophotos. Natural Lands Trust, Inc., makes no 3 0 3 5 33 0 0 representation as to the accuracy of said property lines (or any Schist (Wissahickon Formation) 3 Xw 4 6 0 0 0 other lines), and no liability is assumed by reason of reliance 0 5 0 3 34 thereon. Use of this map for other than its intended purpose 4 50 4 1 0 400 0 3 Pegmatite dike 3 5 requires the written consent of Natural Lands Trust, Inc. Xpg 0 3 4 42 2 0 0 39 34 3 0 0 7 0 0 Diabase dike 0 40 4 3

Trd 3 3 0 0 7 3 0 0 4 4

9 4 8 1 3 0 3 0 3 0 3 0 41 31 0

3 8 0 0 6 F 3 0 4 430 3 3 6 4 3 3 10 4 0 e 0 4

5 0 3 0 3 3 0 5 3 8 50 0 400 41 l 3 0 0 42 2 d 4 0 2 420 0 3 4 50 0 4 3 3

3 3 0 s 7 10 6 4 3

8 0 5

4 3 p 0 1 0 34 0 0 3 1 3 39 3 4 8 0 0 0

0 3 0 a 4 9 7 0 3 90 0 0 3 380 6 0 0 1 0 3 4 8 n r 4 3 u 0

370 7 R R 3 0 2 0 4 1 340 4 0 m 4 8 0 3 0 3 u 0 340 0 4 5 u 3 2 3 4

0 n 0 6 0 d 3 3 5 4 3 0 0 1 8 4 n 0 3 0 35 3 9 50 0 4 3 3 0 4 0 0 u 5 0 8 r 3 3 0 o 0 3 4 3 3 6

6 0 0 7 0

0 8 9 C 0 0 3 0 0 0 0 3 0 36 37 0 1 4 350 4 4 3 6 4

0 1

0 410 380 4 4 0 370 2 0

3 0 0 7 380 0 2 3 0 8 4 3 4 5 3 0 390 0

Xpg 90 3 3 390 8 0 3 0 8 7 380 0 3 0 40

3 9 10 0 4 40 4 0 0 10 40 10 10 Xpg 4 4 380

3 0 9 1 0 0 4 8 3 0 0 2 4 2 4 1 0 4 4 10 4 0 4 0 0 10 1 0 4 0 3 9 0 3 3 4 0 420

1 3 0 9

4 3 4 80

0 3 1

4 2 40 0 0 Trd 4

Map 3. Serpentine grasslands, 1971 UNIONVILLE BARRENS STUDY Feet 1031 Palmers Mill Road, Media, PA 19063 Newlin Township, Chester County, Pennsylvania 0 150 300 610-353-5587 ~ www.natlands.org Compiled By: MTM 12/16/11 3 3 5 6 0 00 0 3 3 10 70 3 3 10 3 0 0 1. 2008 Aerial Photography received from PAMAP Program, PA Unionville1 Barrens Study Area Boundary3 320 0 340 0 4 8 32 0 DCNR (www.pasda.psu.edu). 0 8 3 2. Restoration Study Area and Full Study Area based on 39 33 ChesLen Boundary 0 340 0 330 boundaries 3determined50 by Roger Latham in "Protecting the 4 0 0 00 39 29 Unionville Barrens" (2005). 40 Parcel Boundaries 10 0 40 3 4 30 3 3. Vegetation data derived from NDVI Image Classifications of 3 0 Historical Aerial Photography, 2008 Aerial Photography from 6 41 40 0 310 0 0 32 0 0 Contours (2 ft Interval) 1 0 5 PAMAP Program, 2010 4-Band NAIP Imagery, and LiDAR data. 0 3 35 3 2 0 Xw 3 0 4 9 340 4. Bedrock Geology Boundary and Dikes received from 40 0 3 0 4 0 4 20 38 0 0 0 1 3 3 Pennsylvania Geological Survey from 1980 State Geology Map. 5 6 Waterways 4 0 0 0 0 3 7 0 5 3 3 3 3 5 0 5 0 0 3 3 0 420 41 3 4 3 4 3 9 3 3 8 0 3 7 Disclaimer: This map is not a survey. The information imparted with 0 2 0 0 Open Grassland 1 3 0 3 2 this map is meant to assist Natural Lands Trust, Inc., describe the 0 0 5 0 3 0 0 3 10 20 placement of certain retained, reserved, or excluded rights and to 39 0 3 34 3 KRAMKOWSKI Conifers4 0 38 0 10 1 0 3 calculate acreage figures. Property boundaries, while approximate, 4 36 50 4 Xs 3 were established using the best available information, which may 0 PROPERTY Shorter Woody Vegetation (Trees, Vines, and Shurbs) 330 have included: surveys, tax maps, field mapping using G.P.S.,

0 0 0 5 and/or orthophotos. Natural Lands Trust, Inc., makes no NATURAL LANDS TRUST 40 3 Tallest Vegetation 3 representation as to the accuracy of said property lines (or any 50 4 0 00 4 3 3 5 other lines), and no liability is assumed by reason of reliance 0 (CHESLEN PRESERVE) 3 4 2 3 3 thereon. Use of this map for other than its intended purpose Bedrock Formation Boundary0 9 35 4 3 0 0 0 7 requires the written consent of Natural Lands Trust, Inc. 0 0 0 40 4 3 4 3 2 3 6 3 0 0 7 0 Bedrock3 Dike 0 0 0 4 4

9 4 8 1 3 0 3 0 3 0 3 0 41 31 0

3 8 F Bedrock Formations 0 0 4 430 3 3 6 4 3 3 10 4 0 e 0 4

5 0 3 0 3 3 0 5 3 Serpentinite 8 50 0 400 41 l 3 Xs 0 2 d 4 0 2 420 0 3 4 50 0 4 3 3

3 3 0 s 7 10 6 4 3 8 Schist (Wissahickon Formation) Xw 0 5

4 3 p 0 1 0 34 0 0 3 1 3 39 3 4 8 0 0 0

0 3 0 a 4 Pegmatite dike 9 7 Xpg 0 0 3 39 0 0 380 6 1 80 3 n r 4 3 u 0

Diabase dike 370 7 R R Trd 3 0 2 0 4 1 0 340 4 0 m 4 0 8 4 0 3 0 3 u 0 340 0 4 5 u 3 2 3 4

0 n 0 6 0 d 3 3 5 4 3 0 0 1 8 4 n 0 3 0 35 3 9 50 0 4 3 3 0 4 0 0 u 5 0 8 r 3 3 o 3 3 3 6

6 0 0 7 0

0 8 9 C 0 0 3 0 0 0 0 3 0 36 37 0 1 4 350 4 4 3 6 4

0 1

0 410 380 40 4 4 0 370 2 0 0 3 0 0 7 380 0 2 3 0 8 4 3 4 5 3 0 390 0

Xpg 90 3 3 390 8 0 3 0 8 7 380 0 3 0 40 HECKERT 3 9 10 0 4 40 4 0 0 10 PROPERTY 40 10 10 Xpg 4 4 380

3 0 9 1 0 0 4 8 3 0 0 2 4 2 4 1 0 4 4 10 4 0 4 0 0 10 1 0 4 0 3 9 0 3 3 4 0 420

1 3 0 9

4 3 4 80

0 3 1

4 2 40 0 0 Trd 4

Map 4. Vegetation structure, 2008 UNIONVILLE BARRENS STUDY Feet 1031 Palmers Mill Road, Media, PA 19063 Newlin Township, Chester County, Pennsylvania 0 150 300 610-353-5587 ~ www.natlands.org Compiled By: MTM 12/16/11 3 3 5 6 0 00 0 3 3 10 70 3 3 10 3 0 0 1. 2008 Aerial Photography and Contours (2 ft Interval) received Unionville1 Barrens Study Area Boundary3 320 0 340 0 4 8 32 0 from PAMAP Program, PA DCNR (www.pasda.psu.edu). 0 8 3 2. Unionville Barrens Study Area Boundary determined by Roger ChesLen Boundary 39 33 0 340 0 330 Latham in "Protecting350 the Unionville Barrens" (2005). 4 0 0 00 39 29 3. Vegetation data derived from NDVI Image Classifications of 40 Parcel Boundaries 10 0 40 3 4 30 3 Historical Aerial Photography, 2008 Aerial Photography from 3 0 6 41 40 0 310 PAMAP Program, 2010 4-Band NAIP Imagery, and LiDAR data. 0 0 32 Contours (2 ft Interval) 0 0 380 1 0 5 4. Waterways received from Chester County. 0 3 35 3 2 0 3 0 4 9 340 40 0 3 4 0 4 20 0 0 0 Waterways 1 3 3 Disclaimer: This map is not a survey. The information imparted with 5 6 4 0 0 0 0 3 7 5 3 3 3 3 0 5 0 0 3 this map is meant to assist Natural Lands Trust, Inc., describe the 3 0 420 41 4 3 4 3 9 3 3 8 0 3 7 0 placement of certain retained, reserved, or excluded rights and to 0 2 Successional0 History Groups 3 0 3 1 80 5 3 2 calculate acreage figures. Property boundaries, while approximate, 3 0 0 0 0 0 3 10 20 were established using the best available information, which may 9 3 3 3 Wooded4 since before 1937 3 40 10 have included: surveys, tax maps, field mapping using G.P.S., 350 4 3 and/or orthophotos. Natural Lands Trust, Inc., makes no 0 3 Wooded since between 1937 & 1958 5 33 0 0 3 representation as to the accuracy of said property lines (or any 4 6 0 0 0 0 5 other lines), and no liability is assumed by reason of reliance 40 3 Wooded since between 1958 & 1971 3 thereon. Use of this map for other than its intended purpose 4 50 4 1 0 400 0 3 3 5 requires the written consent of Natural Lands Trust, Inc. 0 3 4 42 Wooded since between2 1971 & 1990 0 0 39 34 3 0 0 7 0 0 0 40 4 3 Wooded since between 1990 & 2010 3 3 0 0 7 3 0 0 4 4

9 4 8 1 3 0 3 0 3 0 3 0 41 31 0

3 8 0 Still grassland in 2010 0 6 F 3 0 4 430 3 3 6 4 3 3 10 4 0 e 0 4

5 0 3 0 3 3 Recent Disturbance 0 5 3 8 50 0 400 41 l 3 0 0 42 2 d 4 0 2 420 0 3 4 50 0 4 3 3

3 3 0 s 7 10 6 4 3

8 0 5

4 3 p 0 1 0 34 0 0 3 1 3 39 3 4 8 0 0 0

0 3 0 a 4 9 7 0 0 3 39 0 0 380 6 1 80 3 n r 4 3 u 0

370 7 R R 3 0 2 0 4 1 0 340 4 0 m 4 0 8 4 0 3 0 3 u 0 340 0 4 5 u 3 2 3 4

0 n 0 6 0 d 3 3 5 4 3 0 0 1 8 4 n 0 3 0 35 3 9 50 0 4 3 3 0 4 0 0 u 5 0 8 r 3 3 o 3 3 3 6

6 0 0 7 0

0 8 9 C 0 0 3 0 0 0 0 3 0 36 37 0 1 4 350 4 4 3 60 410 380 40 4 4 0 370 2 0 3 0 3 0 0 7 380 5 0 2 0 0 8 4

4 3 3 39 0 4 0 0 1 0 0 0 4 39 390 3 8 0 3 0 8 7 380 0 3 0 40

3 9 10 0 4 4 0 41 400 0 0 0 41 410 380 3 9 0 0 8 3 0 0 2 4 2 4 1 0 4 4 10 4 410 0 0 0 1 0 4 0 3 9 0 3 3 4 0 420

1 3 0 9

0 0 1 4 4 410 3 410 0 2 4 0 414 1 440 4 0 3 3 0 2 n 3 450 u 0 0 4 2 4 R 4 4 0 4 0 4 0 0 3 0 4 45 4 e 3 0 n 40 450 4 440 0 i 46 t 4 0 1 450 5 460 0 n 4 0 2 4 50 e 4 4 5 p 0 8 460 0 44 4 4 r 0 46 e 4 0 50 S 0 0 4 0 3 6 0 46 4 3 7 4 0 4 0 00 0 0 4 46 450 370 0 4 47 7 6

4 3 4 80

0 3 1

4 2 40 0 0

Map 5. Grassland succession history, 1937-2010 UNIONVILLE BARRENS STUDY Feet 1031 Palmers Mill Road, Media, PA 19063 Newlin Township, Chester County, Pennsylvania 0 300 610-353-5587 ~ www.natlands.org Compiled By: MTM 12/19/11 3 3 5 6 0 00 0 3 3 10 70 3 3 10 3 1. 2008 Aerial Photography and Contours (2 ft Interval) received Unionville0 Barrens Study Area Boundary 0 1 3 320 0 340 0 4 8 32 0 from PAMAP Program, PA DCNR (www.pasda.psu.edu). 0 8 3 2. Unionville Barrens Study Area Boundary determined by Roger ChesLen Boundary 39 33 0 Latham in "Protecting the 3Unionville40 Barrens"0 (2005). 330 350 4 0 0 3. Maximum soil depth to bedrock and soil sampling points 00 39 29 Parcel Boundaries 40 10 0 40 3 created from soil and GPS data collected by Roger Latham and 4 30 3 3 0 Elizabeth Haegele. Kriging of maximum soil depth to bedrock 6 41 40 0 310 0 0 32 Contours (2 ft Interval) 0 0 value performed by Natural Lands Trust. 380 1 0 5 0 3 35 3 2 0 3 0 4 9 340 4. Waterways received from Chester County. 40 0 3 4 0 4 20 0 0 0 Waterways 1 3 3 5 6 4 0 0 0 0 3 7 5 3 3 3 Disclaimer: This map is not a survey. The information imparted with 3 0 5 0 0 3 3 0 420 41 4 3 4 3 9 3 3 8 0 3 7 this map is meant to assist Natural Lands Trust, Inc., describe the 0 2 Maximum0 Depth to Bedrock (cm) 0 3 0 3 1 80 5 3 2 placement of certain retained, reserved, or excluded rights and to 3 0 0 0 0 calculate acreage figures. Property boundaries, while approximate, 0 3 10 20 6.21 - 17.25 cm 9 3 3 3 4 3 40 were established using the best available information, which may 10 350 4 have included: surveys, tax maps, field mapping using G.P.S., 3 0 3 17.26 - 24.43 cm 5 33 0 0 and/or orthophotos. Natural Lands Trust, Inc., makes no 3 4 6 0 0 0 representation as to the accuracy of said property lines (or any 0 5 0 3 24.44 - 31.6 cm 34 other lines), and no liability is assumed by reason of reliance 4 50 4 1 0 400 0 3 3 5 thereon. Use of this map for other than its intended purpose

0 3 4 42 31.61 - 39.88 cm 2 0 requires the written consent of Natural Lands Trust, Inc. 0 39 34 3 0 0 7 0 0 0 40 4 3 39.89 - 48.71 cm 3 3 0 0 7 3 0 0 4 4

9 4 8 1 3 0 3 0 3 0 3 0 41 31 0

3 0 48.72 - 58.64 cm 8 0 6 F 3 0 4 430 3 3 6 4 3 3 10 4 0 e 0 4

5 0 3 0 3 3 58.65 - 71.89 cm 0 5 3 8 50 0 400 41 l 3 0 0 42 2 d 4 0 2 420 0 3 4 50 0 71.9 - 88.44 cm 4 3 3

3 3 0 s 7 10 6 4 3

8 0 5

4 3 p 0 88.45 - 109.41 cm 1 0 34 0 0 3 1 3 39 3 4 8 0 0 0

0 3 0 a 4 9 7 0 0 3 109.42 - 146.93 cm 39 0 0 380 6 1 80 3 n r 4 3 u 0

370 7 R R 3 0 2 0 4 1 0 340 4 0 m 4 0 8 4 0 3 0 3 u 0 340 0 4 5 u 3 2 3 4

0 n 0 6 0 d 3 3 5 4 3 0 0 1 8 4 n 0 3 0 35 3 9 50 0 4 3 3 0 4 0 0 u 5 0 8 r 3 3 o 3 3 3 6

6 0 0 7 0

0 8 9 C 0 0 3 0 0 0 0 3 0 36 37 0 1 4 350 4 4 3 60 410 380 40 4 4 0 370 2 0 3 0 3 0 0 7 380 5 0 2 0 0 8 4

4 3 3 39 0 4 0 0 1 0 0 0 4 39 390 3 8 0 3 0 8 7 380 0 3 0 40

3 9 10 0 4 4 0 41 400 0 0 0 41 410 380 3 9 0 0 8 3 0 0 2 4 2 4 1 0 4 4 10 4 410 0 0 0 1 0 4 0 3 9 0 3 3 4 0 420

1 3 0 9

4 3 4 80

0 3 1

4 2 40 0 0

Map 6. Estimated soil depth to bedrock UNIONVILLE BARRENS STUDY Feet 1031 Palmers Mill Road, Media, PA 19063 Newlin Township, Chester County, Pennsylvania 0 300 610-353-5587 ~ www.natlands.org Compiled By: MTM 12/19/11 3 3 5 6 0 00 0 3 3 10 70 3 3 10 3 1. 2008 Aerial Photography and Contours (2 ft Interval) received Unionville0 Barrens Study Area Boundary 0 1 3 320 0 340 0 4 8 from PAMAP Program, PA DCNR (www.pasda.psu.edu). 32 0 0 8 2. Unionville Barrens Study Area Boundary determined by Roger 3 ChesLen Boundary 39 33 0 Latham in "Protecting the 3Unionville40 Barrens"0 (2005). 330 350 4 0 0 3. Estimated soil A-horizon thickness and soil sampling points 00 39 29 Parcel Boundaries 40 created from soil and GPS data collected by Roger Latham and 10 0 40 3 4 30 3 3 0 Elizabeth Haegele. Kriging of estimated soil A-horizon thickness 6 41 40 0 310 0 0 32 Contours (2 ft Interval) 0 0 value performed by Natural Lands Trust. 380 1 0 5 0 3 35 3 2 0 4. Waterways received from Chester County. 3 0 4 9 340 40 0 3 4 0 4 20 0 0 0 Waterways 1 3 3 5 6 4 0 0 0 0 3 7 5 Disclaimer: This map is not a survey. The information imparted with 3 3 3 3 0 5 0 0 3 3 0 420 41 4 3 4 3 9 3 3 this map is meant to assist Natural Lands Trust, Inc., describe the 8 0 3 7 0 0 2 A0 Horizon Thickness (cm) 3 0 3 1 placement of certain retained, reserved, or excluded rights and to 80 5 3 2 3 0 0 0 0 calculate acreage figures. Property boundaries, while approximate, 0 3 10 20 2.86 - 3.28 cm 9 3 3 3 4 3 40 were established using the best available information, which may 10 350 4 have included: surveys, tax maps, field mapping using G.P.S., 3 0 3 3.29 - 3.78 cm 5 33 and/or orthophotos. Natural Lands Trust, Inc., makes no 0 0 3 4 6 0 0 0 representation as to the accuracy of said property lines (or any

0 5 3.79 - 4.31 cm 340 3 other lines), and no liability is assumed by reason of reliance 4 50 4 1 0 400 0 thereon. Use of this map for other than its intended purpose 3 3 5

0 3 4 42 requires the written consent of Natural Lands Trust, Inc. 4.32 - 4.76 cm 2 0 0 39 34 3 0 0 7 0 0 0 40 4 3 4.77 - 5.24 cm 3 3 0 0 7 3 0 0 4 4

9 4 8 1 3 0 3 0 3 0 3 0 41 31 0

3 8 0 5.25 - 5.77 cm 6 0 F 3 0 4 430 3 3 6 4 3 3 10 4 0 e 0 4

5 0 3 0 3 3 5.78 - 6.25 cm 0 5 3 8 50 0 400 41 l 3 0 0 42 2 d 4 0 2 420 0 3 4 50 0 6.26 - 6.69 cm 4 3 3

3 3 0 s 7 10 6 4 3

8 0 5

4 3 p 0 6.70 - 7.23 cm 1 0 34 0 0 3 1 3 39 3 4 8 0 0 0

0 3 0 a 4 9 7 0 0 3 7.24 - 9.97 cm 39 0 0 380 6 1 80 3 n r 4 3 u 0

370 7 R R 3 0 2 0 4 1 0 340 4 0 m 4 0 8 4 0 3 0 3 u 0 340 0 4 5 u 3 2 3 4

0 n 0 6 0 d 3 3 5 4 3 0 0 1 8 4 n 0 3 0 35 3 9 50 0 4 3 3 0 4 0 0 u 5 0 8 r 3 3 o 3 3 3 6

6 0 0 7 0

0 8 9 C 0 0 3 0 0 0 0 3 0 36 37 0 1 4 350 4 4 3 60 410 380 40 4 4 0 370 2 0 3 0 3 0 0 7 380 5 0 2 0 0 8 4

4 3 3 39 0 4 0 0 1 0 0 0 4 39 390 3 8 0 3 0 8 7 380 0 3 0 40

3 9 10 0 4 4 0 41 400 0 0 0 41 410 380 3 9 0 0 8 3 0 0 2 4 2 4 1 0 4 4 10 4 410 0 0 0 1 0 4 0 3 9 0 3 3 4 0 420

1 3 0 9

4 3 4 80

0 3 1

4 2 40 0 0

Map 7. Estimated soil A-horizon thickness UNIONVILLE BARRENS STUDY Feet 1031 Palmers Mill Road, Media, PA 19063 Newlin Township, Chester County, Pennsylvania 0 300 610-353-5587 ~ www.natlands.org Compiled By: MTM 12/19/11 3 3 5 6 0 00 0 3 3 10 70 3 3 10 3 Unionville0 Barrens Study Area Boundary 0 1. 2008 Aerial Photography and Contours (2 ft Interval) received 1 3 320 0 340 0 4 8 32 0 from PAMAP Program, PA DCNR (www.pasda.psu.edu). 0 8 3 2. Waterways and Parcel Boundaries received from Chester ChesLen Boundary 39 33 0 340 0 330 County. 350 4 0 0 00 39 29 340 Side-oats

Parcel Boundaries 3 10 0 340 3 Disclaimer: This map is not a survey. The information imparted with 4 30 2 2 0 0 3 0 0 3 this map is meant to assist Natural Lands Trust, Inc., describe the 6 41 4 20 grama 310 0 0 3 4 0 0 0 Contours (2 ft Interval) 380 1 5 placement of certain retained, reserved, or excluded rights and to 0 3 350 3 2 0 3 0 4 9 340 calculate acreage figures. Property boundaries, while approximate,40 0 3 4 0 4 20 0 0 0 1 3 3 were established using the best available information, which may 5 6 Waterways 4 0 0 0 0 3 7 5 3 3 3 3 0 have included: surveys, tax maps, field mapping 5using G.P.S., 0 0 3 Unionville 3 0 420 41 4 3 4 3 9 3 3 8 7 0 and/or orthophotos. Natural Lands Trust, Inc., makes no 0

0 0 3 3 1 5 Wetlands (approximate) 3 3 2 80 5 0 representation as to the accuracy of said property lines (or any 3 0 0 feldspar 0 0 3 0 other lines), and no liability is assumed by reason of reliance 90 31 4 3

1 thereon. Use of this map for other than its intended purpose 0 quarries

jk 4 requires the written consent of Natural Lands Trust, Inc. 3 3 Ì Highly localized rare plants 0 3 4 5 3 3 0 0 0 3 4 6 Side-oats 3 0 0 2 0 0 0 5 Remnants of historical mines 340 3 4 3 50 4 0 grama 1 8 0 40 0 0 3 3 5

0 3 4 42 2 0 0 0 39 34 5 3 3 0 0 7 0 0 0 40 4 3 3 3 0 0 7 3 0 0 4 4

9 4 8 3 1 0 3 0 0 3 4 0 6 3 10 1 3 3 0 0 5 F 3 0 4 430 3 3 6 4 3 3 10 4 0 e 0 4

5 Elliot's 0 0 3 3 4 0 3 8 0 2 4 1 Chandler-Ball 35 0 00 4 l 20 4 d mine pits 420 3 50 0 3 3

3 0 s 7 10 6 4 mine 3

8 0 0 4 p 4 0 1 0 34 0 3 1 3 l 3 4 0 8

0 2 0 0 a 3 Elliot's 8 0 4 9 Bicknell's 3 7 0 3 0 0 4 90 0 3 3 5 380 6 0 3 1 beardgrass 3 n r Elliot's 4 u sedge l

7 R R 3 mine 10 40 4 0 0 3 m 4 0 0 8 4 0 3 0 7 3 u 3 0 5 3 u 3 40 4 pits i 3 0

6 d n 3 50 3 0 1 0 8 4 n 0 3 0 3 3 5 0 9 50 0 4 3 3 0 7 4 0 0 u 5 3 0 8 3 r 0 3 2 o 4 3 3 0 6 6 8

0 3 0 0 9 C 0 3 0 0 0 0 0 36 37 0 1 4 H 4 350 4 3 60 410 380 40 4 4 0 370 2 0 3 0 3 0 7 380 5 0 0 0 8 4 3 3 39 0 4 0 0 1 0 4 0 4 1 390 0 0 3 8 7 380 0 3 0 40

0 9 10 3 4 m 4 400 0 20 41 410

8 4

3 1 Patterson Corundum 0 0 2 4 u 4 1 0 mine 4 Hill 410 0 0 0 41 0 9 33 3 0 serpentine Johnson & 420 d 0 9 3 Patterson's quarry Richardson's

0 0 1 4 4 feldspar sedge 410 3 410 0 n 2 4 0 414 1 440 4 quarries 0 3 3 0 2 n 3 450 u

0 2 R 4 4 u 0 0 4 4 0 0 3 4 50 e 4 4 40 3 4 Elliot's 50 0 n 4 r i 60 0 4 4 t 4 mine 4 1 460 0 n 50 0 4 2 4 50 e 40 4 trenches 0 4 5 460 Bicknell's 4 p r 0 hoary rockrose 46 e Elliot's 4 0 50 S 0 0 4 60 C o 3 6 470 4 4 3 4 0 0 00 mine shafts 0 4 460 450 370 0 4 47 7 6

4 3 4 80

0 3 1

4 2 40 0 0

Map 8. Features of special conservation concern or historical significance UNIONVILLE BARRENS STUDY Feet 1031 Palmers Mill Road, Media, PA 19063 Newlin Township, Chester County, Pennsylvania 0 300 610-353-5587 ~ www.natlands.org Compiled By: MTM 01/03/12 3 3 5 6 0 00 0 3 3 10 70 3 3 10 3 0 0 1. 2008 Aerial Photography and Contours (2 ft Interval) received ChesLen1 Boundary 3 0 320 0 340 0 4 8 8 32 0 3 from PAMAP Program, PA DCNR (www.pasda.psu.edu). 2. Waterways and Parcel Boundaries received from Chester 3 3 Parcel Boundaries 90 34 30 330 County. 35 0 0 0 4 39 0 00 29 n 40 Contours (2 ft Interval) 10 0 40 3 4 30 3 Disclaimer: This map is not a survey. The information imparted with 38 3 0 u this map is meant to assist Natural Lands Trust, Inc., describe the 6 0 41 40 0 310 0 0 32 Waterways 80 10 0 placement of certain retained, reserved, or excluded rights and to 3 0 R 0 5 0 3 35 3 2 0 0 3 0 4 9 3 340 calculate acreage figures. Property boundaries, while approximate,40 0 4 3 4 20 0 10 3 40 were established using the best available information, which may 5 Existing Wide Trail 6 4 0 0 3 0 0 3 7 5 3 3 3 3 m have included: surveys, tax maps, field mapping 5using G.P.S., 0 0 3 3 0 420 41 4 3 9 3

0 3 7 and/or orthophotos. Natural Lands Trust, Inc., makes no 0 2 0 u 3 0 Existing Narrow Footpath 3 1 80 5 3 2 representation as to the accuracy of said property lines (or any 3 0 0 0 d 0 0 3 10 20 other lines), and no liability is assumed by reason of reliance 9 3 3 3 Existing4 Footpath to be Widened 3 40 10 n thereon. Use of this map for other than its intended purpose 350 4 3 requires the written consent of Natural Lands Trust, Inc. 0 3 Potential Firebreak/Wide4 Trail 5 33 u 38 30 0 0 0 4

0 0 r 5 0 3 340 6 3 Potential Footpath 0 4 o 50 0 00 1 4 3 0 5 !!!!!! 3 !!!!!! 0 9 4 C 2 Temporary3 Firebreak0 34 3 0

0 0 34 4 2 37 0 0 0 0 4 4 4 3 4 3 3 1 0 0 0 3 10 41 3 3 0 0 4 3 0 8 0 0 6 F 3 3 0 4 9 3 3 6 4 0 3 3 10 4 0 e 0 4

5 0 3 0 3 3 0 5 3 8 50 0 400 41 l 3 42 0 0 0 d 2 0 5 4 0 2 3 2 4 3 4 50 0 3 3

3 0 s 7 10 6 4 3

4 p 0 1 0 34 0 3 1 3 3 4 8 0 0 0

0 0 a 4 390 7 3 0 4 90 0 0 3 3 380 6 0 0 0 1 0 3 4 4 38 r 9 3 0

370 7 R 3 0 2 0 4 1 50 340 4 0 3 4 8 0 3 0 3 u 0 0 5 3 340 4 2 3 4

0 n 0 6 3 3 4 0 0 1 4 8 0 3 0 350 35 3 9 3 0 4 3 5 0 4 0 0 0 5 0 8 3

3 0 0 0 36 3 4 3 3 6

6 0 0 7 0

0 8 9 0 0 3 0 0 0 3 0 37 0 1 4 350 4 4

4 0 2 41 380 0 0 4 4 0 8 0 3 2 0 3 3 6 370 0 7 3 380 5 0 0 4 3 39 0 4 0 0 1 0 0 0 4 39 390 3 8 0 3 0 8 7 380 0 3 0 40

3 9 10 0 4 4 0 41 00 4 0 0 4 10 410 1 4 0 380 3 9 0 0 8 3 0 0 2 4 2 4 1 0 4 4 410 0 0 0 1 0 4 0 3 9 0 3 3 4 0 420

1 3 0 9

0 0 1 4 4 410 3 410 0 2 4 0 414 1 440 4 0 3 3 0 2 n 3 450 u 0 0 4 2 4 R 4 4 0 4 0 4 0 0 3 0 4 45 4 e 3 0 0 0 n 44 4 45 40 4 i 6 0 t 4 0 1 450 5 460 0 n 4 0 2 4 50 e 4 4 5 p 0 8 460 0 44 4 4 r 0 46 e 4 0 50 S 0 0 4 0 3 6 0 46 4 3 7 4 0 4 0 00 0 0 4 46 450 370 0 4 47 7 6

4 3 4 80

0 3 1

4 2 40 0 0

Map 9. Existing and potential trails, vehicular access and firebreaks UNIONVILLE BARRENS STUDY Feet 1031 Palmers Mill Road, Media, PA 19063 Newlin Township, Chester County, Pennsylvania 0 300 610-353-5587 ~ www.natlands.org Compiled By: MTM 12/19/11 3 3 5 6 0 00 0 3 3 10 70 3 3 10 3 0 0 1. 2008 Aerial Photography and Contours (2 ft Interval) received ChesLen1 Boundary 3 0 320 0 340 0 4 8 8 32 0 3 from PAMAP Program, PA DCNR (www.pasda.psu.edu). 2. Waterways and Parcel Boundaries received from Chester 3 3 Parcel Boundaries 90 34 30 330 County. 35 0 0 0 4 39 0 00 29 n 40 Contours (2 ft Interval) 10 0 40 3 4 30 3 Disclaimer: This map is not a survey. The information imparted with 38 3 0 u this map is meant to assist Natural Lands Trust, Inc., describe the 6 0 41 40 0 310 0 0 32 80 10 0 placement of certain retained, reserved, or excluded rights and to Waterways 3 0 R 0 5 0 3 35 3 2 0 0 3 0 4 9 3 340 calculate acreage figures. Property boundaries, while approximate,40 0 4 3 4 20 0 10 3 40 were established using the best available information, which may 5 Existing Wide Trail 4 6 0 0 3 0 0 3 7 5 3 3 3 3 m have included: surveys, tax maps, field mapping 5using G.P.S., 0 0 3 3 0 420 41 4 3 9 3

0 3 7 and/or orthophotos. Natural Lands Trust, Inc., makes no 0 2 0 u 3 0 Existing Narrow Footpath 3 1 80 5 3 2 representation as to the accuracy of said property lines (or any 3 0 0 0 d 0 0 3 10 20 other lines), and no liability is assumed by reason of reliance 9 3 3 3 Existing4 Footpath to be Widened 3 40 10 n thereon. Use of this map for other than its intended purpose 350 4 3 requires the written consent of Natural Lands Trust, Inc. 0 3 4 5 33 u 3Potential8 Firebreak/Wide30 Trail 0 0 0 4

0 0 r 5 0 3 340 6 3 Potential Footpath 0 4 3 o 50 0 00 1 8 4 3 0 0 5 !!!!!! 3

!!!!!! 9 4 C 2 Temporary3 Firebreak0 39 34 3 0 0

0 0 34 4 2 37 0 Grassland Restoration Target Area 0 0 0 4 4 4 6 4 3 3 3 1 0 0 0 3 10 41 3 3 0 0 4 0 0 6 F 3 0 4 3 3 6 4 3 3 10 4 0 e 0 4

5 0 3 0 3 3 Management Unit Boundary 0 5 3 8 50 0 400 41 l 3 42 0 0 0 d 2 0 5 4 0 2 3 2 4 3 4 50 0 3 3

3 0 s 7 10 6 4 3

!!! p Interim Boundary 4 3 40 1 0 3 0 3 1 3 3 4 8 0 0 0

0 0 a 4 390 7 3 0 4 90 0 0 3 3 380 6 0 0 0 1 0 3 4 4 38 r 9 3 0

4 7 370 R 3 0 2 0 5 4 1 50 340 4 0 3 4 8 0 3 0 3 u 0 0 5 3 340 4 2 3 4

0 n 0 6 3 3 4 0 0 1 4 8 0 3 0 350 35 3 9 3 0 4 3 5 0 4 0 0 0 5 0 8 3

3 0 0 0 36 3 4 3 3 6

6 0 0 7 0

0 8 9 0 0 3 0 0 0 3 0 37 0 1 4 350 4 4

4 0 2 41 380 0 0 4 4 0 8 0 3 2 0 3 3 6 370 0 7 3 380 5 0 0 4 3 39 0 4 0 0 1 0 0 0 4 39 390 3 8 0 3 0 8 7 380 0 3 0 40

3 9 0 4 0 41 00 4 0 0 4 10 410 1 4 0 380 3 9 4 0 0 1 8 0 3 2 0 0 2 4 2 4 1 0 4 4 410 0 0 0 1 0 4 0 3 9 0 3 3 4 0 420

1 3 0 9

0 0 1 4 4 410 3 410 0 1 2 4 0 414 1 440 4 0 3 3 0 2 n 3 450 u 0 0 4 2 4 R 4 4 0 4 0 4 0 0 3 0 4 45 4 e 3 0 0 0 n 44 4 45 40 4 i 6 0 t 4 0 1 450 5 460 0 n 4 0 2 4 50 e 4 4 5 p 0 8 460 0 44 4 4 r 0 46 e 4 0 50 S 0 0 4 0 3 6 0 46 4 3 7 4 0 4 7 0 0 0 0 0 4 46 450 370 0 4 47 7 6

4 3 4 80

0 3 1

4 2 40 0 0

Map 10. Serpentine barrens restoration and management units UNIONVILLE BARRENS STUDY Feet 1031 Palmers Mill Road, Media, PA 19063 Newlin Township, Chester County, Pennsylvania 0 300 610-353-5587 ~ www.natlands.org Compiled By: MTM 12/19/11