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Fen Restoration and Management at Matthaei Botanical Gardens

by

Brad Ruhfel

A practicum submitted in partial fulfillment of the requirements for the degree of Master of Science (Natural Resources and Environment) at the University of August 2005

Faculty advisors: Associate Professor Robert Grese Professor John Witter

Acknowledgements

There are a number of people I would like to thank for their help and encouragement in the completion of this project. First, I would like to thank my advisors Robert Grese and John Witter for their guidance and comments on my work through its many stages. Second, many others helped with the development of my thoughts about this project through conversation, site visits, and help with botanical identification. Included in this group are Tony Reznicek, Melanie Gunn, Burt Barnes, Don Tilton, Doug Wilcox, Barb Madsen, Yu Man Lee, Ray Falhsing, Nate Fuller, Chad Hershock, Sherri Laier, Jack McGowan-Stinski, Glen Palmgren, Doug Pearsall, Mike Penskar, Steve Woods, Bev Walters, Dave Borneman, Brian Klatt, Mike Kost, Gary Hannan, and Jennifer Moore. Third, many of the staff at MBGNA have helped with the varied aspects of this project including: Paul Girard, Connie Bailie, David Michener, Ellen Weatherbee, Mike Hommel, Thom O’Dell, Jim Dickinson, and Jeff Plakke. Thank you. I am certain that I have forgotten someone. If you are among those that I have failed to mention, I apologize. Again, thank you. Finally, I would like to thank my family and my fiancée, Christina Bartoli. These are the people who have sacrificed so much so that I could finish this work and complete my Master’s degree.

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Table of Contents

Abstract……………………………………………………………………………………1 Goals and Justification…………………………………………………………………….3 Chapter 1: Literature Review……………………………………………………………...6 Definition and similarity to other types…………………………………..6 Geographic location……………………………………………………………….7 Occurrence in the landscape………………………………………………………8 Water chemistry…………………………………………………………………...9 Vegetation………………………………………………………………………..11 ……………………………………………………………...... 13 Threats……………………………………………………………………………14 Management strategies…………………………………………...... 19 Conclusion……………………………………………………………………….25 Chapter 2: Site Analysis and Observations………………………………………………27 Introduction………………………………………………………………………27 Methods…………………………………………………………………………..28 Results………………………………………………………...………………….31 Discussion………………………………………………………………………..34 Management recommendations………………………………………………….42 Chapter Three: Kirk’s Restoration and Management Plan………………………….45 Introduction………………………………………………………………………45 Site Description…………………………………………………………………..46 Key Ecosystem Processes………………………………………………………..48 Land Use History and Ecosystem Change……………………………………….49 Conservation Targets…………………………………………………………….50 Stresses…………………………………………………………...... 51 Potential for Success of Restoration……………………………………………..54 Goals, Objectives, and Tasks…………………………………………………….55 Suggested Restoration Strategy………………………………………………….58 Alternative Management…………………………………………………………61 Monitoring……………………………………………………………………….62

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Suggested Further Studies…………………..……………………………………65 Recommended Use………………………………………………………………66 Conclusion……………………………………………………………………….66 Chapter Four: Radrick Fen Management Plan…………………………………………...68 Introduction………………………………………………………………………68 Site Description…………………………………………………………………..69 Key Ecosystem Processes………………………………………………………..71 Land Use History and Ecosystem Change……………………………………….71 Conservation Targets…………………………………………………………….72 Stresses…………………………………………………………...... 73 Potential for Success……………………………………………………………..77 Goals, Objectives, and Tasks…………………………………………………….77 Suggested Management Strategy……………………………...... 80 Alternative Management…………………………………………………………82 Monitoring……………………………………………………………………….82 Suggested Further Studies………………………………………………………..85 Recommended Use………………………………………………………………86 Conclusion……………………………………………………………………….86 Concluding Remarks……………………………………………………………………..88 Appendix A: Threatened and Special Concern Species: Biology and Management Recommendations…………………..………………………...90 Appendix B: Specific Invasive and Problematic Species Management Information……………………………………………………...... 97 Tables…………………………………………………………………………………...109 Figures…………………………………………………………………………………..129 Literature Cited…………………………………………………………………………143

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List of Tables

Table 1. Species typical of prairie fen vegetation zones. ……………………………...109 Table 2. Kirk’s Fen Floristic Quality Analysis data…………………...... 110 Table 3. Species list of vegetation in Kirk’s Fen and associated FQA information for each plant……………………………………………………....111 Table 4. Radrick Fen Floristic Quality Analysis data…………………………………..114 Table 5. Species list of vegetation in Radrick Fen and associated FQA information for each plant…………………………………………...…………115 Table 6a-c. Kirk’s Fen and water table transects…………...………………………119 Table 7a-c. Radrick Fen soil and water table transects………………………………….120 Table 8. Change in graminoid dominated area of Matthaei between 1949 and 2002 as estimated from aerial photographs………………...121 Table 9. Vegetation not found in either Radrick Fen or Kirk’s Fen currently but listed by Bland (1971) as occurring in seepage at Matthaei Botanical Gardens…………………………...... 122 Table 10. Annual timing for restoration and monitoring tasks in Matthaei fens………………………………………………...... ….123 Table 11. Rare plants, insects, and reptiles associated with prairie fens as listed by Spieles et al. (1999) and not currently known in the Matthaei fens……………………………………………………………..124 Table 12. Vegetation not found in Radrick Fen currently, but listed by Wagner (no date) as being present…………………………………………..125 Table 13. Species present in inventory by Reznicek et al. (1999) but not found in inventories for this report…………………………………………126 Table 14. Restrictions on prescribed burning in massasauga taken from Pearsall and McGowan-Stinski (2004)……………………………..127

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List of Figures

Figure 1. Diagram of idealized fen formation in the landscape………………………...129 Figure 2. Locations of the Matthaei Botanical Gardens fens…………………………..131 Figure 3. Placement of transects for soil and water table observations in Kirk’s Fen……………………………………………………………………133 Figure 4. Placement of transects for soil and water table observations in Radrick Fen…………………………………………………………………..135 Figure 5. Graminoid dominated area of fens at Matthaei Botanical Gardens through time as estimated by aerial photograph interpretation……….137 Figure 6. Estimated boundary of graminoid dominated area in Kirk’s Fen from 1949 aerial photograph……………………………………………………139 Figure 7. Estimated boundary of graminoid dominated area in Kirk’s Fen from 2002 aerial photograph……………………………………………………139 Figure 8. Estimated boundary of graminoid dominated area in Radrick Fen from 1949 aerial photograph…………………………………………………...141 Figure 9. Estimated boundary of graminoid dominated area in Kirk’s Fen from 2002 aerial photograph……………………………………………………141

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Abstract

The primary objective of this practicum is to create a restoration and management plan for two prairie fen , Kirk’s Fen and Radrick Fen, at the University of Michigan’s Matthaei Botanical Gardens. Fens are a rare wetland type and are among the most biologically diverse North American wetlands. Kirk’s Fen and Radrick Fen are threatened by shrub encroachment, lack of fire, and establishment of invasive species. Nutrient addition and altered hydrology may also be affecting these sites. Combined these sites contain three state threatened plant species: Cypripedium candidum, Sanguisorba canadensis, and Valeriana ciliata. These fens also support populations of the snake, Sistrurus catenatus catenatus, a state species of special concern. Management activities proposed aim to eliminate invasive species and restore the open areas of to their 1950’s size, while protecting and expanding the populations of the unique species present. A review of literature on fens of the Midwestern United States and their management was conducted to provide relevant background information. To investigate current conditions at each site, general observations were made, a Floristic Quality Analysis (FQA) was performed, and soil and water table levels were described. Aerial photographs also were analyzed to estimate change in open area of each fen due to shrub encroachment from 1949 to 2002. Kirk’s Fen has been seriously invaded by shrubs. FQA results revealed that Kirk’s Fen contained 113 species, with 95 of those native. Mean C was 4.7 and the Floristic Quality Index (FQI) was 46.2. Soil here was a mixture of mineral soil and and the water table was usually within 28 cm of the surface. Peat soil depth was generally greater than 1.7 m. Analyses of aerial photographs revealed that open areas in Kirk’s Fen have decreased by 88%. Radrick Fen is a high quality fen, possibly one of the finest in Southeast Michigan. FQA results revealed that Radrick Fen contains 137 species, with 133 of those native. Mean C is 5.3 and the FQI was 61.4. Soil here was hemic to fibric peat and the water table was predominantly at the surface. Peat soil depth ranged from 1.2 m to greater than 1.7 m. Analyses of aerial photographs revealed that open areas in Radrick Fen have decreased by 33%. Both fens contain populations of invasive species known to be problematic in fens.

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Recommendations include removal of shrubs by cutting and herbicide application. Herbaceous invasive species should be removed by a combination of hand-removal and herbicide application. Prescribed fire should be used to maintain and expand open areas of the fens while promoting native vegetation. Monitoring should be conducted on the results of management activities, with special emphasis on the threatened and special concern species.

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Goals and Justification

The goal of this Master’s practicum is to create a restoration and management plan for two fen wetlands at the University of Michigan’s Matthaei Botanical Gardens, hereafter referred to as Matthaei. This plan will provide suggestions to maintain and improve the current high quality conditions of Radrick Fen and to restore the original size and quality of Kirk’s Fen; historically this area was known as Kirk’s . Here the more correct moniker, Kirk’s Fen, will be used as bog is an inappropriate term to describe this wetland. If implemented, this plan will help protect and expand these wetlands as well as the populations of three state threatened plant species and one state snake species of special concern currently being considered for federal listing. Presently no comprehensive plan exists for these sites. To guide the development of this plan a review of relevant literature and a description of current conditions and recent changes at the fens were conducted. This information will also be pertinent to future research conducted at these sites. The contents of this report are divided into three main sections: the literature review, the investigation of site conditions, and the management plans. The literature review focused on temperate fens of the Midwestern United States and their management. Due to a scarcity of this topic in the literature, information was also drawn from literature concerning similar ecosystems or management situations. To investigate current conditions at each site, general observations were made, a Floristic Quality Analysis (FQA) was performed, and soil and water table levels were described. Aerial photographs were also analyzed to estimate change in open area of each fen due to shrub encroachment from 1949 to 2002. The management plans incorporate information from the literature review and current site conditions sections and make management recommendations based on this information. Details specific to the Matthaei fens are included in this section including land-use history, a review of the biology and management requirements of the threatened and special concern species present, and removal techniques for the invasive species present. Justification for this practicum lies in the rarity of fen wetlands and the lack of knowledge concerning their management. Fens are a rare wetland type throughout Michigan (Spieles et al. 1999) as well as the temperate zone of the United States (Amon 3

et al. 2002) and North America (Eggers and Reed 1997). They are also among the most biologically diverse North American wetlands (Amon et al. 2002) and contain “a disproportionate number of rare, threatened, and endangered plant species as compared to other plant communities in the Great Lakes Region” (Eggers and Reed 1997). Aside from vascular plants, fens support rare bryophytes, mammals, reptiles, land snails, and insects (Bedford and Godwin 2003). Prairie fens, a subclass of fen and the type found at Matthaei, are found only in the glaciated Midwest and have declined in number since European-settlement (Spieles et al. 1999). This fact necessitates implementation of management and conservation techniques to protect these unique wetlands and the species that depend on them. Indeed, active management of fens is becoming more common. However, literature on management techniques specific to fens and its effects on fen flora and fauna is relatively scarce. Research on the effects of these management techniques is needed to provide land managers with sound evidence on which to base their decisions. This report will assist Matthaei and other agencies in making informed decisions about management of these wetlands. Protection of Matthaei fens is important not only because of their rarity, but also because three state threatened plant species occur there (Cypripedium candidum, Sanguisorba canadensis, and Valeriana ciliata) as well as the snake, Sistrurus catenatus catenatus. This snake is a state species of special concern and is being considered for federal protection status. Several other rare plants and animals are associated with prairie fens (Spieles et al. 1999) and while not known to be found at the Matthaei fens presently, these wetlands may be important in the future as possible dispersal locations or sites for reintroduction. As these fens are managed, future inventories may reveal the presence of rare flora and fauna so far unrecorded. The most imminent threat to the Matthaei fens is invasion by woody species. Both Radrick and Kirk’s Fens have decreased in size over the past decades due to encroachment of invasive Rhamnus spp. Eggers and Reed (1997) note that without control, Rhamnus spp. can form dense thickets in fens that will shade out fen plant species, including rare species, found there. With the decrease in size of functional prairie fen habitat at Matthaei, the ability of these sites to maintain greater levels of diversity may be impaired. Hoffhines and Nepstad (1980) found that larger fens contain more plant species than smaller fens. Likely, there would be similar results for fauna 4 reliant on this habitat type. The combined effects of Rhamnus spp. invasion- shading out native vegetation and the reduction in size of suitable fen habitat for flora and fauna- produce a situation where management is essential for the survival of both the ecosystem type and species that require it to survive.

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Chapter 1: Literature Review

Definition and similarity to other wetland types

The definition of what a “fen” is changes depending on where you are and who you ask, though most sources agree on the importance of groundwater in their formation. In this review we will follow this definition: fens are a type of wetland whose vegetation, water chemistry, and soil development are determined by groundwater flow. This distinguishes them from other wetlands types that are supplied with water either through precipitation, as in the case of bogs, or surface water input, as in the case of and (Bedford and Godwin 2003). Midwestern temperate zone fens in particular have a unique set of characteristics and will be the focus of this review. As defined by Amon et al. (2002) they are: 1) groundwater dependent, with the groundwater moving through the root zone and maintaining saturation through most of the year; 2) are not frequently inundated; 3) tend to accumulate carbon in their substrates; and 4) are dominated by nonemergent graminoid vegetation. Certain Midwestern fens have an internal flow of groundwater rich in calcium and magnesium bicarbonates (Eggers and Reed 1997) and have been termed calcareous or rich fens because of this trait. However, Amon et al. (2002) warn that the term “rich fen” may lead to the incorrect assumption that these wetlands are high in growth limiting nutrients, such as nitrogen and phosphorus, which are usually low in quantity. It should be noted that not all groundwater fed wetlands will be calcareous. Groundwater moving through sand or iron sulfate-rich material will have a pH lower than 5.5 and support different vegetation than calcareous fens (Bedford and Godwin 2003). A specific type of calcareous fen, and that found at Matthaei, is the prairie fen. This type differs from other calcareous fens by the presence of a tall grass prairie flora and fauna component (Spieles et al. 1999). The confusion in defining fens results from the ability of one wetland type to transition into another, both spatially and temporally, and the basis on which the is made. Spatially, fens can transition into shrub carrs, wet prairies, sedge meadows, marshes, and lakes (Amon et al. 2002) and are considered similar to bogs and interdunal wetlands (Spieles et al. 1999). Temporally, fens can be succeeded by bogs or coniferous swamps (Crum 1988). Classification of fens has been by water chemistry, 6

vegetation, hydrology, topography, ontogeny, and even peat characteristics, amongst others (Mitsch and Gosselink 2000). Generally in the Midwest, classification is by water chemistry and vegetation. Many names have been applied to Midwestern fens because of different classification schemes. These include: calcareous fens, seepage fens, prairie fens, boreal fens, slope marshes, fens, raised bogs, hanging bogs, spring fens, rich fens, and poor fens just to name a few. These differences in nomenclature and classification should be taken into account when reading the literature and comparing one fen to another. Crum (1988) said it best, “the kinds of wetlands can scarcely be compartmentalized and labeled. No two of them are exactly alike.”

Geographic location

Fens occur throughout North America in both the temperate and boreal zones, though temperate zone fens are viewed to be distinct from those in the boreal zone by differences in vegetation, water availability, typical size, and soil (Amon et al. 2002, Curtis 1971). In northern regions of the Midwest, boreal fens occupy large areas. Temperate zone fens on the other hand, occupy a much smaller portion of the landscape, with most ranging in size from a few to several hectares (Bedford and Godwin 2003). Many agree that temperate zone fens are among the rarest and most biologically diverse wetland types (Eggers and Reed 1997, Amon et al. 2002) with prairie fens being rarer still (Spieles et al. 1999). Prairie fens are limited to the glaciated Midwest and in Michigan occur only in the southern third of the Lower Peninsula. Currently the Michigan Natural features inventory recognizes 120 fens of this type in Michigan totaling about 2000 ha (Spieles et al. 1999). The status of fens in the presettlement landscape is not well known, though they are expected to have declined in number and quality. One report from Iowa states that fifty years ago 2333 fens were present and currently only 160 remain; of these most were small and disturbed (Bedford and Godwin 2003). Presettlement vegetation maps of Michigan do not list fens specifically though they are likely grouped with wet prairie or categories (Spieles et al. 1999). Current statistics on national distribution and quality of remaining fens are difficult to discern as the National Wetlands Inventory Classification does not identify fens specifically (Cowardin et al. 1979). 7

Occurrence in the landscape

The development of fens in the landscape is determined by an interaction of climate, physiography, geology, and hydrology which in turn determine the water chemistry, vegetation, and soil development of the fen. In general the summers of the temperate Midwest are characterized by greater evapotranspiration potential than precipitation, leading to a growing season water deficit (Amon et al. 2002). Fens can develop only where groundwater continuously saturates soil at the surface (Bedford and Godwin 2003) and as evapotranspiration is greater than precipitation, the placement of fens in the landscape depends on specific local physiographic, geologic, and hydrologic requirements. Physiographic and geologic factors control the movement and chemistry of groundwater and the conditions that force it to the surface. These factors include: 1) surface topography; 2) slope of the land surface; 3) stratigraphy and hydraulic properties of soils, surficial geologic deposits, and bedrock within the watershed and underlying the fen; 4) mineralogy of the soils, surficial geologic deposits, and bedrock within the watershed and underlying the fen; 5) the area of the wetland relative to the area of the watershed; and 6) the flow-path length of groundwater before it reaches the wetland (Bedford and Godwin 2003). As previously stated, Midwestern fens are located in a landscape heavily affected by glaciation. Fens in a glaciated landscape can form in two ways (Fig. 1). First, groundwater in a soil with greater conductivity is prevented further downward movement by a less permeable unit situated below. Groundwater is then forced laterally and discharged on the slope of a hill or near a lake edge. Second a break may occur in an impermeable layer of soil, such as clay, with a high water pressure beneath it and cause focused discharge of water at the surface (Amon et al. 2002). Prairie fens often occur where outwash plain and moraine intersect, generally on the lower slope of the moraine near rivers, lakes, or streams (Spieles et al. 1999). Water levels in a fen are important in both vegetation and soil development and are determined by the same factors contributing to a fen’s development in the landscape: climate, physiography, geology, and hydrology. Fens do not experience the wide range of seasonal and annual variation of water levels typical of other wetland types (Mitsch and Gosselink 2000). This lack of fluctuation is due to relatively constant groundwater 8 input, causing water levels to remain at the soil surface, with soils being saturated but rarely flooded (Amon et al 2002, Bedford and Godwin 2003). In fact, saturation of the root zone in the growing season may control the boundaries of fen habitat and contributes to peat soil development by the anaerobic conditions this develops (Amon et al. 2002). Lowering of the water level will contribute to higher peat decomposition; conversely, excessive discharge will limit accumulation by continuously eroding the soil (Amon et al. 2002). Constant levels are maintained if the wetland is fed by an intermediate or regional groundwater system; however, if the fen is fed by a local system the level may drop during sustained drought (Bedford and Godwin 2003). Amon et al. (2002) report a related reason for dropping water levels: high evaporation rates and a small size of the recharge area. Annually, water levels in fens are reported by Amon et al. to not drop more than 75 cm below the surface, except in transitional areas, such as the uphill or downhill edges of the fen, or near physical features that may drain the area, such as creeks or human constructed features. They also report that water level discharge in different fens is variable, with high levels of discharge forming spring or sheet flow and some fens not discharging water at all. Bedford and Godwin (2003) discuss effects of repeated flooding on a fen. They state repeated flooding would change the chemical and physical properties of the wetland. Frequent flooding would increase nutrients and sediments, resulting in an increase in biomass and a reduction in species diversity; species intolerant of flooding would also be eliminated, further reducing diversity. With changes in vegetation patterns, faunal habitat use would also change (Bedford and Godwin 2003). Not only is the amount of water that flows through fens important but also the chemical properties as determined by the material the water flows through before entering the wetland.

Water chemistry

Fen water chemistry is determined by the geology of the surrounding area. In the Midwest bedrock is typically limestone and dolomite. Groundwater moves through or over bedrock and soils derived from this parent material and is enriched with calcium, magnesium, and bicarbonate before it enters a fen (Wilcox et al. 1986). In turn these minerals affect pH, conductivity, nutrient availability, and cation exchange capacity. The 9

pH and conductivity of fens is higher than bogs and is often used to distinguish between the two. Other similar wetland types may have pH and conductivity readings close to those of fens and thus these measurements have limited ability to distinguish one wetland type from another. Fens also have moderate to high levels of dissolved cations (Amon et al. 2002). Availability of the nutrients nitrogen, phosphorus, and potassium is typically low in these wetlands (Crum 1988) unless enriched by human activities (Bedford and Godwin 2003). Large amounts of nitrogen are present in peat deposits. However, anaerobic conditions inhibit decomposition of peat and the subsequent release of nitrogen contained within (Crum 1988). Crum also states that bacterial organisms responsible for nitrification and nitrogen fixation are absent in waterlogged peat. A study at Ives Road Fen (Jones 1992) revealed the wetland functions as a nutrient sink for nitrogen and carbon as they are immobilized in the undecomposed peat. Phosphorus availability is limited as the input of mineral rich groundwater causes adsorbtion or precipitation of phosphorus out of solution in unavailable forms (Bedford and Godwin 2003). Another avenue of nutrient loss is leaching; potassium and phosphorus are often removed through this process (Crum 1988). The presence of carnivorous plants in these wetlands is one further sign of the lack of available nutrients. Some functions fens perform in the landscape are related to their water chemistry. Bedford and Godwin (2003) suggest that fens help maintain stream water quality through phosphorus sorption and denitrification. As previously mentioned, phosphorus is removed from available pools because the groundwater is high in pH and rich in calcium. They also state that if nitrogen from an external source is present in surface runoff, then anaerobic conditions in the fen and the high carbon content will help promote denitrification before the nutrients reach the water body. Additional functions unrelated to water chemistry include sediment trapping, flood and storm water retention, and wildlife habitat and food source (Eggers and Reed 1997). Nutrients are however not totally absent from the wetland and can enter the fen through rainfall, snowmelt, surface rivulets of water, and deer trails (Crum 1988). Their presence is also dependent on the plant material that composes the peat soil, with sedge peat typical of fens being more nutrient rich than sphagnum peat typical of bogs and poorer fens (Crum 1988). Nutrient availability is also greater on the down-slope edge of 10 a fen where nutrients and sediments accumulate more readily. This may account for differences is growth and composition of the plant community (Amon et al. 2002). Nutrient availability as well as pH, minerals, and cation exchange capacity largely determine the productivity and type of vegetation found in fens (Mitsch and Gosselink 2000). Bedford and Godwin (2003) also state that the unique vegetation and high diversity can be attributed to the low availability of nutrients and the higher pH typical of Midwestern fens. The interrelationship between groundwater chemical composition, the vegetation that grows in these wetlands, and the soils that develop under these conditions is complex and should not be understated.

Vegetation

Fen vegetation contains a high amount of diversity and is known for the many more rare plants that occur in this wetland type compared to other communities of this region (Eggers and Reed 1997). Vegetation is the most easily observed feature of fens and is often used to define them (Amon et al. 2002). However, it should be noted that the vegetation present is due to the unique hydrology and water chemistry discussed previously. Indicator species, or plants that are only found in fens, are often used to define fen habitat. There is difficulty in assigning indicator species to all but the most local levels. This difficulty arises from the fact that many species present are wetland generalists and many of the rare species are very limited in their range. Also, species found in fens in one region of the country may occur in a totally different ecosystem in another region (Amon et al. 2002). In an analysis of fens in , Curtis (1971) found eight plant families made up 50% of species found in these wetlands: Asteraceae (17.4%), Poaceae (8.7%), Lamiaceae (5.2%), Cyperaceae (4.3%), Apiaceae (4.3%), Scrophulariaceae (4.3%), Salicaceae (3.5%), and Rosaceae (3.5%). Plant species present are mainly calciphiles, or plants having an affinity for calcium rich sites (Bedford and Godwin 2003). In addition to vascular plants, bryophytes, including many rare species are present here (Bedford and Godwin 2003). Crum (1988) suggests that the mosses are actually a better indicator of habitat than vascular plants. The Amblystegiaceae, or brown mosses, are more often associated with fens then the Sphagnaceae (Amon et al. 2002). However, Crum (1988) notes that there are species of sphagnum such as 11

Sphagnum warnstorfii and S. fuscum, as well as others, which are found in calcareous fens. Sphagnum spp. are found in mounds, or hummocks, above the reach of the mineral rich groundwater where the leaching action of rain water (Amon et al. 2002) and their own ability to modify the pH of their surroundings creates suitable habitat (Crum 1988). Crum notes that these mounds often begin formation around the bases of shrubs or sedges. High plant species diversity levels have been attributed to two factors (Amon et al. 2002). First, fen conditions permit colonization by a wide range of species or do not select against many species. Second, low nutrient levels characteristic of these wetlands do not allow for the dominance of one or more species. Other factors influencing diversity levels of individual fens include distance from other fens and size. Isolation is reported to be a significant factor of species richness, contributing to lower immigration rates and lower recolonization of species after local extinction (Bedford and Godwin 2003). Size is also important in maintaining species diversity. Larger fens have greater numbers of species when compared to smaller fens. This may be attributed to the larger target area for colonization of new species, or that larger areas may contain more diverse microsite variation providing more suitable locations for survival and reproduction of dispersing propagules (Hoffhines and Nepstad 1980). One study reports that the highest levels of diversity within an individual fen were found in the herb layer in transition from open to forested fen and maximum richness was found near the transition from forested fen to upland (Jacobson et al. 1991). Species densities are very high in fens. Fen plots have been recorded to contain densities of 42 species per m2 of vascular plants and bryophytes, and commonly reach numbers from 20 to 25 per m2. These numbers place fens among the few in the world to support densities this magnitude (Bedford and Goldwin 2003). Prairie fen vegetation is comprised of obligate wetland species, calciphiles, and also tall grass prairie and sedge meadow species and is present in distinct zones (Spieles et al.1999). The vegetation zones of prairie fens are: inundated flat, sedge meadow, calcareous seeps, and wooded fen (Spieles et al. 1999). Inundated flats are located around lakes or streams and standing water can be present in the spring. The sedge meadow zone is the most characteristic and largest portion of prairie fens and is saturated but not inundated with water. Diversity is greatest in this zone and is comprised mostly 12

of sedges, grasses, shrubs, and composites. Calcareous seeps are present in some fens where discharge is great and calcium carbonate accumulates at the surface (Miner and Ketterling 2003). These areas can be large or small and are often sparsely vegetated with calciphiles. The wooded fen zone can either surround the fen on the upland edges or be present in the lower wetter areas. This zone is often similar in species composition to a deciduous . Species typical for each zone of prairie fens in Michigan are listed in Table 1. Prairie fens were part of a complex of ecosystems maintained by fire in presettlement times. Second to their unique hydrology, fire was a main factor in maintaining their open structure by inhibiting shrub invasion (Curtis 1971). Fires started in the upland oak savannahs, barrens, and prairies by Native Americans or lightning then spread to the fens and burned surface vegetation (Spieles et al. 1999). The prairie component to the vegetation may in fact be due to this presettlement fire regime (T. Reznicek, pers. comm.). The interplay of water levels and fire frequency is likely to determine the ability of woody species to invade fens. In a study in Northern Maine, a period of frequent fires with low water levels allowed the invasion of trees into all but the wettest portions of a fen. When fire was then absent and the water levels were still low, trees then invaded the central, wetter portion (Jacobson et al. 1991).

Soils

Fens are often referred to as peatlands for an obvious reason, their soil is primarily peat, or partially decomposed plant material. This soil type can occur only when plant growth exceeds decomposition (Crum 1988). In Midwestern fens the peat is composed of sedge material in contrast with bogs whose peat is mainly sphagnum. The degree of decomposition of peat varies between fens from fibric to sapric with the latter being more common. Often a mixture of peat in various stages of decomposition is found within a single fen (Amon et al. 2002). In prairie fens peat soil is typically sapric with a depth of 0.5 m to greater than 12 m with a pH of 6.8 to 8.2 (Spieles et al. 1999). Sapric soils may indicate a limitation in water availability at the site. This can be caused by many factors including human drainage in or near the site, reduced amount of water entering the recharge area, or natural changes in water availability, all of which may lead 13

to a lowered water table allowing greater decomposition (Amon et al. 2002). In addition to peat, fen soils may have a mineral component from off-site sources. This may be deposited by wind, upslope erosion of mineral deposits, or the deposition of mineral soil in flood events. Often sites with off-site mineral deposits have complex soil profiles; layers of peat with varying levels of decomposition are mixed with layers of silt and sand (Amon et al. 2002). Calcium carbonate may also be present as a mineral constituent in fen soils as marl or tufa. Marl is an unconsolidated deposit; tufa is consolidated and is the result of evaporation (Amon et al. 2002). Marl flats, areas of non-peat substrate, may form in regions of a fen with high amounts of groundwater discharge. Here precipitated calcium carbonate accumulates as discharging water equilibrates with atmospheric temperature and pressure. It is suspected the presence of Charra spp., as well as the activity of microorganisms, contributes to calcium carbonate precipitation (Miner and Ketterling 2003). A layer of marl beneath a surface of sapric peat may indicate water levels were once higher than the current level, or simply the ease of which water flows through a lower layer of fibric peat compared to sapric peat (Amon et al. 2002).

Threats

Changes in certain aspects of an ecosystem can have far reaching deleterious effects. As a result of these changes a high quality presettlement area, with a representative combination of native biodiversity and intact ecosystem functions, may be degraded into a low quality area lacking its native species composition and previous landscape functions. These threats will vary depending on the specific ecosystem type, but in a fen these include altered hydrology, nutrient addition, fire suppression, and introduction of invasive species. In fact these threats and their effects often are positively reinforcing with the result that one change can intensify the effect of another. Altered hydrology through anthropogenic landscape alteration is a main cause of fen degradation and may lead to changes in nutrient input and vegetation. Hydrology may be altered by changes in groundwater levels or in the ratio of groundwater to surface water input. Spiels et al. (1999) consider hydrology “most important in the maintenance of vegetative structure in prairie fens.” This group reports that level and flow of groundwater in fens can be altered by drains meant to convert the wetland to agricultural 14

use or through groundwater extraction by nearby wells. Quarrying activities can also affect groundwater flow (Bedford and Godwin 2003). Lack of recharge to the water table would change the amount of flow to the fen and may occur through draining of surface water (Spieles et al 1999), or the inability of water to pass through impervious surfaces such as roads and concrete. Spieles et al. (1999) report disrupted recharge areas of many prairie fens has led to their transition from open fen to shrub car. This additional growth of woody plants has been shown to further lower the water table, possibly through transpiration and canopy interception (Jacobson et al. 1991). Fens are mainly groundwater fed and small changes in the ratio of surface water input to groundwater input have been shown to create large changes in pH (Glaser 1990). These changes in pH can then have effects on nutrient availability and plant establishment and reproduction. In fact, small changes in water chemistry have been linked to vegetation response in a peatland (McNamara et al. 1992). Uplands surrounding the fen in a natural state, such as woodlands and prairies, will allow precipitation to recharge the groundwater zone. However, human altered landscapes, agricultural fields, lawns, and impervious surfaces, cause greater inputs of surface water containing sediments and nutrients (Spieles et al. 1999). Human caused nutrient addition to fens can occur through faulty septic tanks and fields (Panno et al. 1999) and agricultural runoff, (Drexler and Bedford 2002). Nutrients may reach the fen through groundwater, surface water, precipitation, and dry deposition (Drexler and Bedford 2002). Panno et al. (1999) suspect that excess nutrients supplied through septic leakage leads to the dominance of invasives including those deemed large threats to fens: Typha angustifolia, Lythrum salicaria, and Phragmites australis. Green and Galatowitsch (2002) also report nutrient enrichment may lead to declines in species richness and lead to dominance by invasives. A study of a fen near a farm field by Drexler and Bedford (2002) reveals that phosphorus and potassium from the farm reached the fen in surface water flow, whereas nitrogen traveled in the groundwater. The same study found a negative impact on the diversity of bryophytes and vascular plants in reaction to this nutrient addition, and as distance from the farm increased, diversity levels rose. In the areas closest to this field, the structure of vegetation was altered, with large monotypic stands of vegetation present compared to the more diverse vegetation elsewhere. The authors suspect that diversity is decreased by nutrient addition through 15 greater competition and productivity of a small number of plants that crowd and shade out smaller, less competitive species. Deer trails also provide nutrient pathways into fens (Crum 1988) and a large amount of deer in an area may contribute to greater levels of nutrient addition. Fire suppression since European settlement is also a threat to the structure of vegetation in Midwestern fens. As previously stated, prairie fens were historically maintained by fires started in the uplands by lighting or Native Americans. Stratigraphic studies have also revealed evidence of fires in peatland development (Crum 1988). These fires have been attributed to maintaining the characteristic open structure of fens by inhibiting invasion by shrubs, both native and invasive (Spieles et al. 1999). Supporting this claim, Jacobson et al. (1991) show that the elimination of fires caused by trains allowed the expansion of woody plant taxa over a fen in Maine. They also observed that the invasion of woody plants will cause the fen to be less able to burn due to lack of fuel build up underneath the trees and shrubs. Crum (1988) notes that shrubs rooted in hummocks of peat survived superficial burns, but that more severe burns that destroyed these hummocks caused a reversion to sedge fen or even standing water. Crum views peatland succession as cyclical because of disturbances, not only fire, but drought, flooding, wind throw, and disease. As situations arise that allow woody plants to invade the fen, disturbances such as fire set back this invasion and keep the fen an open graminoid dominated community. Thus, suppression of natural disturbance will alter the structure of these unique wetlands. Invasive species introduced into a fen can have a wide range of effects including: alteration of habitat structure, lowered biodiversity, changes in number and quality of species, altered nutrient cycling, increased productivity, and modified food webs (Zedler and Kercher 2004). Invasives can also change fuel properties in an ecosystem resulting in altered fire behavior and frequency (Brooks et al. 2004) if fire is allowed to occur at all. Among the more problematic species affecting fens in the Midwest are Rhamnus frangula, Rhamnus cathartica, Phalaris arundinacea, Lythrum salicaria, and Phragmites australis. Often these invaders form monocultures that out compete native plants for nutrients and alter the habitat structure by shading out low-growing, sun-loving species. Rhamnus frangula, a shrub or small tree, is considered a threat to prairie fens as it can establish monocultures in the wooded areas of a fen and can encroach into the sedge 16

meadow zone (Spieles et al 1999). In a study of vegetation response to invasion of Rhamnus frangula in a riparian area, herbaceous species cover was lower and species dominance was altered due to shading (Possessky and Williams 2000). Data from upland forests seem to reinforce the negative aspects of R. frangula on ecosystem structure and composition. Specific effects included lowered seedling density, herbaceous cover, and species richness (Frappier et al. 2003a). Fagan and Peart (2004) also observed that R. frangula reduced the survival of sapling species and altered abundance in favor of more shade tolerant species. In a separate forest study removal of adult R. frangula caused a large increase in the number of R. frangula seedlings in the following year. However, the second year did not see this increase, perhaps because the seed bank was somewhat exhausted (Frappier 2004). This species has been observed to expand at an average rate of 6.7 m per year in an upland forest with the rate of spread being slower in initial stages and increasing as time progressed (Frappier 2003). A related species that tends to have similar behavior to R. frangula in drier upland sites is Rhamnus cathartica. Heneghan et al. (2004) found its leaves decompose rapidly and enrich the soil with nitrogen possibly helping to maintain its dominance; pH was also found to be higher underneath these shrubs. They suggest soil food webs and nutrient cycling may be affected by this addition and that restoration projects in areas once dominated by R. cathartica may need to examine the nutrient levels in the soil. If nitrogen levels are found to be high this could prove detrimental to restoration of native vegetation. R. frangula may have similar effects on fen soils. Although these examples of Rhamnus spp. effects on upland forests may not be directly paralleled in fens, they are likely similar and provide valuable examples of these shrubs effects on a wetland. The perennial grass Phalaris arundinacea is a major invader of temperate wetlands creating monotypic stands and displacing native vegetation (Lindig-Cisneros and Zedler 2002). It reduces wetland diversity, as well as reducing above and below ground biomass of native species (Green and Galatowitsch 2002). Kercher et al. (2004) found that P. arundinacea reduced richness, diversity, and quality of species in a Wisconsin wetland. It is suggested that this species be removed before starting restoration projects as invasions have prevented establishment of sedge meadow vegetation in the Midwest (Perry and Galatowitsch 2004). Another suggestion in the restoration of wetlands dealing with the possible invasion by P. arundinacea is to quickly 17

develop a tall canopy cover of native species as sites with thin vegetative cover are often more susceptible to invasion by this species. Seed mixes that will provide a number of canopy levels are also suggested as many levels of canopy are more resistant to invasion (Lindig-Cisneros and Zedler 2002). P. arundinacea is more competitive and therefore more likely to gain dominance in habitats artificially enriched with nutrients. Greenhouse experiments using carbon enrichment to reduce nitrogen content in the soils have allowed a native sedge species to out compete P. arundinacea. However, applying carbon in the field in amounts necessary to control nitrogen levels may be prohibitive (Perry et al. 2004). Lythrum salicaria is a well known invader of wetlands in the Midwest and nutrient enriched conditions may lead to its dominance (Pano et al. 1999). Its ability to produce copious amounts of seed has allowed this species to spread nearly everywhere in this region. Along with R. frangula, it is noted by Spieles et al. (1999) to be a frequent invader of prairie fens, establishing in the sedge meadow zone. It is also likely to reduce species richness in wetlands. In a study of the response of vegetation to the decline of L. salicaria from beetle attack, species richness rose (Albright et al. 2004). Physical disturbances, such as mowing and trampling, may create favorable environments for the establishment of this species (Choi and Bury 2003) and should be avoided. High populations of deer and the trampling they cause in a fen may also create these favorable situations for establishment. Zedler and Kercher (2004) propose that L. salicaria may reduce pollination and seed production in native species. Phragmites australis, a grass, has similar effects as the previous species listed. Species abundance was reduced by its presence in a Massachusetts fen (Richburg 2001). A study on P. australis in Radrick Fen at Matthaei revealed native plant biomass was reduced in its presence and plants found in high quality areas were less frequent in invaded areas (Gladwin 2003). This species may become dominant in nutrient enriched fens (Pano et al. 1999)

18

Management strategies

Current practices to restore fens in the Midwest and particularly in Michigan involve restoration of hydrology, removal of invasive species, prescribed fire, and planting with seed or more well-developed plant material. Investigations of a site in Maine suggest that management of fens to maintain species richness and rare plants should promote variation of canopy structure by patchy cutting and burning to maintain open, semi-open, and forested portions of the wetland (Jacobson et al. 1991). Summer mowing is also a possibility in managing vegetation and has been shown to increase species diversity (Rowell and Harvey 1985). However, a separate study showed that mowing did not reduce woody material and also increased flowering of invasive species (Clark and Wilson 2001). Negative factors associated with mowing include: compaction of the soil, increased opportunities for colonization by invasives because of soil disturbance, and threat to rare animal species present at these sites. Restoration of hydrology is an important consideration in fen restoration as this is the main factor behind fen formation and presence in the landscape. Hydrology can be restored by filling drainage ditches and by breaking or removing drainage tiles. Drainage ditches can also be dammed at periodic intervals using tongue and groove boards to aid in the raising of water levels (Woods 2003). The removal of tiles has been a successful strategy to restore the water table at Ives Road Fen in Southeast Michigan (D. Tilton pers. comm.). The removal of impervious surface in the recharge area of a fen, or the cessation of excessive withdrawal from local wells may also contribute to a fens hydrologic recovery. A stream or creek bordering a fen that has experienced down- cutting may also work to artificially lower water levels in the wetland. This can be corrected by placing sediment traps in the stream that would work to raise the streambed and cease the excess drainage. Removal and control of invasive or problem herbaceous species can be accomplished by hand pulling, deflowering, repeated cutting of stems, flooding, herbicide application, and prescribed burning (McGowan-Stinski 2004). McGowan-Stinski discourages hand removal in all but small infestations as it is labor intensive and causes excessive trampling. Additionally, many species can resprout from root fragments which 19

are rarely removed in their entirety with this method. Deflowering is the removal of the inflorescence before the plant has the chance to set seed and may help reduce the rate of spread of a species. Repeated cutting of stems may reduce the stores of energy that plants have for regrowth. This method is also very labor intensive and causes trampling of the site (McGowan-Stinski 2004). Flooding is possible in only specific situations and may help remove species intolerant to its effects. Herbicide application is often the most efficient and reliable means of invasive eradication though much care should be taken to not harm non target native species. Caution should also be taken to not introduce herbicide into the surface water of the fen. Prescribed fire effects on vegetation will be discussed in detail in an upcoming section. Removal of woody vegetation can be accomplished by cutting, cutting and treating with herbicide, girdling, or girdling with herbicide. Prescribed fire may be used to control established woody species and to prevent further establishment; again, this will be discussed in the review of prescribed fire effects on vegetation. Cutting woody vegetation with no application of herbicide has been shown to reduce woody cover in the first season after the treatment, but mortality was no different than in the control treatment. Cutting alone did however promote native forbs and discourage alien forbs (Clark and Wilson 2001). In a study on Rhamnus frangula, both girdling and cutting with no application of herbicide were not effective and resprouting occurred in 100% of the shrubs (Reinartz 1997). The author also commented that girdling is more labor intensive than simply cutting and treating the stumps with herbicide. The same study found that winter treatment of R. frangula by cutting and treating with 25% glyphosphate mixed with water within 5 minutes of the cut was much more effective (98% kill rate). Cutting stumps lower to the ground (within 5-15cm of the surface) was more effective than stumps cut higher (30-60cm). Cutting and treating is said to be effective in all seasons except in spring when sap is flowing (McGowan-Stinski 2004). However, Brock (2004) tested this theory with two types of herbicides (20% glyphosphate and 15% triclopyr in oil based dilutent) on Lonicera spp. and found that time of application was inconsequential. Shrubs treated in the spring did sprout back, but the sprouts died soon after. Both herbicide types were found to be equally effective, though he suggests glyphosphate as it is less expensive. Winter shrub removal may be best for wetlands as frozen soil will be less impacted by 20

trampling, access is easier, and there will be less damage to native vegetation from herbicide dripage or overspray (Reinartz 1997). From the literature it seems that cutting and treating with herbicide is much more effective than cutting or girdling woody species. In situations where herbicide use is prohibited, cutting should still be used as native vegetation responds positively. However, without herbicide these shrubs will likely resprout and reclaim the area in a few years. Prescribed burning is often used in fens to mimic the effects of fires that were historically influential in the maintenance of this wetland type in the landscape (Spieles et al. 1999, Crum 1988, Cattenhusen 1950) but have been suppressed since European- settlement. Few studies have reported the effects of fire on vegetation in fens or similar wetlands (Bowles et al. 1996, Clark and Wilson 2001). Kost and De Steven (2000) stated that prescribed fire can alter biomass production, flowering, and community composition in wetlands depending on frequency, intensity, and season of the burn. Mainly prescribed fire is used in these wetlands to control the invasion of woody species into the fen (Pendergrass et al. 1998, Spieles et al. 1999) and to help in the maintenance of diversity of plant species. Fires remove surface vegetation and litter, exposing soil surface to sunlight and increased daytime surface temperatures (Warners 1997) and decreased temperatures at night compared to areas with litter (Kost and De Steven 2000). These fluctuations may allow seeds in the seed bank to germinate and become established. Litter removal also is reported to promote earlier growth in the spring (Kost and De Steven 2000) and increases in biomass (Warners 1997). Warners also suggests that spring burns may be less effective at removing litter in sedge meadows as water levels are generally higher this time of year. The effects of prescribed fire will vary with its frequency of application. Single or infrequent burns in sedge meadows resulted in a change of species composition (Warners 1997). A study in a sedge meadow in Michigan’s Upper Peninsula saw richness increase after one burn but decreased after two consecutive burns. Seedlings were present in greater numbers in burned plots when compared to unburned plots likely due to removal of litter by fire (B. Ruhfel unpublished data). A single burn has also been reported to cause the return of species not seen in the study area for twenty years (Middleton 2002). Invasive species are also affected by fire and have been observed to increase after a single burn (Middleton 2002, Warners 1997). In contrast to infrequent 21

fires, annual fires may deplete the seed bank of short-lived species. In addition, certain plants may require more than one year without fire to produce seeds, and seeds dropped the previous year may not be in the soil and may be consumed by the fire (Kost and De Steven 2000). In a prairie fen studied by Bowles et al. (1996), yearly dormant season burns combined with cutting of shrubs led to graminoid dominance, a loss of forb diversity, loss of alien species, a gain of fen species, and no change in woody species. Fens seem to respond to fire within the first year or two and then the effects are reduced as time passes (Kost and De Steven 2000). In their study, Kost and De Steven observed greater live biomass in the first year after a burn but biomass declined in subsequent years. Also litter was removed but returned to previous levels in one or two years. Any increased cover or frequency of species lasted only one or two years as well. Differences were not found between an unburned fen and a fen burned seven years prior, suggesting that periodic fires with a recovery period may be the best strategy for the maintenance of species diversity (Kost and De Steven 2000). Long-term management with fire over a twenty year period increased richness in prairie plots and decreased richness in unburned plots (Bowles et al. 2003). In the same study richness of exotics increased in unburned plots and decreased in burned plots. Invasion of woody plants into fen habitat is one of the main reasons for initiating management in these wetlands. Bowles et al. (1996) advise that growing season burns are more effective at controlling shrubs than dormant season burns. Spring burns in a sedge meadow reduced vigor in willows with more frequent burning leading to further reductions in vigor and greater mortality, though many shrubs still survived the treatment and cover was minimally affected. Burns in this study may have had a reduced intensity after the first burn because of a reduction in fuel (Quinlan et al. 2003). This reduction in intensity may lower the effect of a burn on shrubs. Cattenhusen (1950) also observed shrubs responding to light burns with resprouting after being top-killed; more frequent fires reduced shrubs and allowed graminoids to increase in cover. Fall burning in a wet prairie was shown to top-kill shrubs but did not reduce their capacity to regenerate. In fact woody plant biomass increased the following year (Pendergrass et al. 1998). These authors suggest that burning alone will not eliminate woody species, but may reduce their height, density, and establishment and should stop their expansion. A study of fall burns in an Oregon wetland prairie reduced cover and survival the first season after the burn, 22

but the shrubs quickly resprouted regaining their original cover (Clark and Wilson 2001). Winter burns also do not seem to be effective means of control in sedge meadows (Middleton 2002) or prairie fens (Bowles et al. 1996). Burns at any time of year seem to set back woody shrubs briefly but many resprouts quickly regain cover and the ability to reproduce. Frequent burning will help to set back shrubs and reduce their vigor but will likely be unable to eliminate them from the site. Frequent burning to reduce shrubs may also have negative effects on the diversity of herbaceous vegetation, particularly forbs, by reducing or eliminating them from the seed bank (Kost and De Steven 2000). Annual fires in heavily infested areas may not be possible as shrub presence inhibits fuel build up and available fuel may be spent after one year of burning. Native herbaceous species respond to fire and likely have species specific reactions. This should be carefully considered when using prescribed fire to conserve rare species. However, general trends have been observed in forbs and graminoids and their reactions to prescribed fire in fens. It seems that forbs rely on the disturbance of fire to create sites for establishment and germination (Kost and De Steven 2000). Warners (1997) has observed increased forb seedling densities after burning. Observations of vegetative response after fire in sedge meadows also reveal an increase in forb cover and seedling density (B. Ruhfel, unpublished data). Warners (1997) specifically notes that tall forbs including asters, goldenrods, and Eupatorium spp. had a greater response than graminoid seedlings. Burning has been shown to promote native forb cover and the reduction in cover of non-native forbs (Clark and Wilson 2001). Frequency of burning is important in the reaction of forbs; annual burning will likely decrease forb density (Kost and De Steven 2000) and diversity (Bowles et al. 1996), while periodic fires are likely to increase their recruitment (Warners 1997) and richness (B. Ruhfel unpublished data). Graminoids increase in dominance with both annual fires (Bowles et al. 1996), and long periods without fire (Kost and De Steven 2000). Single or infrequent burns may not alter their dominance because graminoids are long-lived perennials that spread through vegetative reproduction (Warners 1997). Bowles et al. (1996) suggest that graminoid root growth is stimulated by fire and expand into areas cleared by fire more aggressively than forbs contributing to their exclusion. Spring burns help to set back growth of dominant sedges (Warners 1997) and aid in the recruitment of less dominant species (Kost and De Steven 2000) including both forbs and graminoids. 23

Sphagnum mosses, an important component in some fens, have been observed to reestablish on superficially burned areas where the water table is close to the surface (Catenhusen 1950). Fen restoration projects often rely on native vegetation from the seed bank or nearby sources to revegetate a degraded area. However, there is little known about the specifics of vegetation reestablishment in wetland restorations (Budelsky and Galatowitsch 1999). It is thought most species on a recently restored site originate from species in the surrounding area that have fast vegetative growth or are present in the seed bank (van Diggelen and Mars 2003). Relying on the seed bank is possible only when the soil has been undisturbed by farming or other activity, and the time since disturbance has been short. A degraded state of longer than ten years may leave only species with seeds that are persistent in the seed bank and reestablishment may be poor if degradation persists for an extended period (van Diggelen and Mars 2003). Jensen (2004) also states that restoration will be more successful if conducted soon after the disturbance. After thirty years of drainage in a wetland, species found in the seed bank were only a fraction of the plants commonly found in the original communities (Wetzel et al. 2001). Jensen (2004) found that in Germany many fen species have seeds that persist in the short-term, guarding species from periods of low seed production or seedling survival. Additionally, Jensen found that many species persist long-term in the seed bank and will therefore be available to revegetate an area if conditions are right after restoration. Restored fens are likely to be species poor when compared to intact fen habitat. Galatoswitch and van der Valk (1996) report that after three years of reflooding a wetland, the vegetation of the restored wetland was not similar to a natural wetland and had fewer overall species. Even with sufficient abiotic conditions, dispersal of propagules from nearby remnant fen species into restored habitat may not be sufficient to revegetate an area if the remnant populations are small or far from the restored site. Both Donath et al. (2003) and Cobbaert et al. (2004) found that dispersal was a limiting factor in establishment. Donath et al. (2003) observed that establishment from remnant populations did occur, but was over short distances in a ten year period. Of the three species studied, the median distance of dispersal was only 6 meters. Species with poor dispersal capabilities may need to be planted or their seed applied if they are not present in the seed bank (Galatoswitch and van der Valk 1996). 24

When native vegetation does not appear from the seed bank or establish from nearby remnant populations or when threats from invasives are high, planting the site with seeds or more developed plant material may be a necessity. Plant material can be ordered from nurseries or grown from seed and then planted. Another option suggested by Cobbaert et al. (2004) that has shown promising results is the transfer of soil from an intact fen into the degraded fen. This would bring species present in the seed bank, as well as mycorrhizae and insects to the degraded site. A drawback of this technique is the disturbance of the intact fen, and its costs may outweigh the benefits. Compared to acquiring and planting mature plants or seedlings, direct application of seed on site is a good option because of cost savings. As with information on establishment, literature on germination of seeds in restoration projects is lacking for wetland plants (Budelsky and Galatowitsch 1999). Local populations of fen and sedge meadow species serve as a good source of seed. Seed can be collected directly or hay from fens or meadows cut and simply spread in a thin layer on the restoration site. A large proportion of species (70%) were found to germinate and establish with this method in a degraded fen (Patzelt et al. 2001). Many seed collectors store seed in a cool dry environment that may not be suitable for fen species, especially Carex spp., common sedges in this wetland type. Budelsky and Galatoswitsch (1999) suggest that storage condition is very important in maintaining Carex seed viability, and recommend wet and cold storage (4°C and saturated). Among the species tested were C. stricta, C. lacustris, and C. lasiocarpa all of which are common in Midwestern fens.

Conclusion

Fens are a rare wetland type in the Midwest and support many rare species of both flora and fauna. Their occurrence in the landscape relies on specific factors including climate, physiography, geology, and hydrology all of which affect the water chemistry, vegetation, and soil development of a fen. The interrelation of these factors may cause fens to be particularly vulnerable to anthropogenic disturbances. Fens may be negatively affected by shifts in hydrology and water chemistry, suppression of fire, and introduction of invasive species. Management of fens is becoming more common, and many strategies exist to reclaim fens that have been degraded. These include restoration of 25 hydrology, removal of herbaceous and woody invasive species through herbicide application and prescribed fire, and the planting of a site to regain species composition. However, more research into the specific effects of management techniques on the flora and fauna of fens is needed. Discussion of successes and failures amongst land managers responsible for these incredibly diverse wetlands will also facilitate the development of better management techniques.

26

Chapter 2: Site Analysis and Observations

Introduction

Understanding current and historic conditions of a site is important when constructing a management or restoration plan. In particular, when considering management of fens, three main areas should be investigated: 1) current flora and fauna composition, 2) hydrology and evidence of its alteration, and 3) evidence of invasion by woody species. The rarity of this wetland type alone is enough to justify management, though presence of rare species may add further incentive. If present, rare species’ needs for reproduction, growth, and continued success in the wetland should be a factor driving management decisions. Presence of invasive species, especially those known to be problematic in fens, should play heavily into management considerations as they may negatively affect rare species present or the establishment of a restored area with native fen species. Any past alteration of hydrology, such as drainage tiles or ditches, should be investigated and addressed if restoration is to be successful. Additionally, lack of fire can alter the structure of vegetation in fens by allowing increased establishment of woody vegetation (Spieles et al. 1999). The Matthaei fens have not burned in the last 55 years, though time since the last burn in either site is likely greater. Periodic fires may have occurred in Radrick Forest after logging in the 1820s and 1830s. These fires likely continued through the 1930’s (Barnes unpublished data) and some probably extended into Radrick Fen. No information was found concerning the last time fire may have occurred near or in Kirk’s Fen. The following investigations were conducted at Kirk’s Fen and Radrick Fen at Matthaei Botanical Gardens to determine site conditions related to species present, hydrologic alterations, and woody species invasion: 1) vegetation survey and Floristic Quality Assessment (FQA), 2) soil and water table measurements, and 3) aerial photograph analysis of shrub encroachment over the past 53 years. FQA is a tool designed to assist land managers in assessing the natural significance of any area in Michigan. While not suggested as a single method of assessment, it is a good measurement when combined with other methods of site evaluation (Herman et al. 2001). Additionally, general observations of site conditions were made considering vegetation 27

patterns, soils, and hydrology. Information gained through these investigations will guide management or restoration recommendations specific to each site.

Methods

Kirk’s Fen and Radrick Fen are located on the University of Michigan’s Matthaei Botanical Gardens property in Washtenaw County (Fig. 2). Kirk’s Fen is located in Superior Township in the southwest quarter of section 18 (T. 2 S., R. 7 E.). Radrick Fen is located in Ann Arbor Township, in the southeast quarter of section 24 (T. 2 S., R. 6 E.). Both sites are primarily used for research and educational purposes, and are not visited in any great numbers by the general public.

Vegetation Survey and Floristic Quality Assessment

A species list of vegetation for each site was compiled over a series of visits in August and September of 2004 and April and May of 2005. A previous FQA of Radrick Fen had been conducted by Reznicek et al. (1999) using a species list gathered in late 1998 and early 1999 and was used as a baseline inventory. No previous species list or FQA has been conducted in Kirk’s Fen. Fen boundaries were determined by 2002 aerial photographs and all plants found within the graminoid dominated portion of the fens, as well as those in the semi-open shrub border of the fens, were recorded. A Floristic Quality Assessment (FQA) was then performed for each fen as described in Herman et al. (2001). FQA consists of determining species richness, a mean coefficient of conservatism (C¯), a Floristic Quality Index ranking (FQI), a wetness index (W¯ ), and a summary of the physiognomic classes. The coefficient of conservatism for a species is ranked on a scale of zero to ten and represents “an estimated probability that a plant is likely to occur in a landscape relatively unaltered from what is believed to be pre- European settlement condition.” A zero rank is given to plants that are found almost anywhere; a rank of ten denotes plants that are restricted to presettlement condition, i.e. high quality areas. To calculate the FQI, a mean coefficient of conservatism (C¯) is first calculated by summing the coefficients of conservatism from the plant list and dividing by the total number of plant taxa (n), giving C¯ = ∑C/n. This mean (C¯) is then multiplied 28

by the square root of the total number of plants at the site (n) giving the FQI value (FQI = C¯√n). To calculate the wetness index, the mean coefficient of wetness (W¯ ) is calculated by dividing the sum of all coefficients of wetness by the number of taxa found at the site (n), giving W¯ = ∑W/n. This mean value is considered the wetness index. The coefficient of wetness is similar to the coefficient of conservatism, but is “the estimated probability for which a species occurs in wetlands” and ranges from -5 (almost always in wetlands) to 5 (almost never in wetlands). Nomenclature follows that used in the Michigan Plants Database included in Herman et al. (2001).

Soil and water table measurements

Soils at each site were examined in April 2005 using a soil borer to determine the nature of the soil to 1 m in depth. No attempt was made to measure specific soil profiles, only general trends. Soil was classified as sapric-hemic, hemic-fibric, mineral, or mixed. Sapric-hemic peat was defined as soil with less than 50% identifiable plant matter. Hemic-fibric peat was defined as greater than 50% identifiable plant matter. Mineral soil was composed mainly of sand, silt, or clay. The mixed designation was applied when soil characteristics were a combination of both mineral soil and peat. In this category the peat portion was described as before, either sapric-hemic or hemic-fibric. To gauge depth of peat a 1.83 m piece of steel rebar was pushed by hand into the soil as deep as possible. The deepest measurement possible was 1.7 m as the remainder was needed to pull the rebar out of the soil. If a soil layer stopped the rebar from being fully inserted, then the depth of that layer to the nearest 0.1 m was recorded. Water table height above or below the surface of the soil was measured to the nearest centimeter. The soil borer hole was used to measure depth of water table beneath the surface. If the water table was at the surface it was recorded as “surface.” Three transects placed with the aid of aerial photographs were used to guide sampling at each site, one parallel to the slope and two perpendicular. Transects were placed to begin and end outside original fen boundaries as determined by historical aerial photographs (Figs. 3 and 4). At each site sampling units on the transect running parallel to the slope were spaced every 30 m. On transects perpendicular to the slope sampling units were spaced at 15 m intervals. At Radrick Fen there is a small ridge that drops 29

down into the fen along the eastern and southern edge of the site; transects were started at the base of that ridge.

Aerial photograph analysis of shrub encroachment

A series of aerial photographs between 1949 and 2002 was used to obtain the graminoid dominated area within each fen for each year available. Aerial photos were georeferenced and shrub lines onscreen digitized using Arc Map 9.0 (ESRI 2004). Aerial photographs were obtained from the University of Michigan’s Map Library from the years 1949, 1955, 1963, 1969, 1980, 1985, 1990, 1995, 2000, and 2002. Aerial photos for each year were rectified with 2003 State of Michigan geographic framework road data (MGF 2004). A first order polynomial transformation with 5 to 6 ground control points was used to adjust the photos to the coordinate space of the roads. The ground control points were established road intersections. Onscreen digitizing of the shrub line was visually estimated from each photo and the area (measured in ha) contained within the shrub line was assumed to be graminoid dominated. After onscreen digitizing, the shrub line of Radrick Fen was field checked during October 2004 using a Trimble GeoExplorer 3 handheld GPS unit with antenna. Digitized estimation of the shrub line boundary for the 2002 aerial photo was then visually compared to 2004 field measurements to check for accuracy in judgment. Shrub line boundaries were similar in each measurement and this method was determined sufficient for observing generalized trends in the change of fen area through time. Area was then plotted against year to create a visual representation of change over time. Original area (1949) was compared to current area (2002) and expressed as percent change. Mean loss of ha per year was also calculated.

General site observations

General observations of site conditions were made at each location during several visits in the summer of 2004 and the early spring of 2005. These included comments relevant to the vegetation patterns, soil characteristics, and hydrology that were not specifically measured by the previously mentioned methods.

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Results

Vegetation Survey and Floristic Quality Assessment

Kirk’s Fen species richness was 113 with 95 native species. Mean coefficient of conservatism was 4.7 (4.0 with adventives). Adventive species are not native to Michigan and have become established since European settlement. Native FQI ranking was 46.2 (42.3 with adventives). Native mean W was -1.8 (-1.3 with adventives) placing the wetness index for the site in the facultative wetland minus (FACW-) category. Native perennial forbs were the dominant physiognomic class constituting 41.6 % of the species. Native tree and shrub classes each comprised 9.7 %, followed by native perennial sedges at 7.1 %. Two State threatened species were found in Kirk’s Fen: Cypripedium candidum and Valeriana ciliata. Eighteen adventive species were present at this site including Rhamnus frangula, Rhamnus cathartica, and Lythrum salicaria. Phalaris arundinacea was also present. See Table 2 for detailed FQA data on Kirk’s Fen including physiognomic class percentages and FQI ratings. See Table 3 for a species list of Kirk’s Fen. Radrick Fen species richness was 137 with 133 native species. Mean coefficient of conservatism was 5.3 (5.2 with adventives). Native FQI ranking was 61.4 (60.5 with adventives). Native mean W was -2.9 (-2.8 with adventives) placing the wetness index for the site in the facultative wetland (FACW) category. Native perennial forbs were the dominant physiognomic class constituting 50.4 % of the species. Native shrubs constituted 13.9 % of the species, followed by native perennial sedges at 11.7 %. State threatened species found in Radrick Fen included Sanguisorba canadensis and Valeriana ciliata. Four adventive species were found at Radrick Fen: Rhamnus frangula, Lythrum salicaria, Malus pumila, and Poa pratensis. See table 4 for detailed FQA data on Radrick Fen including physiognomic class percentages and FQI ratings. See Table 5 for a species list of Radrick Fen. Table 13 lists species present in inventory by Reznicek et al. (1999) but not found in inventories for this report.

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Soil and water table observations

Soils in Kirk’s Fen were a mixture of mineral soil and sapric to fibric peat to the depth of 1 m. The rebar was able to be inserted to a depth greater than 1.7 m except near the outermost sampling units of the parallel transect and the northern units of the western perpendicular transect. Water table levels ranged from being present at the surface to 48 cm below. Only one measurement was deeper than 28 cm below the surface. This 48 cm measurement was located at the southernmost sampling unit on the western transect. Soil descriptions and measurements for rebar depth and water table levels in Kirk’s Fen are given in Tables 6a-6c. Soils in Radrick Fen sampling units were generally hemic to fibric peat to the depth of one meter. Two sampling units, one on the northern edge and one on the eastern edge, had sapric muck overlaying hemic or fibric peat. In the central portion of the fen depth of peat (determined by rebar insertion) ranged from 1.2 m to greater than 1.7 m; the water table was most often at the surface, but ranged from 5 cm above to 8 cm below. The most western sampling points on each of the perpendicular transects were located in the flood plain of Fleming Creek. The soil here was saturated mineral soil (silt loam) and the rebar was able to be pushed to a depth of 0.9 m and 1.1 m before being stopped by a dense soil layer. At the westernmost sampling unit on the southern transect a water table measurement of 46 cm below the surface was made. Soil descriptions and measurements for rebar depth and water table levels in Radrick Fen are given in Tables 7a-7c.

Aerial photograph analysis of shrub encroachment

Graminoid dominated fen area for each year is listed in Table 8 and represented graphically in Fig. 5. Open areas in Kirk’s Fen have decreased from 0.73 ha in 1949 (Fig. 6) to 0.09 ha in 2002 (Fig. 7), a reduction of 88%; mean loss of ha per year was 0.15. Open areas in Radrick Fen have decreased from 0.81 ha in 1949 (Fig. 8) to 0.56 ha in 2002 (Fig. 9), a reduction of 31%. Mean loss of ha per year in Radrick Fen was 0.005.

32

General site observations

Vegetation in Kirk’s Fen is separated into two sections with gradation occurring between the two. In the central open portions of the fen not dominated by Rhamnus spp., native fen vegetation is dominant. Here vegetation is predominantly forbs and graminoids with occasional shrubs; vegetation height is less than 1 m and full sun is available throughout the year. In these areas enough fuel is present for prescribed burns to occur. Some invasive species are also present in the open portions and include small individuals of Lythrum salicaria and Rhamnus frangula. In the surrounding, shrub dominated area Rhamnus frangula and Rhamnus cathartica reach heights of 4 m or more and block sunlight from reaching the ground. Groundcover is nearly absent and species present are more typical of uplands, disturbed ground, and low light conditions; Phalaris arundinacea is present in small patches. Prescribed fire would not move through this area due to lack of fuel. Where these two sections grade into each other, stunted individuals of species found in the open portions of the fen, such as Potentilla fruticosa, Allium cernuum, and Carex spp. occur. Threatened species found at this site, Cypripedium candidum and Valeriana ciliata, are found only in the open portions of the fen. Many individuals of V. ciliata are present, but only one clump of C. candidum was present in spring of 2005. Throughout this site many understory and large overstory individuals of Larix laricina are present. Roots of trees and shrubs in the buckthorn dominated area are exposed. Gray calcium rich soils are visible, with many small shells present in the mucky loam. Small rivulets of running water are present throughout Kirk’s Fen and springs can be seen discharging from the bank adjacent the fen into Fleming Creek. Kirk’s Brook to the south of the fen appears to be down-cut. Radrick Fen vegetation is typical of prairie fens with a central sedge meadow zone surrounded by a zone dominated by trees and shrubs (Spieles et al. 1999). Vegetation in the sedge meadow zone is dominated by Carex stricta, Schoenoplectus acutus, Betula pumila, Potentilla fruticosa, Valeriana uliginosa, and Sanguisorba canadensis. Mounds of Sphagnum spp. occur throughout this zone and are especially prevalent at the southern end of Radrick Fen. Threatened species at this site, Sanguisorba canadensis and Valeriana ciliata, are present in large numbers in the central 33 portion of the fen. Vegetation height is predominantly less than 1 m. Within the sedge meadow zone there are areas of calcareous groundwater seepage. A large area of this type lies near the northern end of the fen and many smaller areas occur throughout. Soils in the seepage zones are typically gray in color and many shells are visible at the surface. In the southwest section of Radrick Fen there is a sizable population of Phragmites australis that seems to be spreading into the central portion of the fen. A small number of Lythrum salicaria individuals are also present in the fen. In the surrounding tree and shrub zone Carpinus caroliniana, Rhamnus frangula, and Physocarpus opulifolius are dominant. Unlike Kirk’s Fen, there is enough fuel present in both vegetation zones to carry prescribed fire. Rivulets of running water are present in Radrick Fen running perpendicular to the slope, towards Fleming Creek and springs discharging into the creek from the direction of the fen are visible. Sistrurus catenatus catenatus, a state snake species of special concern and currently being considered for federal listing, was observed in Kirks fen on two occasions and once in an upland area very near to the fen. One observation of this snake was made in Radrick Fen. In the spring of 2005 a drain tile was found underneath a fallen tree on the edge of Fleming Creek, just outside the area of this study. This tile was located at the end of what looked like a natural stream draining the area to the north of Radrick Fen into Fleming creek. Little is known about this particular drain tile, and no others in the area have been observed.

Discussion

Vegetation Survey and Floristic Quality Assessment

Both Kirk’s Fen and Radrick Fen had high FQI rankings, indicating that they are important to preserve as representative samples of our native vegetation, with Radrick being an exceptional site. Most undeveloped land in Michigan scores under 20 on the FQI and has little natural significance. Sites scoring above 35 are considered floristically important from a state wide perspective, and sites above 50 are considered extremely rare examples of Michigan’s native biodiversity (Herman et al. 2001). Kirk’s Fen scored an 34

FQI of 46.2 and Radrick Fen’s score was 61.4. Of six fens in Ann Arbor that have been evaluated using the FQA, these sites score the two highest FQI rankings, and in fact are among the highest ranked of all sites of any community type measured in Ann Arbor (NAP 2003). Herman et al. (2001) and Rooney and Rogers (2002) suggest that when comparing sites of similar communities mean C should be used instead of FQI rankings. Rooney and Rogers go further and state that mean C is a more useful measurement as it is less sensitive to sample size, preserves more information, and provides more intuitive results. Using data from the same NAP study, mean Cs measured during the FQAs for this report were also the highest of all fens listed. A further indication of these fens value is the presence of two threatened plant species at each site. Other fens in Ann Arbor had no special concern, threatened, or endangered species present. FQI scores, mean C results, as well as the presence of three threatened plant species and one snake species of special concern, highlight the fact that these areas are unique in Ann Arbor and all of Michigan and should be protected from threats to their presence in the landscape. When compared to Radrick Fen, Kirk’s Fen had lower species richness, more non-native species, a lower mean C, a lower FQI ranking, and scored slightly drier on the wetness scale. This is not surprising considering the greater amount of invasion by Rhamnus frangula at this site and the probable loss of species caused by this shrubs ability to shade out native fen species (Eggers and Reed 1997) and change species composition, dominance, and cover under its canopy (Possessky and Williams 2000, Frappier et al. 2003a). Plants that require full sun cannot persist in the low light conditions created by dense stands of R. frangula. Drier conditions at Kirk’s Fen may be the result of the many shrubs lowering the water table or could be an indication of this site receiving less groundwater flow than Radrick. Further investigations of the hydrology of the area would be needed to explain this. If the shrubs are removed, water table monitoring wells would reveal if shrub presence was the cause of a lowered water table. Drier conditions may allow more invasives to colonize Kirk’s Fen than the wetter Radrick Fen. Many of the adventives in Kirk’s Fen are characteristic of drier upland sites such as Rhamnus cathartica, Lonicera spp., Rosa multiflora, and Hesperis matronalis (Herman et al. 2001). Lythrum salicaria and Rhamnus frangula were present at both sites and are considered to be threats to prairie fens (Spieles et al. 1999)

35

Distributions among the physiognomic classes at each site were similar to each other and to Michigan’s plants as a whole with perennial forbs being the most represented physiognomic class. Physiognomic class percentages are included here to provide a baseline for each site as categories may shift over time, especially with management (Herman et al. 2001). Complete FQA results are listed in Tables 2 and 4.

Soil and water table observations

Water table levels at both sites are typical of Midwestern fens (Amon et al. 2002) and no evidence of drainage tiles was found in the sampling areas. Presence of tiles would cause large drops in the water table level in central areas of the fen (pers. comm. D. Tilton) and these drops in levels were not observed. Each site had one sampling unit with a water table level near 50 cm below the surface. However, these measurements were near the streamside edge of the fens and are likely a result of the water table dropping to the level of the stream surface and should be considered natural. It is probable that the hydrology of Kirk’s Fen has been affected by the impervious surfaces of roads and buildings present nearby, such as the recent housing development across Dixboro Rd., nearby Kirk’s Fen. These impervious surfaces may be blocking portions of the recharge area that supplies groundwater to Kirk’s Fen and Spieles et al. (1999) report that many prairie fens with disrupted recharge areas transition to shrubb-. This transition is occurring in Kirk’s Fen. Impervious surfaces may also contribute to higher levels of surface water input than historically present. Greater surface water input contributes to greater amounts of sediment and nutrients reaching the fen (Spieles et al. 1999). Additionally, changes in the ratio of surface water to groundwater input may change pH (Glaser 1990). Changes in pH may then affect nutrient availability, plant establishment, and reproduction. Small pH changes have in fact been linked to vegetation response in peatlands (McNamara et al. 1992). Further investigations into the hydrology of the area surrounding Kirk’s Fen would be needed to determine if the recharge zone has been affected or local wells are drawing the water table down. Radrick Fen’s hydrology is likely in better condition because of its isolated position in the landscape, although it too may have been influenced by past human activity. Gravel mining occurred in the area between Radrick Forest and Radrick Fen 36

(Klatt 1999) and may have affected the hydrology in some way, as quarrying is known to affect groundwater flow (Bedford and Goldwin 2003). The intact forest upslope from Radrick Fen is beneficial to the long term stability of the wetland. This forest allows precipitation to enter the recharge area maintaining groundwater flow to the fen and limiting surface water input (Spieles et al. 1999). Water table and soil observations at Kirk’s Fen suggest that this site has less groundwater supply throughout the year than Radrick Fen. Levels at Kirk’s Fen were typically 10 to 20 cm below the surface compared to most levels in Radrick Fen being at the surface or within 10 cm. Lower water table levels will contribute to higher decomposition rates (Amon et al. 2002), and in fact, soils at Kirk’s Fen were more decomposed than those at Radrick Fen. Soil in Kirk’s Fen was a mixture of mineral soil and peat, with the peat portion more often sapric in nature than fibric. Sapric peat is considered typical of prairie fens (Spieles et al. 1999) and may be a sign of limited water availability at a site allowing for higher levels of decomposition (Amon et al. 2002). Samples that were recorded as having a hemic-fibric peat portion were more decomposed than hemic-fibric samples at Radrick Fen. Mineral components of the soil at Kirk’s Fen are likely deposited by upslope erosion and flood events from Fleming Creek (Amon et al. 2002). Amon et al. also state that fens with a mineral soil component may have complex soil profiles with alternating layers of peat of varied decomposition and mineral soil. This was indeed the case at Kirk’s Fen. Soils at Radrick Fen were nearly all classified as hemic-fibric, and consisted of mostly fibric peat. Those classified as sapric- hemic at the surface were on the edges of the fen in areas with standing water. Fibric peat is likely maintained at Radrick Fen due to sustained discharge groundwater throughout the year. Lower overall water levels at Kirk’s Fen may also provide more suitable germination and establishment conditions for invasive herbaceous species and woody species both native and invasive. It should be noted that water levels were taken early in the season before most of the shrubs had flushed. The shrubs at Kirk’s Fen may draw water levels down further throughout the growing season through transpiration. Water table monitoring wells installed would help detect if this were the case. Depth of peat soil seems greater at Kirk’s Fen as only sampling stations near the edges encountered a solid layer beneath the peat within 1.7 m of the surface. In contrast Radrick Fen had sampling units in the center of the site that encountered an impenetrable 37 barrier within 1.7 m of the surface. It is possible that Radrick Fen is maintained with lesser amounts of groundwater discharge than Kirk’s Fen because of this shallow impermeable layer. Nutrient levels at Kirk’s Fen may be higher than at Radrick Fen because of lower water levels allowing greater peat decomposition. Undecomposed peat stores nitrogen, and this nitrogen is released during decomposition (Crum 1988). Sediment and nutrient levels would also be increased by flood events from Fleming Creek (Beford and Godwin 2003). Rhamnus spp. may also contribute to higher nitrogen levels in the soil at Kirk’s Fen through rapid decomposition of its leaf liter. This enrichment of nutrients may help to maintain its dominance (Heneghan et al. 2004). High levels of nutrients have been shown to lead to declines in species richness and monotypic stands of vegetation in prairie wetlands (Green and Galatowitsch 2002) and fens in particular (Panno et al. 1999, Drexler and Bedford 2002). This greater nutrient availability may lead to Kirk’s Fen having a different plant composition than Radrick Fen with fewer species present after restoration.

Aerial photograph analysis of shrub encroachment

Graminoid dominated area in each fen has decreased through time due to shrub encroachment, both native and invasive. Possible explanations for this reduction are the suppression of fire and the alteration of hydrology. Fire is known to exclude shrubs in fen habitats (Curtis 1971, Jacobson et al. 1991). Also, alterations in hydrology resulting in a lowered water table would allow upland species to colonize fen habitat previously unavailable. Additionally, as shrubs colonize the exterior of the graminoid dominated openings, the water table is further drawn down (Jacobson et al. 1991), thus allowing increased establishment of woody species toward the interior of the fen. A reduction in the amount of open area in each fen occurred from 1949 to 1980 (Table 8). Loss of open area in Radrick then leveled off and remained at a constant size from 1980 to 2002, perhaps reaching a new equilibrium in response to unknown changes in the local landscape (Fig. 5). After 1980, reduction of open area in Kirk’s Fen continued at a similar rate until reaching 0.10 ha in 1995 and hovering near that value through 2002. The remaining open areas at Kirk’s Fen may be the wettest portions of the fen, somewhat 38

limiting shrub invasion. Variation between the 1949 and 1955 values of graminoid dominated area in Radrick are likely due to errors in shrub line interpretation rather than actual changes in shrub line position. Quality of aerial photographs varies widely and may affect the accuracy of the onscreen digitizing process. Radrick Fen has experienced a 31% reduction in graminoid dominated area since 1949 in comparison to an alarming 88% reduction in Kirk’s Fen. This may be due to the more protected nature of Radrick Fen’s placement in the landscape and the intact condition of Radrick forest upslope of the fen. This intact forest may allow uninterrupted recharge of the groundwater that feeds the fen (Spieles et al. 1999). Being more secluded from development than Kirk’s Fen may also have slowed the introduction and colonization of invasive woody species. Kirk’s Fen’s proximity to Dixboro Road and private land may account for easier and more frequent colonization of invasive woody species. Also, a reduction of the groundwater recharge area due to development upslope from Kirk’s Fen may have reduced the amount of groundwater feeding the fen causing drier conditions that would allow for greater shrub establishment. Further hydrological investigations would be needed to substantiate this claim. This difference in proximity to human development may also account for the three times greater mean loss of hectares per year in Kirk’s Fen compared to Radrick Fen.

General site observations

Rhamnus spp. invasion is extensive at Kirk’s Fen and is changing the composition of the vegetation and threatening the threatened species that occur there. If typical fen vegetation, including the threatened species, is to return to its former extent these shrubs must be removed and kept from returning to the site. Small patches of native fen vegetation in the center of the site should be protected at all cost and will supply a source of propagules for revegetation in the event that restoration measures are implemented. However these islands of remaining habitat will likely not be sufficient to revegetate the entire site; establishment from remnant populations has been observed to occur only over short distances in a similar community type (Donath et al. 2003). A few small individuals of Lythrum salicaria are present in the open areas and should be hand-pulled before the population becomes better established. Presence of fen vegetation lingering in 39

the Rhamnus understory is an indication that fen species may still be in the seedbank. Stunted individuals are likely to respond to shrub removal with increased vigor, further contributing to reestablishment of native vegetation. Due to the period of time Kirk’s Fen has been disturbed, the species still present in the seedbank are likely to only be a portion of the original species composition of the site and reestablishment may be poor (van Diggelen and Mars 2003). Lack of groundcover here also puts the site at risk for establishment of invasive or non-fen species after shrub removal. Phalaris arundinacea is present at this site and is known to be problematic in the restoration of sedge meadows. It is recommended this species be removed before restoration is begun as its invasion can prevent establishment of sedge meadow vegetation (Perry and Galatowitsch 2004). Possible seedbank deficiency and invasion by unwanted species indicate that seeding or planting Kirk’s Fen with native fen vegetation may greatly increase the success of restoration efforts at this fen. Establishing a cover of native species is effective in avoiding invasion by Phalaris arundinacea (Lindig-Cisneros and Zedler 2002) and is likely to deter other invaders as well. Radrick Fen is a possible source of seed for restoration efforts in Kirk’s Fen. Prescribed fire is used to control the presence of both woody and invasive species in fens (Spieles et al. 1999). Lack of ground cover in the shaded areas of Kirk’s Fen will inhibit the reintroduction of fire after shrub removal. A period of one to two years may be needed before fuel buildup is sufficient for prescribed burning. Seeds of Rhamnus spp. present in the seedbank will sprout after shrub removal. If ground cover is insufficient to carry prescribed fire, propane torches may be needed to treat the seedlings. Mortality of trees and shrubs left standing may occur once prescribed fire is used in this site as their roots are exposed. Exposed roots of trees and shrubs may be an indication of lowered water levels from shrub invasion. As shrubs bring down the water level, peat would be exposed to air contributing to decomposition. As decomposition continues roots once embedded in peat would be exposed. Shrubs in a peatland where fire occurred were protected only when rooted in peat hummocks, but fires that destroyed these hummocks also destroyed the shrubs and contributed to the development of a sedge dominated wetland (Crum 1988). Radrick Fen does not have near the level of Rhamnus spp. invasion that has occurred in Kirk’s Fen, though the areas surrounding Radrick Fen are heavily invaded. 40

Spread of Rhamnus frangula has been much slower here and has not altered vegetation as drastically. Radrick Fen may be less invaded because of its secluded location in the landscape and its higher water table level. Rhamnus cathartica is not present at all in the fen, likely because this site is much wetter than Kirk’s Fen. In shrub dominated areas ground cover is still present and dominated by native fen species. However, removal of these Rhamnus individuals should be conducted before the situation worsens. The spread of Phragmites australis into the fen is a cause of concern. A study of the invaded area in Radrick Fen revealed that species typical of high quality areas are less frequent in its presence (Gladwin 2003). It is unknown if this population of Phragmites australis is a native or invasive strain (pers. comm. T. Reznicek), however its control may be warranted as it is reducing the habitat suitable for threatened species at this site. Lythrum salicaria in Radrick Fen should be removed as soon as possible as it is also known to invade prairie fens (Spieles et al. 1999). Presence of Sistrurus catenatus catenatus, a state species of special concern and a federal candidate species, in these wetlands is further reason for protection and management of the fens. These snakes are often found in prairie fens and related wetland types and hibernate in these wetlands. Threats to open habitat structure of prairie fens, suppression of fire and alterations of hydrology, can then be seen as a threat to these creatures. Management of these wetlands is considered crucial for the conservation of these snakes (Lee and Legge 2000). Presence of gray calcium rich soils in both Radrick Fen and Kirk’s Fen indicate a supply of calcium carbonate from groundwater discharge. Rivulets of water on the surface and springs discharging into Fleming Creek are evidence that the hydrology of each site is still intact (pers. comm. D. Tilton). With intact hydrology, the removal of shrubs and the reintroduction of fire may be sufficient to maintain Radrick Fen and to restore Kirk’s Fen to it former size and species composition. Down-cutting of Kirk’s Brook may be draining Kirk’s Fen and contributing to its lower water table levels. Sediment traps could be used to raise the level of the streambed to ameliorate this problem. The drainage tile observed near the edge of Fleming Creek is probably not affecting the water levels in Radrick Fen though it may be altering the hydrology of the area to the north of Radrick Fen. Further investigations should be made in the area to reveal if any other drainage tiles are present and if their removal is warranted. 41

Management recommendations

Kirk’s Fen

A set of conditions has been proposed by van Diggelen and Mars (2003) that must be present for the successful restoration of plant communities. These include: 1) correct abiotic conditions within the tolerance of the target species, 2) presence of propagules of target species on site, 3) establishment requirements of target species met by site conditions, and 4) that following management must be appropriate and will likely include disturbance to create recruitment gaps. Even with these requirements met these authors suggest that the composition of a restored site may be different than the model system or in this case an idealized fen. The first three conditions are met at the Kirk’s Fen site. The fourth condition would be met by the re-introduction of fire after removal of the shrubs in the central portion of the fen. Management here, especially in the case of Kirk’s Fen, should be flexible in the event that an unexpected composition of plant species occurs after restoration efforts are implemented. If unexpected native or invasive vegetation does develop, this may indicate that conditions at the site are inappropriate for the target community. Monitoring may help to explain these patterns if they do occur (Kloetzli and Grootjans 2001). The high quality of Kirk’s Fen as registered by the 46.2 FQI ranking, the presence of two threatened species of plants, and one snake species of special concern as well as the rarity of prairie fens in general should make this site a priority for conservation. Before any restoration work begins at this site the area should be cleared of Phalaris arundinacea. This species is known to cause problems in fen restoration efforts (Perry and Galatowitsch 2004) and once established, reduces wetland diversity (Green and Galatowitsch 2002) by displacing native vegetation and reducing species richness (Lindig-Cisneros and Zedler 2002, Kercher et al. 2004). After this task is accomplished all invasive shrub species, especially Rhamnus frangula and Rhamnus cathartica, should be cleared from the site by the cut and herbicide treatment method. In fact all shrubs, both native and invasive should be cleared from the site to help in raising the water table level. This will also make the removal of shrubs from the area easier and reduce the 42

chance of missing small Rhamnus spp. individuals. Shrub removal should cause the water table levels to rise returning to pre-invasion water table levels. In addition to removing the shrubs, water table levels may rise if the streambed of Kirk’s Brook is raised. In-channel stream slowing and sediment trapping measures should be explored as a way to ameliorate the down-cutting that has occurred. Annual spring burns would then be used in the reclaimed areas for at least five consecutive years to exhaust invasive species in the seed bank and to control woody species establishment. If fuel buildup is insufficient to apply prescribed burns, then propane torches will be used to kill woody seedlings until prescribed burns can occur. One third of the intact portions of the fen would be burned in the spring once every five years to maintain diversity of herbaceous species at the site especially forbs. The threatened species here, Cypripedium candidum and Valeriana ciliata, will also benefit from management including prescribed fire and shrub removal (MNFI 2005). Burning should be conducted with care so Sistrurus catenatus catenatus individuals are not killed in the fire (See Appendix A). Because the site has a large areas with bare soil, success of restoration efforts will likely be improved if the area is planted or seeded with propagules from a local source, i.e. Radrick Fen. The faster native cover is attained, the less the threat of establishment of invasive species. Lythrum salicaria is present now only in small numbers. Hand-pulling should be adequate to control it and should be the preferred method as herbicide use should be avoided when possible. Monitoring of the reclaimed area for invasive or problematic species should be diligent in the first few years to prevent their establishment and spread. After fire has been reintroduced to Kirk’s Fen and the populations of invasive species are removed or at least under control, prescribed burning and work to remove invasive species should move into the areas adjacent to the wetland to create a healthy landscape continuum.

Radrick Fen

Radrick Fen is an extremely high quality prairie fen. This is evident in its FQI score of 61.4, making this site a rare example of Michigan’s native biodiversity (Herman et al. 2001). The presence of two threatened plant species and one snake species of special concern only adds to its value. Invasive species are present, though are in low 43

number and have not yet managed to severely alter the vegetation at this site especially when compared to conditions in Kirk’s Fen. A less aggressive management strategy is needed here and a minimal amount of work done now will cut down on the amount of work needed if management is left until sometime in the future. Rhamnus frangula is present in the shrub borders of the fen and should be removed by the cut and herbicide treatment method. Native shrubs can be left standing as the water table levels are not an issue here. Burning one third of Radrick Fen every five to seven years will help to maintain the diversity of herbaceous species at this site. Burning should extend as far into the shrub borders as fuel levels allow to control woody plant invasion into the central portions of the fen. Burning and shrub removal will also benefit the threatened species, Sanguisorba canadensis and Valeriana ciliata (MNFI 2005). As in Kirk’s Fen, burning should be conducted with care so Sistrurus catenatus catenatus individuals are not killed in prescribed fires (See Appendix A). Individuals of Lythrum salicaria are scattered throughout the site and are small enough to be controlled by hand pulling. The population of Phragmites australis should be controlled by herbicide application. If herbicide use is to be kept to a minimum, annual cutting in July when the plant’s resources are stored in above ground plant material may be effective in reducing the population (Marks et al. 2005). Radrick Fen may have once extended further to the north of its present condition. After fire has been reintroduced, and the populations of invasive species within the fen have been removed or are no longer a threat, work should move to expand the open areas of the fen to the north by removing Rhamnus spp. and reintroducing fire. Removal of invasive species in the uplands surrounding Radrick Fen should also be a priority after the core area of the fen is cleared of invasives.

The management suggestions for the Matthaei Botanical Gardens’ fens will be expanded and explained in the following chapter and presented as a comprehensive management and restoration plan.

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Chapter Three: Kirk’s Fen Restoration and Management Plan

Introduction

Kirk’s Fen at the University of Michigan’s Matthaei Botanical Gardens is a rare wetland type in need of management for its survival. Fens are a type of wetland whose vegetation, water chemistry, and soil development are determined by ground water flow (Bedford and Godwin 2003). Kirk’s Fen in particular, is a prairie fen as defined by the Michigan Natural Features Inventory (MNFI). This fen type occurs only in the glaciated Midwest, and differs from other calcareous fens by the presence of a tallgrass prairie flora and fauna component (Spieles et al. 1999). MNFI lists prairie fens as being globally restricted in their range making them vulnerable to extinction, and rare or uncommon in the state of Michigan (MNFI 2005). This fen had approximately 0.73 ha of open graminoid dominated area in 1949. Since that time, the invasion by shrubs, mainly Rhamnus frangula and Rhamnus cathartica, in this wetland has reduced the size of these open areas of the fen to 0.09 ha. This 88% reduction has severely altered the species composition at the site, replacing native fen species with species not usually found in this wetland type. Probable reasons for this drastic change in the vegetative structure of this fen are interrelated results of an altered fire regime, addition of invasive species, and changes in the hydrology of the area. The value of this fen to both the state of Michigan and the Matthaei Botanical Gardens is highlighted by the presence of two state threatened plant species and one snake species of special concern currently being considered for federal listing. Additionally, a Floristic Quality Assessment of the site registered a Floristic Quality Index ranking of 46.2. This score places Kirk’s Fen in a category of sites that are floristically important to the state of Michigan (Herman et al. 2001). Of six fens in Ann Arbor that have been evaluated using the FQA, this site scored the second highest FQI ranking, second only to Radrick Fen, and in fact is among the highest ranked of all sites of any community type measured in Ann Arbor (NAP 2003). The unique attributes of this fen and its rarity as a wetland type provide justification for its restoration to previous size and species composition. This restoration plan proposes management strategies that will regain this fen’s former extent and quality of native vegetation. If implemented, this 45

restoration will not only preserve and expand a valuable natural wetland with unique species, it will also present land managers with an opportunity to learn how to better preserve fen wetlands. Additionally, this restoration will provide the University of Michigan with a valuable resource for teaching in the natural sciences.

Site Description

Location, Size, and Management Authority

Kirk’s Fen is located on the property of the University of Michigan’s Matthaei Botanical Gardens in Superior Township near the intersection of Plymouth Rd. and Dixboro Rd (Fig. 2). It is in the southwest quarter of section 18 (T. 2 S., R. 7 E.) to the west of Fleming Creek. The size of the fen in 1949 was approximately 0.73 ha. Ideally, an area twice that size (approximately 2 ha) would be managed to connect the fen with the surrounding landscape and eliminate nearby sources of invasive species that would serve as source of seed. The agency responsible for management at this site is the University of Michigan’s Matthaei Botanical Gardens and Nichols Arboretum.

Ecoregional Context and Physiography

Kirk’s Fen is located in Region I, Southern Lower Michigan, District 1, Washtenaw District, and subdistrict 3, Ann Arbor subdistrict according to the Regional Landscape Ecosystems of Michigan (Albert et al. 1986) giving the area distinct climate, physiography, and vegetation. The Washtenaw District has a growing season of 158 days, with mild winters. Precipitation is distributed evenly throughout the seasons. The Ann Arbor subdistrict is characterized by fine and medium textured end-moraine ridges and ground moraine separated by outwash channels containing local rivers and creeks. Fleming Creek is in one of these channels (Albert et al. 1986). Kirk’s Fen is near the intersection of an end moraine with medium textured till and an outwash plain consisting of sand, gravel and post glacial alluvium (MNFI 1998). This site has a south-southeastern aspect. It is situated on gently sloping land and is placed low on the slope running down to Fleming Creek and Kirk’s Brook. Elevation is approximately 244 m above sea level 46

(Washtenaw County 2003). Reid (1958) places this site on the upper floodplain of Fleming Creek bordered to the north by what he calls outwash uplands.

Soils

The Washtenaw County Soil Survey (Engel 1977) placed soils in this area in the Houghton series. This soil series is described as very poorly drained, with nearly level soils formed in organic deposits, in areas of lake plains, outwash plains, till plains and moraines. The soils are noted to have a very high available water capacity, with rapid permeability. More specifically, this source classifies the soil as Houghton Muck. This soil type describes soil in “depressional areas, broad low-lying areas, along waterways of lake plains, outwash plains, till plains, and moraines”, and areas irregular in size from 1.2 to 81 ha. The water table is high here and subject to flooding, with the runoff occurring slowly. Reid’s investigation of Matthaei’s soils (1958) also classified this area as Houghton Muck, and defines this type as an organic soil derived from fibrous containing little woody material. He also reports that peat depth in this area exceeds 2.7 m in places. Site investigations for this management plan revealed that the soils in Kirk’s Fen consisted of a mixture of mineral soils and sapric to fibric peat, mostly sapric, greater than 1.7 m in depth. See Table 6. In areas where shrubs have invaded the fen, the peat soil seems to have oxidized, causing the soil level to drop, exposing the roots of trees and shrubs.

Presettlement and Historic Vegetation

The areas surrounding Kirk’s Fen were likely wet prairie, oak hickory forest, and black oak barrens in presettlement times. Kirk’s Fen is located on the border of what was once oak hickory forest and wet prairie (Michigan Resource Information System 1978). Species listed in Table 9 may have been present at this site or in similar areas and native species listed may be considered for reintroduction at a latter date or may reappear with management. In fact, recent management activities in the adjacent Kirk Woods area to remove invasive plants have resulted in the return of native understory plants.

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Current Vegetation

A vegetation survey was conducted over a series of visits in August and September of 2004 and April, May, and June of 2005. A Floristic Quality Analysis of the site revealed a Floristic Quality Index score of 46.2. This score places Kirk’s Fen in a category that possesses sufficient conservatism and richness that makes it floristically important from a statewide perspective (Herman et al. 2001). Two state threatened species were present in the fen, Cypripedium candidum and Valeriana ciliata. Unfortunately, also present at this site were eighteen invasive species; among these were Lythrum salicaria and Rhamnus frangula, two species known to invade prairie fens (Spieles et al. 1999). The following is a list of invasives present at this site considered a threat to the fen in order of greatest to least threat: Rhamnus frangula, Rhamnus cathartica, Lythrum salicaria, Alliaria petiolata, Cirsium vulgare, Cirsium arvense, Lonicera tatarica, Lonicera maakii, Rosa multiflora, and Hesperis matronalis. Phalaris arundinacea is also known to be problematic in restoration of fens and similar communites (Perry and Galatoswitch 2004) and is present at this site. The overstory of the fen is primarily Rhamnus spp., Larix laricina, and Carpinus caroliniana. Rhamnus spp. and various native and invasive shrubs dominate the understory. The groundcover in areas invaded by shrubs is a mix of native fen species stunted by lack of sunlight, and species typical of disturbed or upland sites. In the remaining uninvaded areas, Carex spp., Solidago ohioensis, and Valeriana uliginosa are dominant. See Table 2 for additional FQA data and Table 3 for a full species list.

Key Ecosystem Processes

Hydrology and fire are the main ecosystem processes responsible for the formation and maintenance of prairie fens in the landscape (Spieles et al. 1999). Again, a fen is a type of wetland whose vegetation, water chemistry, and soil development are determined by groundwater flow. In fact, fens can develop only where groundwater continuously saturates soil at the surface (Bedford and Godwin 2003). Reid (1958) states that in the area of Kirk’s Fen “downward percolation of groundwater from the outwash uplands is impeded here by the presence of clays and clay silts beneath the bog peats 48

which thus permits the continued accumulation of bog sediments.” Fires were common in fens in presettlement times and were responsible for maintaining their open structure by inhibiting shrub invasion (Curtis 1971). Fires started in the upland oak savannas, barrens, and prairies by Native Americans or lightning then spread to the fens and burned surface vegetation (Spieles et al. 1999).

Land Use History and Ecosystem Change

Native Americans formally ceded the land on which Kirk’s Fen is located to the federal government in 1816. This site parcel was originally described in the first surveys as openings rather than dense woodlands, which is indicative of frequent fires perhaps set by Native Americans. Many settlers described the condition of the area as being oak openings and quotes indicate the land was burned on a regular basis. The Cummings Marsh area, the name the fen is given on earlier maps of the Matthaei Botanical Gardens, was used for grazing, and the site may have had some farming. This land was in the possession of the Matteson family from 1824 until the University bought the property in 1958 (“Matteson Farm” 2003). An early indication of the floristic value of this area comes from a letter written by Dr. Warren Wagner, the Director of the Matthaei Botanical Gardens at the time. In describing the unique attractions that the Gardens has to offer, he mentions the area just east of our fen site, then called Sinclair Bog, as being “notable for its native orchids and location as a hillside seepage area” (Wagner et al. 1967). Though not specifically referring to our site, many of the same species are likely to have been present here as well, as the conditions are similar. As previously mentioned, presettlement vegetation in this area was a mosaic of oak barrens, oak hickory forest, and wet prairie. Present fen vegetation is dominated by invasive Rhamnus spp. shrubs. Analysis of aerial photographs from 1949 to 2002 reveal a decrease in the amount of open graminoid dominated area in Kirk’s Fen because of shrub establishment. Shrubs have slowly moved in from the exterior of the fen into the center. Size of the fen in 1949 was approximately 0.73 ha with the 2002 size equaling 0.09 ha, a reduction of 88% (See Table 8 and Figs. 5, 6, and 7). Observations of these same aerial photographs reveal surrounding land use has also changed. Since 1949, areas

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to the north and west near Kirk’s Fen have been transformed from agricultural fields into housing developments. Currently Kirk’s Fen is not actively managed and is occasionally visited by classes from the University of Michigan’s School of Natural Resources and Adult Education classes from the Matthaei Botanical Gardens and Nichols Arboretum. Nearby, just across Kirk’s Brook, a reconstructed prairie and oak openings area at Matthaei is being managed using shrub removal techniques and prescribed fire. Combining management efforts already underway at these sites with management needed in Kirk’s Fen will save time and resources.

Conservation Targets

The conservation targets for this restoration plan are the prairie fen wetland, two state threatened plant species, and one snake species listed as “special concern” in the state. Prairie fens are considered by the MNFI to have a state rank of S3 (Spieles et al. 1999); an S3 rank indicates the community is rare or uncommon in the state of Michigan. Cypripedium candidum is a threatened species and has a state rank of S2. Valeriana ciliata is also a threatened species with a state rank of S2. (Valeriana ciliata is classified by MNFI as Valeriana edulis var ciliata). An S2 state rank indicates a species is “imperiled in state because of rarity”… “or because of some factor(s) making it very vulnerable to extirpation from the state.” Sistrurus catenatus catenatus is a snake species of special concern in Michigan and is being considered for federal listing. Its state rank is S3S4, a split ranking placing the rank between S3 and S4. An S3 rank is rare or uncommon in the state, whereas an S4 rank is apparently secure in the state (MNFI 2005). By restoring Kirk’s Fen, a rare wetland type will be maintained and the threatened and special concern species which rely on this wetland type for survival will be protected. Also, these conservations targets will be preserved for future generations of the general public and student visitors to the Matthaei Botanical Gardens. See Appendix A for a summary of the biology and management considerations for each threatened or special concern species.

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Stresses

Stresses are factors that have altered the ecological processes that maintained the prairie fen in pre-European settlement condition and currently threaten the existence of the conservation targets (Palmgren 2003). Following are the major stresses and the sources of those stresses known or thought to be acting on Kirk’s Fen. Chief among these stresses are the absence of fire and altered vegetation, particularly invasive species. Altered hydrology and nutrient addition are possible stresses that should be investigated further to understand the extant of their impact. The stresses and their effects on the fen are often positively reinforcing with the results of one stress intensifying the effects of another.

Altered Hydrology

Hydrology, specifically groundwater flow to the surface, is the main factor driving the formation of fens in the landscape. Thus, alterations of the hydrology of an area can have large impacts on prairie fens. Onsite investigations for this report detected no drainage tiles or ditches altering the hydrology of Kirk’s Fen. However, other modifications to the surrounding landscape since settlement, the source of this stress, have likely altered the amount of water reaching the fen through surface flow and groundwater flow. Unfortunately, just how much the hydrology has been altered is impossible to determine due to lack of baseline measurements prior to changes in the watershed. Changes in the proportion of surface water to groundwater reaching a fen have been shown to create large changes in pH (Glaser et al. 1990) which may then alter nutrient availability, plant establishment and reproduction. Groundwater flow to the fen may be altered by extraction of water from nearby wells or drains (Spieles et al. 1999). Lack of recharge to the water table would also change the amount of groundwater reaching the fen and could result through the draining of surface water (Spieles et al. 1999) or the inability of water to pass through impervious surfaces such as roads or concrete. Development that has occurred in the area, especially in the last 60 years, has increased the amount of impervious surface and may therefore be limiting recharge of the water table. Spieles et al. (1999) report that many prairie fens with disrupted recharge 51 areas experience shrub invasion. The lack of intact natural communities upslope of the fen may inhibit recharge of the ground water and lead to increased surface water runoff high in nutrient and sediment content which further alter the fen habitat. An additional source of stress altering the hydrology of the wetland is the establishment of shrubs in the fen. Shrubs establishing in Kirk’s Fen further alter the hydrology by lowering the water table through transpiration and canopy interception (Jacobson et al. 1991). Additional investigations are needed to determine the extent of the disruption to the hydrology of Kirk’s Fen.

Absence of Fire

Fire was a main factor in structuring prairie fen vegetation, and was responsible for sustaining their characteristic open structure by inhibiting shrub invasion (Curtis 1971). Fire suppression of both natural and Native American set fires likely began when this area was settled in the mid 1820’s (Hanley 1960) and has been an additional stress to the fen. This absence of fire has allowed the establishment of shrubs and likely altered the proportions of forb and graminoid components in the fen. Lack of fire favors graminoid species dominance; forb species need fire to create sites for establishment and germination and to maintain their presence in the seedbank (Kost and DeSteven 2000).

Nutrient Addition

The source of this stress is human-caused nutrient addition to fens, particularly through faulty septic tanks and fields (Panno et al. 1999) and agricultural runoff (Drexler and Bedford 2002). Older homes surrounding Kirk’s Fen may have septic tanks and fields contributing to this stress. Nutrients may reach the fen through groundwater, surface water, precipitation, and dry deposition and increased nutrient levels have been shown to have a negative impact on the diversity of bryophytes and vascular plants in reaction to this nutrient addition (Drexler and Bedford 2002). Drexler and Bedford suspect that diversity is decreased by nutrient addition through greater competition and productivity of a small number of plants that crowd and shade out smaller, less competitive species. Panno et al. (1999) suspect that excess nutrients supplied through 52

septic leakage leads to the dominance of invasives including those deemed large threats to fens: Typha angustifolia, Lythrum salicaria, and Phragmites australis. Green and Galatowitsch (2002) also report nutrient enrichment may lead to declines in species richness and lead to dominance by invasives. Deer trails also provide nutrient pathways into fens (Crum 1988) and a large amount of deer in an area may contribute to greater levels of nutrient addition and availability. An additional source of nutrient addition changing the on-site nutrient cycling is through the decomposition of the leaves of some shrubs found on the site. Heneghan et al. (2004) found Rhamnus cathartica’s leaves decompose rapidly and enrich soil in uplands with nitrogen possibly helping to maintain its dominance; pH was also found to be higher underneath these shrubs. They suggest soil food webs and nutrient cycling may be affected by this addition and that restoration projects in areas once dominated by R. cathartica may need to examine the nutrient levels in the soil. If nitrogen levels are found to be high, this could prove detrimental to restoration of native vegetation. R. frangula, also present in the fen, may have similar effects on fen soils. Investigations into the amount of nutrient cycling in Kirk’s Fen would reveal whether nutrient addition is truly a threat to this site. Use of road salt, fertilizers and pesticides on the surrounding properties are other possible sources of nutrient addition.

Altered Vegetation

The stresses mentioned above, absence of fire, altered hydrology, and nutrient addition are stresses that lead to alterations in the vegetation of the fen. An additional source, introduction of invasive species, particularly Rhamnus spp., has worked in concert with the previously mentioned sources of stress and together have altered the structure and composition of the vegetation in Kirk’s Fen. Kirk’s Fen may be particularly susceptible to invasion because of its proximity to roads and development. Invasive species introduced into a fen can have a wide range of effects including: alteration of habitat structure, lowered biodiversity, changes in number and quality of species, altered hydrology and nutrient cycling, increased productivity, and modified food webs (Zedler and Kercher 2004). Invasives can also change fuel properties in an ecosystem resulting in altered fire behavior and frequency (Brooks et al. 2004). Among 53 the more problematic species affecting fens in the Midwest are Rhamnus frangula (and R. cathartica), Phalaris arundinacea, Lythrum salicaria, and Phragmites australis. Often these invaders form monocultures that out compete native plants for nutrients and alter the habitat structure by shading out low-growing sun-loving species. Shrubs have established in approximately 88% of the fen since 1949 in areas that were once open and dominated by graminoids (See Figs. 6 and 7). The central, open portions of the fen not dominated by Rhamnus spp. are the only areas of the fen where native fen vegetation is still dominant. Threatened species found at this site, Cypripedium candidum and Valeriana ciliata, are also found only in the open portions of the fen. Here vegetation is predominantly forbs and graminoids with occasional shrubs; vegetation height is less than one meter and full sun is available throughout the year. Invasive species are present in the open portions and include small individuals of Lythrum salicaria and Rhamnus frangula. In the peripheral, shrub dominated area, Rhamnus frangula and Rhamnus cathartica reach heights of four meters or more and block sunlight from reaching the ground. Groundcover is sparse and species present are more typical of uplands, disturbed ground, and low light conditions; Phalaris arundinacea is present in small patches. Where these two sections grade into each other, stunted individuals of species found in the open portions of the fen, such as Potentilla fruticosa, Allium cernuum, and Carex spp. are present.

Potential for Success of Restoration

The potential for success of Kirk’s Fen restoration is promising. Hydrology of the site does not seem to have been altered by ditching or drainage tiles. Rivulets of running water on the surface and springs discharging into Fleming Creek are visible signs that groundwater is still feeding the fen. Lowered water table levels present are likely caused by the presence of shrubs covering the majority of the site, and once removed the water levels will rise, creating favorable conditions for native species and unfavorable conditions for some invasives. Based on the presence of open fen habitat still remaining and the groundcover of the shrub dominated areas still containing vegetation typical of fens, it is likely that a seed bank remains to revegetate the area after shrub removal. A combination of invasive species removal and management with prescribed fire will help 54 to return this area to its former size and quality. If left unmanaged, this site will likely be overtaken by shrubs in less than 10 years and the unique species that occupy this wetland will be lost. Restoration measures should begin as soon as possible, as it is generally unknown how long a native seed bank can persist on a site like this. Given the rarity of the prairie fen wetland type and the species that occur here, the value of restoring this site should not be understated.

Goals, Objectives, and Tasks

1) Main Goal: Restoration and protection of the prairie fen and the rare species found there.

Objective: Open the herbaceous area of Kirk’s Fen to its approximate 1949 boundary.

Tasks: • Cut and remove all native and non-native shrubs from the area in the winter, treating the stumps with herbicide. • Stack cut shrubs in brush piles and burn in the winter.

Objective: Reintroduce fire as a process within the fen.

Tasks: • One year after removing shrubs from within the 1949 boundary of the fen, begin a prescribed fire program. • Monitor the results of the fire, repeating burns as necessary to encourage native vegetation.

Objective: Increase populations of Cypripedium candidum, Valeriana ciliata, and Sistrurus catenatus catenatus.

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Tasks: • Establish baseline surveys of these plants and animals. • Manage fen for an open vegetation structure with few, patchy shrubs. • Monitor deer browse on C. candidum and V. ciliata and protect plants with deer fencing if necessary. • Develop routine surveying procedures. • Consider expanding the populations of the plant species through propagation if necessary.

Objective: Begin restoration and management in the surrounding wetlands and uplands to reconnect Kirk’s Fen with the surrounding landscape within ten years.

Tasks: • Remove invasive shrubs from surrounding wetland and upland areas. • Reintroduce fire as a process within the surrounding areas.

Objective: Elimination of invasive and problematic species. High priority species include: Rhamnus frangula, Rhamnus cathartica, Lythrum salicaria, Phalaris arundinacea, Alliaria petiolata, Cirsium arvense, and Cirsium vulgare. Secondary species include: Typha latifolia, Hesperis matronalis, Lonicera spp., Rosa multiflora, and Berberis thunbergii.

Tasks: • Treat invasives with removal techniques including hand-pulling, herbicide application, and torching of seedlings. • Monitor invasive populations and continue treatment if necessary.

2) Goal: Involvement of volunteers in the restoration process, including surrounding landowners and the neighboring community, as a means of gaining community support and assistance in monitoring and restoration activities.

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Objective: Establish a dedicated and knowledgeable volunteer base.

Tasks: • Recruit volunteers from the current Matthaei volunteer base, the University of Michigan, and other sources to assist in monitoring and restoration activities. • Contact surrounding landowners and neighboring community and supply them with educational materials about the fen and a request to aid in the restoration of Kirk’s Fen through donations or volunteering of their time.

3) Goal: Utilize Kirk’s Fen in the education programs of Matthaei Botanical Gardens and Nichols Arboretum.

Objective: Educate staff of Matthaei Botanical Gardens and Nichols Arboretum concerning the need for the restoration of Kirk’s Fen to improve their ability to educate visitors and the public about this project.

Tasks: • Hold a staff meeting before the implementation of the restoration to present details of the restoration to the staff. • Periodically update the staff on the progress of the restoration.

Objective: Encourage faculty at the University of Michigan, and teachers in the education programs at the Matthaei Botanical Gardens and Nichols Arboretum to use the fen in teaching.

Tasks: • Announce this restoration to appropriate groups of educators. • Provide background information in a form that can be disseminated.

4) Goal: Encourage on-going research on prairie fens and their management at Kirk’s Fen. 57

Objective: Announce the implementation of this restoration to appropriate departments at the University of Michigan who may be interested in research on any aspect of the fen.

Tasks: • Develop an effective form of disseminating this information.

Objective: Establish process for routinely collecting data on the fen to compare with baseline information and for use in follow-up studies.

Tasks: • Develop monitoring protocols for specific species or data of interest. • Develop a database or system to store information on the fen for use in future studies.

Suggested Restoration Strategy

Management in Kirk’s Fen should begin immediately to ensure that this unique wetland is not completely overtaken by Rhamnus spp. Needs of the threatened plant species, Cypripedium candidum and Valeriana ciliata, and the snake species of concern, Sistrurus catenatus catenatus were taken into account in the formation of this plan. A synopsis of their individual management needs can be located in Appendix A. For specific information on removal strategies for individual invasive species see Appendix B. During the first year of restoration, before shrub removal, the entire area should be cleared of Phalaris arundinacea during the growing season. This species is known to be problematic in the restoration of fens and similar ecosystems. Also during this first season, individuals of Lythrum salicaria and Typha latifolia should be removed as the populations are small and these species may spread as more suitable habitat is made available by shrub removal. The first winter, the entire area within the 1949 shrub boundary should be cleared of all woody shrubs and trees, native and non-native except 58

Larix laricina and Juniperus virginiana as they are often naturally occurring in fens. The primary targets of this shrub removal are the invasive species present at this site, particularly Rhamnus spp. However, clearing all woody trees and shrubs, aside from those mentioned earlier, will prevent the accidental leaving of some invasive shrubs on site. Lack of need for correct identification of woody plants also will make work easier for individuals unfamiliar with plant identification. Larix laricina and Juniperis virginiana are conifers and should be easily distinguished by personnel with minimal training. An additional benefit to clearing all woody trees and shrubs at once is that the water levels in the fen will rise due to the lack of shrub transpiration in the growing season, creating more beneficial conditions for the establishment of native fen vegetation. In addition to removing the shrubs, water table levels may rise if the streambed of Kirk’s Brook is raised. In-channel stream-slowing and sediment-trapping measures should be explored to determine how to reverse the down-cutting that has occurred. Lack of shrubs in the area will also initially reduce perching sites for birds that may introduce unwanted species in their droppings. Shrubs should be piled on site and burned in cleared areas lacking native fen vegetation to avoid damaging populations that will contribute to the revegetation of the fen. Burning of shrub piles should be conducted during the winter months when snow is present to reduce the impact on the peat soil. Cut stumps could later be cut to ground level after the herbicide has killed the shrubs to avoid future hazards. It is likely that some Rhamnus spp. stumps may resprout after treatment. For this reason the area should be revisited following treatment and any resprouts or individuals found should be retreated until the area is free of this pest. Initially, two areas in Kirk’s Fen should receive separate burn regimes. One area would include the high quality, open portions of the fen not invaded by Rhamnus spp. and dominated by native species and the other area would include that cleared of all woody shrubs. In both areas, prescribed burning should begin in the spring following shrub removal. Burning should take place in the early spring, near the end of April, with back fires to avoid death of massasaugas. This suggested April burn time goes against the management recommendations made for Sistrurus catenatus in Appendix A. However, this is justified because of the advanced invasion of Rhamnus spp. in Kirk’s Fen and the need for their control. Once the area has been reclaimed and is nearly free of these pests, management should adjust to match the suggested recommendations in 59

Appendix A. If hibernacula are found or their locations are known, burning should not occur within 50 m of them during this time. These proposed burn areas are small and should be walked through prior to burning to clear snakes from the area. In the high quality, open portions of the fen, approximately one third of the area should be burned the first spring, during the end of April. This first burning should include the area where the population of C. candidum is found to expedite its recovery. Because of the low numbers of individuals, careful monitoring of the area containing C. candidum should be conducted to determine the appropriate return interval of fire. Each year, a different third of the high quality area should be burned with a three to five year return interval between burning in one section. In the areas cleared of shrubs, any portion with enough fuel to carry a fire should be burned the first spring. Annual spring burning of the cleared area should occur for the first five years or more if needed to rid the seedbank of invasive species and aid in the return of native vegetation. To control the large amount of buckthorn seedlings that are likely to sprout after shrub removal, spot- burning of dense patches of seedlings with a propane torch should be conducted in the first growing season and during subsequent seasons until enough fuel is present to carry a prescribed fire. Once the cleared area has been rid of the majority of Rhamnus spp. seedlings and sprouts, and resembles the areas dominated by native fen vegetation, then burning of the entire fen should be conducted as follows: one third of the entire fen should be burned each year for three consecutive years. The long-term goal should be to burn each third every three to five years. Patchy burning will allow the return of native shrubs in a natural mosaic pattern characteristic of fens. Removal of herbaceous invasive species should take place throughout the growing season annually for the first five years and longer if needed, according to instructions given in Appendix B. Efforts to remove these species should be especially diligent in the first five years as native fen vegetation may be initially slow to regain dominance. If after a period of two to three years native vegetation is slow to return to the cleared areas, establishment of native species could be assisted by spreading seed collected on site or from Radrick Fen. Species selected for seed gathering and sowing should include a wide variety of species, not just prairie fen dominants. Native species common in fens and listed in Tables 3 and 5 should be targeted for collection. Seeding 60

would occur throughout the year in stages, depending on the particular species being sown. Once native vegetation characteristic to fens returns to 75% of the area, management should move into the surrounding uplands to regain a healthy mosaic of ecosystem types and reconnect Kirk’s Fen with the landscape. All management techniques and strategies in Kirk’s Fen should be reviewed annually for possible modification, as unexpected results may arise in the restoration process. A visual representation of annual tasks can be seen in Table 10.

Alternative Management

Alternatives to the suggested course of action do exist and should be considered, though the previously stated strategy will likely bring about the quickest recovery to Kirk’s Fen. Two alternatives to shrub removal could be considered. First, removing only invasive shrubs from the area once open in 1949 could be conducted. This is not recommended for many reasons: 1) identification of individual species would require a much more skilled work force to remove only certain species of plants; 2) removing only some shrubs increases the likelihood that invasives shrubs would be left on site; 3) leaving only native shrubs would make maneuvering and removing other shrubs difficult and no cleared areas would be available for burning brushpiles; 4) native shrubs are present in Kirk’s Fen in increased number and density that are not typical of fens because of fire suppression; and finally 5) leaving native shrubs on site will prevent the return of higher water table levels because of continued high levels of evapotranspiration. The second option for shrub removal would be to remove the shrubs in stages, beginning with the areas nearest to the still open portions of the fen or with high amounts of remaining fen vegetation in the groundcover. This strategy would require less manpower and effort each year; however the following disadvantages exist: 1) leaving areas covered with trees and shrubs contributes to the loss of viable seed and plant material that would serve to revegetate the fen; 2) invasive shrubs left near the cleared areas would supply a seed source for reinvasion; 3) leaving a portion of all woody plants on site would prevent the return of higher water levels because of continued high levels of evapotranspiration.

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Monitoring

As initially stated, the management activities for Kirk’s Fen would have the main goal of restoring and protecting the prairie fen and the rare species found there. To determine the effectiveness of management techniques being used, monitoring is a necessity. Monitoring suggested here is meant to balance scientific rigor with staff availability and expertise. Information gathered during monitoring will supply those making management decisions with enough information to determine whether current management techniques are achieving the expected response, or if new techniques should be investigated. If further detail is needed, a standard scientific sampling design should be devised with the objectives of the monitoring clearly stated. Effective monitoring of vegetation response to management at Kirk’s Fen will lead to informed management decisions concerning this prairie fen and the threatened species that occur here. See Table 10 for a listing and timing of yearly monitoring activities.

Threatened and Special Concern Species

The threatened plant species present, Cypripedium candidum and Valeriana ciliata, should be monitored annually. Each year, boundaries of their populations should be mapped using GPS equipment. This information would then be entered in to a GIS database and the increase or decrease of the population boundaries could be tracked yearly. Maps created by GIS would also allow for easier location of previous patches of threatened species and reduce search time in subsequent years. Numbers of blooming individuals should also be recorded annually for each species, during late May and early June. Any sighting of Sistrurus catenatus catenatus in or around the fen area should be documented. Documentation should include the date, location, weather and any other information to add in the knowledge of the snake’s use of the areas. This information will aid future management decisions. See Appendix A for additional information on the threatened and special concern species.

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Invasive and problematic species

All invasive and problematic species should be monitored annually during the first five years of restoration in Kirk’s Fen and biannually thereafter. Records should be kept on which species or populations were treated with fire or herbicide and whether or not that treatment was effective. Each year, boundaries of their populations should be mapped using GPS equipment. This information would then be entered in to a GIS database and the increase or decrease of the population boundaries or the occurrence of new populations could be tracked yearly. Maps created in GIS would also allow for easier location of previous patches of invasive species and reduce search time in subsequent years. Effectiveness of cutting and herbicide treatment of shrubs could be determined by creating three permanently marked, randomly placed areas with approximately 50 stems each. Shrubs would then be cut and treated in the winter during initial clearing of the site. During the following growing season, the stumps in these areas would be examined for sprouting, and recorded as either dead or sprouting. This measurement would then allow for estimates of successful herbicide kill.

Other Monitoring

Twice annually an inventory of plant species should be conducted during the first five years and every two to three years thereafter as plants not seen at a site for years have been known to reappear after management. Inventories should occur once in the spring and once in the late summer to ensure the inclusion of both early and late blooming species. Plant species listed in Table 11, should be paid special consideration if found in the fen as they are considered rare and are associated with prairie fens. A Floristic Quality Analysis can then be preformed on this list to track the change in quality of the fen flora. This will allow managers to see if any species, native or non-native, are being added to the community because of management and if management is having any effect on the quality of the area. Photomonitoring from points marked by GPS should be used to document the sites before and after any management activities are conducted, such as prescribed burning and herbicide application to invasive species. Also, 63

groundwater wells installed throughout the site and measured at least weekly would enable the effect of shrub removal on the water table levels to be monitored and allow the possibility of water quality testing in the future.

Indicators of a Successful Restoration

The following list of indicators of successful restoration has been adapted from Woods (2003) to be relevant to Kirk’s Fen. If these conditions are present, restoration may potentially be considered successful.

1) All stands of Rhamnus spp. have been cleared from the fen, eliminating the seed producing plants and minimizing the possibility of dispersal to new areas.

2) Rhamnus spp. seedlings have been suppressed with prescribed burns or incineration with a propane torch, resulting in lower numbers of germinating seeds in restored areas.

3) Herbicide treatment has minimized resprouts, resulting in greater than 80% mortality after initial treatment.

4) Rhamnus frangula, Rhamnus cathartica, Lythrum salicaria, Phalaris arundinacea, Alliaria petiolata, Cirsium arvense, Cirsium vulgare, Typha latifolia, Hesperis matronalis, Lonicera spp., Rosa multiflora, and Berberis thunbergii have been eliminated within the 1949 fen boundary and the surrounding areas.

5) Species typical of upland sites have disappeared within the fen, indicating greater soil saturation.

6) Ground water levels in wells have increased.

7) Population data has been established for Cypripedium candidum, Valeriana ciliata, and Sistrurus catenatus catenatus and increases have been observed in the number of individuals and the number of populations for these species. 64

8) Increases of fen indicator species have been observed (See Table 1)

9) Longer lines of site are noticeable in the fen because of reduction in shrub dominance.

10) Increases in the ratio of grassland birds to forest edge species.

11) 25% of Kirk’s Fen has been buffered by restored ecosystems.

12) A dedicated volunteer committee persists.

13) Down cutting of Kirk’s Brook has been stopped and the level of the streambed has been raised.

Reference system

The Society for Ecological Restoration (2004) recommends the designation of a reference ecosystem in restoration projects. This reference ecosystem helps to serve in the planning and evaluation of restoration activities. Radrick Fen can serve as a reference ecosystem for the restoration of Kirk’s Fen for comparisons of species composition, vegetation structure, or other ecosystem attributes. Other quality fens that exist in the Ann Arbor area such as Park Lyndon North, managed by the Washtenaw County Parks and Recreation Commission, or the fens managed by the Natural Area Preservation Division of the City of Ann Arbor Public Services Area could also be used as references.

Suggested Further Studies

There are limitless studies that would help add to the knowledge of Kirk’s Fen specifically and more generally to the knowledge base of managing fens and the unique species found in them. These studies should be encouraged at Kirk’s Fen. Further inventories of organisms aside from vascular plants should be conducted. Especially insects, bryophytes, and land snails as fens are known to support rare species in these 65

groups (Bedford and Godwin 2003). Presence of rare species not now known in the fen may affect management strategies. Species listed in Table 11 should be paid special consideration if found in the fen as they are considered rare and are associated with prairie fens. Additionally, more in depth studies are needed on the use of Kirk’s Fen by Sistrurus catenatus catenatus. A telemetry study similar to Hallock’s (1991), but on a much larger scale would help determine hibernacula locations and habitat use and assist in future management decisions. Hydrology is a driving factor in the formation of fens, and little is known about the groundwater in the area of Kirk’s Fen. Research should be conducted to determine the location of the recharge area of the fen. If this is known, it can be determined if the recharge area has been affected by development, and if the amount of water reaching the fen has been reduced from historic levels. Water quality monitoring should also be conducted. Increased levels of nutrients in the water reaching the fen could have large impacts on the revegetation of the site.

Recommended Use

Future use of the site should be limited to small groups of individuals led by trained volunteers, educators, or employees of the Matthaei Botanical Gardens and Nichols Arboretum. Small groups will minimize trampling of the peat soils, possibly limiting the opportunity for invasion by unwanted species. Also, restricting public access to Kirk’s Fen will minimize the impact of human disturbance on the small populations of threatened and special concern species present.

Conclusion

Restoration of Kirk’s Fen is an opportunity to restore a rare wetland type, the prairie fen, while simultaneously protecting populations of threatened and special concern species and expanding their possible habitat. With this restoration Matthaei Botanical Gardens and Nichols Arboretum have an opportunity to restore one of the highest rated areas in the city as determined by the Floristic Quality Assessment. In a

66 time when many of Michigan’s high quality natural areas are being threatened by human alteration and introduction of invasive species Kirk’s Fen should be protected at all cost.

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Chapter Four: Radrick Fen Management Plan

Introduction

Radrick Fen at the University of Michigan’s Matthaei Botanical Gardens is another rare wetland in need of management to prevent its being overtaken by shrubs. Like Kirk’s Fen, Radrick Fen, is a prairie fen as defined by the Michigan Natural Features Inventory (MNFI). This fen type occurs only in the glaciated Midwest, and differs from other calcareous fens by the presence of a tallgrass prairie flora and fauna component (Spieles et al. 1999). MNFI lists prairie fens as being globally restricted in their range making them vulnerable to extinction, and rare or uncommon in the state of Michigan (MNFI 2005). This fen had approximately 0.81 ha of open graminoid dominated area in 1949. Since that time, the establishment of shrubs, both native and invasive, in this wetland has reduced the size of the open area of the fen to 0.56 ha. This 31% reduction has not severely altered the vegetation composition and structure in the fen, and the floristic quality of the area is very high, at 61.4 (Table 4). Probable reasons for this change in the vegetative structure of this fen are interrelated results of an altered fire regime, addition of invasive species, and possible changes in the hydrology of the area. The value of this fen to both the state of Michigan and the Matthaei Botanical Gardens is highlighted by the presence of two state threatened plant species and one snake species of special concern currently being considered for federal listing. Additionally, a Floristic Quality Assessment of the site registered a Floristic Quality Index ranking of 61.4. This score places Radrick Fen in a category of sites that are extremely rare examples of Michigan’s native biodiversity (Herman et al. 2001). Of six fens in Ann Arbor that have been evaluated using the FQA, this site scored the highest FQI ranking, and in fact is among the highest ranked of all sites of any community type measured in Ann Arbor (NAP 2003). The unique attributes of this fen and its rarity as a wetland type provide justification for its management to avoid further degradation of this site. Managing this site now will likely avoid higher costs if management is left until the situation worsens. This restoration plan proposes management strategies that will regain this fen’s former extent and protect the high quality of native vegetation present. If 68

implemented, this management will not only preserve and expand a valuable natural wetland with unique species, it will also present land managers with an opportunity to learn how to better preserve fen wetlands. Additionally, this management will provide the University of Michigan with a valuable resource for teaching in the natural sciences.

Site Description

Location, Size, and Management Authority

Radrick Fen is located on the property of the University of Michigan’s Matthaei Botanical Gardens in Ann Arbor Township. It is placed almost directly in the center of the continuous portion of land bound by Plymouth Rd. to the north, Dixboro Rd. to the west, Gale Rd. the east, and Geddes Rd. to the south (Fig. 2). It is in the southeast quarter of section 24 (T. 2 S., R. 6 E.) on the east side of Fleming Creek. The size of the fen in 1949 was approximately 0.81 ha. Ideally, an area twice that size (approximately 2 ha) would be managed to connect the fen with the surrounding landscape and eliminate nearby sources of invasive species that would serve as source of seed. The agency responsible for management at this site is the University of Michigan’s Matthaei Botanical Gardens and Nichols Arboretum.

Ecoregional context and Physiography

Radrick Fen is located in Region I, Southern Lower Michigan, District 1, Washtenaw District, and subdistrict 3, Ann Arbor subdistrict according to the Regional Landscape Ecosystems of Michigan (Albert et al. 1986) giving the area distinct climate, physiography, and vegetation. The Washtenaw District has a growing season of 158 days, with mild winters. Precipitation is distributed evenly throughout the seasons. The Ann Arbor subdistrict is characterized by fine and medium textured end-moraine ridges and ground moraine separated by outwash channels containing local rivers and creeks. Fleming Creek is in one of these channels (Albert et al. 1986). Radrick Fen is near the intersection of an end moraine with medium textured till and an outwash plain consisting of sand, gravel and post glacial alluvium (MNFI 1998). This site has a western aspect and 69

is situated on gently sloping land and is placed low on the slope running down to Fleming Creek. Elevation is approximately 236 m above sea level (Washtenaw County 2003).

Soils

The Washtenaw County Soil Survey (Engel 1977) placed soils in this area in the Sloan series. This soil series is described as very poorly drained, with nearly level soils formed in stratified loamy textured alluvial deposits, on the floodplains of streams and rivers. The soils are noted to have a very high available water capacity, with moderate permeability. More specifically, this source classifies the soil as Sloan Silt Loam, Wet. This soil type describes soil on alluvial floodplains of streams and rivers, and areas elongated in size from 2 to 101 ha. Included in this are other soils types including organic soils such as are found in Radrick Fen. The water table is high here and subject to flooding, with the runoff occurring slowly. Site investigations for this management plan revealed that the soils in Radrick Fen consist of a mixture of hemic to fibric peat, mostly fibric. The depth of peat in Radrick Fen ranged from 0.9 m to greater than 1.7 m in depth; over half of the depth measurements were less than 1.7 m. See Table 7.

Presettlement and Historic Vegetation

The areas surrounding Radrick Fen were likely wet prairie and oak hickory forest in presettlement times; Radrick Fen is located on what was once the border of these two ecosystem types (Michigan Resource Information System 1978). Species listed in Tables 9, 12, and 13 were either once recorded at this site or may have been present in similar areas and native species listed may be considered for reintroduction at a latter date.

Current Vegetation

A vegetation survey was conducted over a series of visits in August and September of 2004 and April, May, and June of 2005. A Floristic Quality Analysis of the site revealed a Floristic Quality Index score of 61.4. This score places Radrick Fen in a 70

category of sites that are considered extremely rare examples of Michigan’s native biodiversity (Herman et al. 2001). Two state threatened species were present in the fen, Sanguisorba canadensis and Valeriana ciliata. Unfortunately, also present at this site were Lythrum salicaria, Rhamnus frangula, and Phragmites australis, species known to invade prairie fens and alter vegetation composition (Spieles et al. 1999, Richburg et al. 2001, Gladwin 2003). Two other invasive species are present in the fen, Poa pratensis and Malus pumila, but are not thought to pose a threat at this time. The shrubs in the wooded zone surrounding the open areas of the fen consist primarily of Rhamnus frangula, Physocarpus opulifolius, and Carpinus caroliniana. The herbaceous layer in areas invaded by shrubs, as well in uninvaded open areas, is dominated by native species typical of prairie fens. In the open areas of the fen Carex spp., Schoenoplectus acutus, Valeriana uliginosa, and Sanguisorba canadensis are dominant. See Table 4 additional FQA data and Table 5 for a full species list.

Key Ecosystem Processes

Hydrology and fire are the main ecosystem processes responsible for the formation and maintenance of prairie fens in the landscape (Spieles et al. 1999). Again, a fen is a type of wetland whose vegetation, water chemistry, and soil development are determined by groundwater flow. In fact, fens can develop only where groundwater continuously saturates soil at the surface (Bedford and Godwin 2003). Fires were common in fens in presettlement times and were responsible for maintaining their open structure by inhibiting shrub invasion (Curtis 1971). Fires started in the upland oak savannahs, barrens, and prairies by Native Americans or lightning then spread to the fens and burned surface vegetation (Spieles et al. 1999).

Land Use History and Ecosystem Change

Radrick Forest, upslope from Radrick Fen, was heavily logged during the 1820’s. Fires may have occurred in Radrick Forest after logging and probably continued into the 1930’s (Barnes class notes); some of these fires likely extended into the fen. No grazing has occurred in this area since 1900, but little is known about grazing in the area prior to 71

this time (Barnes class notes). Gravel mining is also known to have occurred in the area between the forest and fen (Klatt 1999) and may have had an impact on the hydrology of the area. An indication that the wetland to the north of the fen may have been drained was discovered in the spring of 2005. Investigations for this report detected a drain tile underneath a newly fallen tree. This tile was located at the end of what looked like a natural stream draining the area to the north into Fleming Creek. An early indication of the floristic value of this area comes from a letter written by Dr. Warren Wagner, the Director of the Matthaei Botanical Gardens at the time. In describing the unique attractions that the Gardens has to offer, he mentions Radrick Bog, what we know as Radrick Fen, and the areas surrounding it as “exceptional natural areas of the highest quality” (Wagner et al. 1967). As previously mentioned presettlement vegetation in this area was wet prairie and oak hickory forest. Present fen vegetation is dominated by native herbs, shrubs and graminoids. Analysis of aerial photographs from 1949 to 2002 reveal a decrease in the amount of open graminoid dominated area in Radrick Fen because of shrub establishment. Shrubs have slowly moved in from the exterior of the fen towards the center. Size of the fen in 1949 was approximately 0.81 ha with the 2002 size equaling 0.56 ha, reduction of 31% (Table 8 and Figs 5, 8, and 9). Observations of these same aerial photographs reveal surrounding land use has not changed drastically and since 1949, perhaps contributing to the high quality state of Radrick Fen. Currently Radrick Fen is not actively managed and is occasionally visited by classes from the University of Michigan’s School of Natural Resources and Adult Education classes from the Matthaei Botanical Gardens and Nichols Arboretum.

Conservation Targets

The conservation targets for this management plan are the prairie fen wetland, two state threatened plant species, and one state snake species of special concern. Prairie fens are considered by the MNFI to have a state rank of S3 (Spieles et al. 1999); an S3 rank indicates the community is rare or uncommon in the state of Michigan. Valeriana ciliata is a threatened species and has a state rank of S2. An S2 state rank indicates a species is “imperiled in state because of rarity”…. “or because of some factor(s) making 72

it very vulnerable to extirpation from the state.” Sanguisorba canadensis is a threatened species with a state rank of S1. The S1 rank indicates this species is critically imperiled in the state because of extreme rarity or because of some factor making it vulnerable to extirpation in the state (MNFI 2005). Sistrurus catenatus catenatus is a state snake species of special concern being considered for federal listing. Its state rank is S3S4, a split ranking placing the rank between S3 and S4. An S3 rank is rare or uncommon in the state, whereas an S4 rank is apparently secure in the state (MNFI 2005). By managing Radrick Fen, a rare wetland type will be maintained and the threatened and special concern species which rely on this wetland type for survival will be protected. Also, these conservations targets will be preserved for future generations of visitors and students to the Matthaei Botanical Gardens. See Appendix A for a summary of the biology and management considerations for each threatened or special concern species.

Stresses

Stresses are factors that have altered the ecological processes that maintained the prairie fen in pre-European settlement condition and currently threaten the existence of the conservation targets (Palmgren 2003). Following are the stresses and the sources of those stresses known or thought to be acting on Radrick Fen. The stresses of absence of fire and altered vegetation are known to be acting on the fen. Altered hydrology and nutrient addition are possible stresses that should be investigated further to understand the extant of their impact. The stresses and their effects on the fen are often positively reinforcing with the results of one stress intensifying the effects of another.

Absence of Fire

Fire was a main factor in structuring prairie fen vegetation, and was responsible for sustaining their characteristic open structure by prohibiting shrub invasion (Curtis 1971). Fire suppression of both natural and Native American set fires, the source of the stress, likely began when this area was settled in the mid 1820’s (Hanley 1960). However, fires after the logging of Radrick Forest during this time may have extended into the 1930’s (Barnes class notes), but the fen has probably not burned since that time. 73

This absence of fire has allowed the establishment of shrubs and likely altered the proportions of forb and graminoid components in the fen. Lack of fire favors graminoid species dominance; forb species need fire to create sites for establishment and germination and to maintain their presence in the seedbank (Kost and DeSteven 2000). The stress of lack of fire is probably the single most important stress contributing to the changes occurring in Radrick Fen.

Altered Hydrology

Hydrology, specifically groundwater flow to the surface, is the main factor driving the formation of fens in the landscape. Thus, alterations of the hydrology of an area can have large impacts on prairie fens. Onsite investigations for this report detected no drainage tiles or ditches altering the hydrology of Radrick Fen. However, a drain tile was found just outside the area of this study, indicating that an attempt to drain the area to the north of Radrick Fen may have been made. It is likely that Radrick Fen’s hydrology is largely unaltered from its presettlement condition as indicated by its continued presence in a high quality state. However, modifications to the surrounding landscape since settlement, the source of this stress, may have altered the amount of water reaching the fen through surface flow and groundwater flow, resulting in the increased establishment of woody vegetation. Surface water flow to the fen may have been altered by construction of the road just east of the fen. Changes in the proportion of surface water to groundwater reaching a fen has been shown to create large changes in pH (Glaser et al. 1990) which may then alter nutrient availability, plant establishment, and reproduction. Quarrying activities are known to have occurred upslope from the fen (Klatt 1999), and are known to affect ground water flow (Bedford and Godwin 2003). Groundwater flow to the fen may also be altered by extraction of water from nearby wells or drains and lack of recharge to the water table (Spieles et al. 1999). An additional source of stress altering the hydrology of the wetland is the establishment of shrubs in the fen. Shrubs establishing on the edge of Radrick Fen alter the hydrology by lowering the water table through transpiration and canopy interception (Jacobson et al. 1991). A factor contributing to the health of Radrick Fen’s hydrology is the presence of intact natural communities upslope of the fen. Intact natural communities, such as 74

Radrick Forest, allow precipitation to recharge the groundwater zone which then contributes to groundwater flow to the surface of the fen. Many prairie fens with disrupted recharge areas experience shrub invasion (Spieles et al. 1999), and because of the positive influence Radrick Forest has on the hydrology of Radrick Fen, this forest should be protected from development. Further investigations are needed to determine the extent of the disruption to the hydrology of Radrick Fen.

Nutrient Addition

The source of this stress is mainly human caused nutrient addition to fens, particularly through faulty septic tanks and fields (Panno et al. 1999) and agricultural runoff (Drexler and Bedford 2002). Nutrients may reach the fen through groundwater, surface water, precipitation, and dry deposition and increased nutrient levels have been shown to have a negative impact on the diversity of bryophytes and vascular plants in reaction to this nutrient addition (Drexler and Bedford 2002). Drexler and Bedford suspect that diversity is decreased by nutrient addition through greater competition and productivity of a small number of plants that crowd and shade out smaller, less competitive species. Panno et al. (1999) suspect that excess nutrients supplied through septic leakage leads to the dominance of invasives including those deemed large threats to fens: Typha angustifolia, Lythrum salicaria, and Phragmites australis. Green and Galatowitsch (2002) also report nutrient enrichment may lead to declines in species richness and lead to dominance by invasives. Deer trails also provide nutrient pathways into fens (Crum 1988) and a large amount of deer in an area may contribute to greater levels of nutrient addition. Though sources of nutrient addition are possible, Radrick Fen’s isolation in the landscape makes these additions unlikely and a study in Radrick Fen by Gladwin (2003) revealed no detectable nitrates in the groundwater. An additional source of nutrient addition may be through the decomposition of the leaves of some shrubs found on site. Heneghan et al. (2004) found Rhamnus cathartica’s leaves decompose rapidly and enrich soil in uplands with nitrogen possibly helping to maintain its dominance; pH was also found to be higher underneath these shrubs. They suggest soil food webs and nutrient cycling may be affected by this addition and that restoration projects in areas once dominated by R. cathartica may need to examine the 75 nutrient levels in the soil. If nitrogen levels are found to be high this could prove detrimental to restoration of native vegetation. R. frangula may have similar effects on fen soils. Investigations into the amount of nutrient addition to Radrick Fen, if any, need to be conducted to recognize if this is truly a threat to this site.

Altered Vegetation

The stresses mentioned above, absence of fire, altered hydrology, and nutrient addition are sources of the stress of altered vegetation. An additional source, introduction and establishment of invasive species, has worked in concert with the previously mentioned sources of stress and have together altered the composition and structure of the vegetation in Radrick Fen. Invasive species introduced into a fen can have a wide range of effects including: alteration of habitat structure, lowered biodiversity, changes in number and quality of species, altered nutrient cycling, increased productivity, and modified food webs (Zedler and Kercher 2004). Invasives can also change fuel properties in an ecosystem resulting in altered fire behavior and frequency (Brooks et al. 2004). Among the more problematic species affecting fens in the Midwest are Rhamnus frangula (and R. cathartica), Phalaris arundinacea, Lythrum salicaria, and Phragmites australis, all of which are present in Radick Fen. Often these invaders form monocultures that out compete native plants for nutrients and alter the habitat structure by shading out low-growing sun-loving species. Structure of the fen has been altered by the establishment of shrubs both native and invasive due to lack of fire and possible hydrological alterations. Shrubs have established in approximately 31% of the fen since 1949 in areas that were once open and dominated by graminoids (See Figs. 8 and 9). In the open portion of the fen, vegetation is predominantly forbs and graminoids with occasional shrubs; vegetation height is less than one meter and full sun is available throughout the year. Threatened species found at this site, Sanguisorba canadensis and Valeriana ciliata, are found only in the open portion of the fen. Invasive species are present in the open portion and include small individuals of Lythrum salicaria and Rhamnus frangula and a large population of Phragmites australis. In the peripheral shrub dominated areas, native vegetation is still

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present in the groundcover. See Table 5 for a species list including invasive species present.

Potential for Success

The potential for management to protect and expand Radrick Fen is promising. Hydrology of the site is intact and does not seem to have been altered by ditching or drainage tiles. Rivulets of running water on the surface and springs discharging into Fleming Creek are visible signs that groundwater is still feeding the fen. Native fen vegetation is also present in all areas of the fen. A combination of invasive species removal and management with prescribed fire will help to return this area to its former size and maintain its high floristic quality. If left unmanaged, this site will likely continue to be invaded by shrubs and the populations of Lythrum salicaria and Phragmites australis will spread. If these events occur, Radrick Fen will slowly lose its unique flora. Given the rarity of the prairie fen wetland type and the species that occur here, the value of restoring this site should not be understated.

Goals, Objectives, and Tasks

1) Main Goal: Restoration and protection of the prairie fen and the rare species found there.

Objective: Open the herbaceous area of Radrick Fen to its approximate 1949 boundary.

Tasks: • Cut and remove all invasive shrubs from the area in the winter, treating the stumps with herbicide. • Stack cut shrubs in brush piles and burn in the winter.

Objective: Reintroduce fire as a process within the fen.

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Tasks: • One year after removing invasive shrubs from within the 1949 boundary of the fen, begin a prescribed fire program. • Monitor the results of the fire, repeating burns as necessary to encourage native vegetation.

Objective: Increase populations of Sanguisorba canadensis, Valeriana ciliata, and Sistrurus catenatus catenatus.

Tasks: • Establish baseline surveys of these plants and animals. • Manage fen for an open vegetation structure with few, patchy shrubs. • Develop routine surveying procedures.

Objective: Begin restoration and management in the surrounding wetlands and uplands to reconnect Radrick Fen with the surrounding landscape within ten years.

Tasks: • Remove invasive shrubs from surrounding wetland and upland areas. • Reintroduce fire as a process within the surrounding areas.

Objective: Elimination of invasive and problematic species, especially Rhamnus frangula, Lythrum salicaria, and Phragmites australis.

Tasks: • Treat invasives with removal techniques including hand-pulling, herbicide application, and torching of woody seedlings. • Monitor invasive populations and continue treatment if necessary.

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2) Goal: Involvement of volunteers in the restoration process, including surrounding landowners and the neighboring community, as a means of gaining community support and assistance in monitoring and restoration activities.

Objective: Establish a dedicated volunteer base.

Tasks: • Recruit volunteers from the current Matthaei volunteer base, the University of Michigan, and other sources to assist in monitoring and restoration activities. • Contact surrounding landowners and neighboring community and supply them with educational materials about the fen and a request to aid in the restoration of Radrick Fen through donations or volunteering of their time.

3) Goal: Utilize Radrick Fen in the education programs of Matthaei Botanical Gardens and Nichols Arboretum.

Objective: Educate staff of Matthaei Botanical Gardens and Nichols Arboretum concerning the need for the restoration of Radrick Fen to improve their ability to educate visitors and the public about this project.

Tasks: • Hold a staff meeting before the implementation of the restoration to present details of the restoration to the staff. • Periodically update the staff on the progress of the restoration.

Objective: Encourage faculty at the University of Michigan, and teachers in the education programs at the Matthaei Botanical Gardens and Nichols Arboretum to use the fen in teaching.

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Tasks: • Announce this restoration to appropriate groups of educators.

4) Goal: Encourage on-going research on prairie fens and their management at Radrick Fen.

Objective: Announce the implementation of this restoration to appropriate departments at the University of Michigan who may be interested in research on any aspect of the fen.

Tasks: • Develop an effective form of disseminating this information.

Objective: Establish process for routinely collecting data on the fen to compare with baseline information and for use in follow-up studies.

Tasks: • Develop monitoring protocols for specific species or data of interest. • Develop a database or system to store information on the fen for use in future studies.

Suggested Management Strategy

Management in Radrick Fen should begin immediately to ensure the continued high floristic quality of this unique wetland and to avoid further establishment of invasive species into the central portions of the fen. Needs of the threatened plant species, Sanguisorba canadensis and Valeriana ciliata, and the snake species of concern, Sistrurus catenatus catenatus, were taken into account in the formation of this plan. A synopsis of their individual management needs can be located in Appendix A. For specific information on removal strategies for individual species see Appendix B. The first winter, the entire area within the 1949 shrub boundary should be cleared of invasive woody shrubs; Pinus sylvestris and Picea glauca trees should also be 80

removed from the site as they were likely planted (T. Reznicek pers. comm.). Cut stumps could be cut to ground level after the herbicide has killed the shrubs to avoid future hazards. Shrubs should be piled on site and burned during the winter months when snow is present to reduce the impact on the peat soil. These brush piles should be placed in areas with little high quality vegetation to avoid damage to threatened plant species. Perhaps areas in the shrub border could be cleared especially for this purpose to avoid burning brush piles in the central portion of the fen. Placement of brush piles should also avoid locations of Sistrurus catenatus hibernacula if they are known. It is likely that some Rhamnus frangula will be left untreated and some treated stumps may also resprout. For this reason the shrub borders should be revisited following treatment and any resprouts or individuals found should be retreated until the area is free of this pest. Prescribed burning should begin in the spring following shrub removal. Approximately one third of the fen area should be burned the first spring, near the end of April. Burns should extend as far into the shrub borders as fuel levels allow. Each year, a different third of the open area should be burned with a three to five year return interval between burning in one section. All burning should take place in the early spring with back fires to avoid death of massasaugas. If hibernacula are found or their locations are known, burning should not occur within 50 m of them during this time. These proposed burn areas are small and should be walked through prior to burning to clear snakes from the area. Patchy burning will allow the return of native shrubs in a natural mosaic pattern characteristic of fens. If burning does not reduce the spread of native shrubs, they too may be cut and treated with herbicide to further open the fen. If a large amount of Rhamnus frangula seeds begin to sprout after the shrub removal and burning, propane torches should be used to burn the seedlings during the first growing season. Removal of herbaceous invasive and problematic species should take place throughout the growing season annually for the first five years according to instructions given in Appendix B. Efforts to remove these species should be especially diligent in the first five years and then continued as needed. Most importantly, the small patches of Lythrum salicaria should be removed, this could begin during the growing season prior to shrub removal. Once management has cleared all invasive shrubs within the 1949 boundary and prescribed fire has been introduced into the fen, management should move into the surrounding uplands to regain a healthy mosaic of ecosystem types and reconnect 81

Radrick Fen with the landscape. Historically, open areas of Radrick Fen may have extended further to the north. An increase in the size of the open fen area could be achieved by extending management in this direction. All management techniques and strategies in Radrick Fen should be reviewed annually for possible modification, as unexpected results may arise in the management process. A visual representation of annual tasks can be seen in Table 10.

Alternative Management

An alternative to the suggested course of action does exist and should be considered, though the previously stated strategy will likely bring about the quickest recovery to Radrick Fen. Shrub removal with in the 1949 boundary could include all shrubs, both native and invasive. This is not necessary initially as Radrick Fen’s reduction in size due to shrub encroachment has not been drastic and species are not in danger of being lost from the fen in the near future. Removing only invasive shrubs will lessen the amount of work needed to be done and also minimize the amount of brush piles burned in the fen. If prescribed fires do not reduce the cover of native shrubs in the shrub borders, they too can be removed by cutting and herbicide application. A benefit to removing all shrubs in an area would be the return of higher water levels in the borders due to less transpiration and canopy interception by the shrubs present.

Monitoring

As initially stated, the management activities for Radrick Fen would have the main goal of restoring and protecting the prairie fen and the rare species found there. To determine the effectiveness of management techniques being used monitoring is a necessity. Monitoring suggested here is meant to balance scientific rigor with staff availability and expertise. Information gathered during monitoring will supply those making management decisions with enough information to determine whether current management techniques are achieving the expected response, or if new techniques should be investigated. If further detail is needed, a standard scientific sampling design should 82 be devised with the objectives of the monitoring clearly stated. Effective monitoring of the response of vegetation to management at the Matthaei fen sites will lead to informed management decisions concerning these valuable habitats and the threatened species that occur there. See Table 10 for a listing of yearly monitoring activities.

Threatened and Special Concern Species

The threatened plant species present, Sanguisorba canadensis and Valeriana ciliata, should be monitored annually. Each year, boundaries of their populations should be mapped using GPS equipment. This information would then be entered in to a GIS database and the increase or decrease of the population boundaries could be tracked yearly. Maps created by GIS would also allow for easier location of previous patches of threatened species and reduce search time in subsequent years. Numbers of blooming individuals should also be recorded annually for each species, during late May and early June Any sighting of Sistrurus catenatus catenatus in or around the fen area should be documented. Documentation should include the date, location, weather and any other information to add in the knowledge of the snake’s use of the areas. This information will aid future management decisions. See Appendix A for additional monitoring information on the threatened and special concern species.

Invasive and problematic species

Populations of all invasive and problematic species should be monitored annually during the first five years of restoration in Radrick Fen and biannually thereafter. Records should be kept on which species or populations were treated with fire or herbicide and whether or not that treatment was effective. Each year, boundaries of their populations should be mapped using GPS equipment. This information would then be entered in to a GIS database and the increase or decrease of the population boundaries or the occurrence of new populations could be tracked yearly. Maps created in GIS would also allow for easier location of previous patches of invasive species and reduce search time in subsequent years. 83

Effectiveness of cutting and herbicide treatment of shrubs could be determined by creating three permanently marked, randomly placed plots with approximately 50 stems each. Shrubs would then be cut and treated in the winter during initial clearing of the site. During the following growing season, the stumps in these areas would be examined for sprouting, and recorded as either dead or sprouting. This measurement would then allow for estimates of successful herbicide kill.

Other Monitoring

An annual inventory of plant species should be conducted during the first five years and every two to three years after that as plants not seen at a site for years have been known to reappear after management. Plant species listed in Table 11, should be paid special consideration if found in the fen as they are considered rare and are associated with prairie fens. A Floristic Quality Analysis can then be preformed on this list to track the change in quality of the fen flora. This will allow managers to see if any species, native or non-native, are being added to the community because of management and if management is having any effect on the quality of the area. Photomonitoring from points marked by GPS should be used to document the sites before and after any management activities are conducted, such as prescribed burning and herbicide application to invasive species. Also, groundwater wells installed throughout the site would enable the effect of shrub removal on the water table levels to be monitored and allow the possibility of water quality testing in the future.

Indicators of a Successful Restoration

The following list of indicators of successful restoration has been adapted from Woods (2003) to be relevant to Radrick Fen. If these conditions are present, restoration may potentially be considered successful.

1) All stands of Rhamnus spp. have been cleared from the fen, eliminating the seed producing plants and minimizing the possibility of dispersal to new areas.

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2) Rhamnus spp. seedlings have been suppressed with prescribed burns or incineration with a propane torch, resulting in lower numbers of germinating seeds in restored areas.

3) Herbicide treatment has minimized resprouts, resulting in greater than 80% mortality after initial treatment.

4) Rhamnus frangula, Phragmites australis, and Lythrum salicaria, have been eliminated within the 1949 fen boundary and the surrounding areas.

5) Species typical of upland sites have disappeared within the fen, indicating greater soil saturation.

6) Ground water levels in wells have increased.

7) Population data has been established for Sanguisorba canadensis, Valeriana ciliata, and Sistrurus catenatus catenatus and increases have been observed in the number of individuals and the number of populations for these species.

8) Increases of fen indicator species have been observed (See Table 1)

9) Longer lines of site are noticeable in the fen because of reduction in shrub dominance.

10) Increases in the ratio of grassland birds to forest edge species.

11) 25% of Radrick Fen has been buffered by restored ecosystems.

12) A dedicated volunteer committee persists.

Suggested Further Studies

There are limitless studies that would help add to the knowledge of Radrick Fen specifically and more generally to the knowledge base of managing fens and the unique 85 species found in them. These studies should be encouraged at Radrick Fen. Further inventories of organisms aside from vascular plants should be conducted. Especially insects, bryophytes, and land snails as fens are known to support rare species in these groups (Bedford and Godwin 2003). Presence of rare species not now known in the fen may affect management strategies. Species listed in Table 11 should be paid special consideration if found in the fen as they are considered rare and are associated with prairie fens. Additionally, more in depth studies are needed on the use of Radrick Fen by Sistrurus catenatus catenatus. A telemetry study similar to Hallock’s (1991), but on a much larger scale would help determine hibernacula locations and habitat use as restoration proceeds. Hydrology is a driving factor in the formation of fens, and little is known about the groundwater in the area of Radrick Fen. Research should be conducted to determine the location of the recharge area of the fen. If this is known, it can be determined if the recharge area has been affected by development, and if the amount of water reaching the fen has been reduced from historic levels. Water quality monitoring should also be conducted. Increased levels of nutrients in the water reaching the fen could have large impacts on the revegetation of the site.

Recommended Use

Future use of the site should be limited to small groups of individuals led by trained volunteers, educators, or employees of the Matthaei Botanical Gardens and Nichols Arboretum. Small groups will minimize trampling of the peat soils, possibly limiting the opportunity for invasion by unwanted species. Also, restricting public access to Radrick Fen will minimize the impact of human disturbance on the small populations of threatened and special concern species present.

Conclusion

Restoration of Radrick Fen is an opportunity to restore a rare wetland type, the prairie fen, while simultaneously protecting populations of threatened and special concern species and expanding their possible habitat. With this restoration Matthaei 86

Botanical Gardens and Nichols Arboretum have an opportunity to restore one of the highest rated areas in the city as determined by the Floristic Quality Assessment. In a time when many of Michigan’s quality natural areas are being threatened by human alteration and introduction of invasive species Radrick Fen should be protected at all cost.

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Concluding Remarks

Fens in general and prairie fens specifically, are rare wetlands that support a large amount of diversity when compared to other wetland types. These areas also often contain rare species. Unfortunately, prairie fens in Michigan are threatened by human activities in the landscape and their resulting consequences. In fens impacts include altered hydrology, nutrient addition, fire suppression, and changes in vegetation. As noted in this report, both Kirk’s Fen and Radrick Fen have had some level of degradation. Changes at Kirk’s Fen are much more severe with formerly open wetlands of high diversity now dominated by invasive shrubs. Changes at each site put populations of three state threatened plant species (Cypripedium candidum, Sanguisorba canadensis, and Valeriana ciliata) and one state species of special concern, the snake, Sistrurus catenatus catenatus, at risk. Not only are these sites inhabited by rare species, but they also have FQI scores ranking them among the highest rated sites in Ann Arbor. These high FQI scores and the presence of rare species indicate that not only are these sites valuable and important to protect in Ann Arbor, but also in the entire state of Michigan. The presence of threatened natural areas and species challenges Matthaei Botanical Gardens and Nichols Arboretum (MBGNA) with the responsibility to act quickly to protect and restore these special places. Furthermore, care of these areas will not only benefit MBGNA and its visitors. Monitoring conducted before and during the management and restoration activities will add to the knowledge of fen management and the effects of this management on the plants and animals that rely on this habitat to survive. Thus, land managers across the Midwest have the opportunity to learn how to better protect natural areas through the management of these sites. Additionally, the association of MBGNA with the University of Michigan offers many opportunities for research and teaching that will further the knowledge about these ecosystems and utilize them as laboratories for classes. Restoration of these areas also offers MBGNA an opportunity to encourage the protection and restoration of natural spaces in the community. The goal of this Master’s practicum was to create a restoration and management plan for the fens at Matthaei Botanical Gardens. This plan gives suggestions that targets restoration of the quality of vegetation and size of open areas in the fens that were present 88 in the 1950’s. The literature review of fens and their management, as well as the description of past and present conditions at Kirk’s Fen and Radrick Fen included in this practicum, will be useful to land-managers and future researchers at these sites specifically, as well those working with fens throughout the Midwest region. It is my belief that with vegetation management including a combination of cutting, hand-puling, herbicide treatment, and the use of prescribed fire, Kirk’s Fen, Radrick Fen and their unique native species can be preserved for future generations. Hopefully these recommendations are implemented immediately to expedite the recovery and preservation of these important wetlands.

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Appendix A:

Threatened and Special Concern Species: Biology and Management Recommendations

Aside from protecting the rare prairie fen wetland type, the proposed management and restoration of the fens at Matthaei Botanical Gardens are meant to protect and expand the populations of three threatened plant species and one snake species of special concern that occur in these sites. Following is a summary of each species’ pertinent biological information, a description of the location and status in each fen, and suggested management techniques.

Cypripedium candidum (white lady’s slipper)

Cypripedium candidum is a state threatened orchid with a state rank of S2, indicating that this species is imperiled in the state because of its rarity or because of some factor making it vulnerable to extirpation from the state (MNFI 2005). Prairie fens are the typical habitat for this species in Michigan, though it is also found in other wet and marly areas such as wet prairies (Higman and Penskar 1988). Falb and Leopold (1993) note that this species occurs only in sites with full sun or only light shade. C. candidum can spread by vegetative reproduction or by seed and Curtis (1943) reports that 12 years or more may be needed after germination to achieve maturity. This lag time between germination and maturation may make monitoring populations difficult over the short term. This orchid is currently found only in the remaining open areas of Kirk’s Fen. Weatherbee (1994) lists C. candidum as present in Radrick Fen in 1994; however, this plant is not present on a plant list of the fen conducted in 1999 by Reznicek et al. C. candidum is known to hybridize with Cypripedium calceolus, an orchid both historically (Wagner no date) and currently present in Radrick Fen, creating a hybrid of intermediate appearance, C. x andrewsii (Voss 1972). On the same list, probably compiled in the late 1960’s, Wagner lists the presence of C. x andrewsii but no C. candidum. No plants of intermediate appearance are now present in Radrick Fen (T. Reznicek pers. comm.). The population in Kirk’s Fen is very small. In 2003, only two small clumps were found with

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only two of the twelve individuals found in bud. Of these plants some stems appeared to be grazed by animals (Klatt and Weatherbee 2003). In 2005, during investigations for this report, only one of these clumps was found with four individuals, none of them in flower. Bowles (1983) lists competition from invasion of habitat by woody species, usually because of lack of fire, as the primary reason for decline in C. candidum populations. Additionally hydrological alterations may cause decline. Lythrum salicaria is also considered a threat to this species (Higman and Penskar 1988). If this species is to remain present in Kirk’s Fen immediate management should be applied to remove the Rhamnus spp. threatening to shade out this population.

Management and monitoring suggestions:

To protect this population of C. candidum, shrub removal combined with periodic early spring prescribed fire are suggested. Removing shrubs provides more light to the plants which produces larger individuals with better flowering. Flowering is common in this species in healthy populations though fruit production is typically low. Management for plant diversity should also be a goal as pollination is increased at sites with more plant diversity because of increased pollinator presence (Falb and Leopold 1993). Shrub removal in the winter will avoid trampling of plants and accidental application of herbicide. Prescribed burning has been reported to stimulate of blooming plants. An April 15th burn conducted by The Nature Conservancy at Goose Creek Grasslands in Michigan produced a large flush of blooming individuals one month later. Prior to the burn the orchids had only been located in small scattered areas (Laier 2004). Monitoring for this species should be in late May and early June when flowering aids in identification. Population trends may be difficult to determine without long-term monitoring due to the long period of time from seed to maturity and the ability of this species to enter a subterranean dormancy for a period of three to four years (Falb and Leopold 1993).

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Sanguisorba canadensis (American burnette)

Sanguisorba canadensis is a state threatened plant species with a state rank of S1, making this species more rare in the state than Cypripedium candidum. The S1 rank indicates this species is critically imperiled in the state because of extreme rarity or because of some factor making it vulnerable to extirpation in the state (MNFI 2005). Voss (1985) lists this plant as being found in wet prairies and open calcareous marshy sites. Prime threats to this species are similar to those threatening C. candidum, altered hydrology and habitat invasion by shrubs (MNFI 2005). Found only in Radrick Fen, this species appears to have a healthy population and is present throughout nearly all of the open areas. No immediate management is needed to protect this species, though maintaining open habitat through shrub removal and prescribed fire will ensure its continued presence in Radrick Fen.

Management and monitoring suggestions:

Management to protect this species should include periodic prescribed fire and brush removal through cutting and herbicide application (MNFI 2005). Monitoring should be done in August and September when this species is blooming.

Valeriana ciliata (common valerian)

Valeriana ciliata is a state threatened species with a state rank of S2, indicating that this species is imperiled in the state because of its rarity or because of some factor making it vulnerable to extirpation from the state (MNFI 2005). This species is found in alkaline fens in southern Michigan. This species is found in open areas of both fens at Matthaei Botanical Gardens. Many plants are present at each site, though numbers are considerably less at Kirk’s Fen, probably due to the lesser amount of open graminoid dominated area there. Threats are similar to the other threatened species in these fens and include invasion of habitat by Rhamnus frangula. No immediate management is necessary at Radick fen, however at Kirk’s Fen management should be implemented to prevent the complete loss of open area from R. frangula invasion. 92

Management and monitoring suggestions:

Prescribed fire and shrub removal through cutting and treating with herbicide should be used to protect the open areas of the fens that this species relies on. A study by Hannan (in press) revealed that fire had no effect on growth or flowering of this species in an Ypsilanti, Michigan fen, but no measurements on seedling recruitment were reported. Fire may not directly alter this plants growth, but will prohibit the growth of woody plants that threaten its continued existence in the fens. Monitoring of this species should be in late May through June when flowering occurs.

Sistrurus catenatus catenatus (eastern massasauga rattlesnake)

Sistrurus catenatus catenatus is a state species of special concern currently being considered for federal listing. Its state rank is S3S4, a split ranking between the S3 and S4 categories. An S3 rank is rare or uncommon in the state, whereas an S4 rank is apparently secure in the state (MNFI 2005). S. catenatus is found in a variety of wetland habitats, particularly prairie fens in southern Michigan. Some populations of this species occupy the wetlands in the spring, fall, and winter but leave these areas in the summer months to inhabit upland sites including forest openings, prairies, and old fields (Lee and Legge 2000). However, populations have been observed in Lenawee County in which none of the individuals studied moved into the surrounding uplands in the summer. Alternatively, populations in Northern Michigan appear to utilize the uplands as much, if not more than the wetlands (Lee pers. comm.). This varied use of habitat requires the protection of continuous areas of land that have both uplands and wetlands. Threats to this species include habitat loss and fragmentation of both wetland and upland habitats; draining of wetlands is particularly harmful (Lee and Legge 2000). Also listed as threats are persecution and collection by humans. Education of the public is required to stop unwanted killing or collection of this animal and efforts have been underway for some time at the Matthaei Botanical Gardens to make people aware of this unique creature. Construction of roads should be avoided in areas where this snake occurs, as vehicles increase mortality and roads fragment habitat. Roads may also act as a barrier to 93

movement as suggested by studies conducted at Indian Springs Metropark (Lee pers. comm.). This species is found in both Radrick Fen and Kirk’s Fen. During investigations of the fens for this report one observation was made in Radrick Fen and two separate observations of an individual were made in Kirk’s Fen. An individual was also seen basking in the recently burned prairie near Kirk’s Fen. A telemetry study of three individuals at Matthaei revealed that these snakes follow the pattern of using upland grassy habitats in the summer and lowland poorly drained sites in the fall. This study observed the snakes leaving the upland prairie site in the fall between September 15th and October 15th and returning to the lowlands. By November the snakes had reached their hibernation sites and did not move far from these areas (Hallock 1991). Currently the Michigan Department of Natural Resources (MDNR) and the United States Fish and Wildlife Service (USFWS) are devising a plan to partner with non-Federal property owners to provide conservation measures for this snake. Entering into this agreement, called the Candidate Conservation Agreement with Assurances (CCAA) for the eastern massasauga, will protect land owners from constraint resulting from the snake being listed for federal protection. Should this species eventually become federally listed no additional conservation measures or land, water, or resource use restrictions beyond those initially agreed upon would be required (MNDR 2004). Land owners would be responsible for monitoring, establishing research areas, and establishing an educational program. Landowners would also be required to conduct management activities according to guidelines provided in the CCAA. Unfortunately, the management guidelines recommended by the CCAA may prove to be limiting when Rhamnus spp. control through prescribed burning is needed during the growing season. However, the draft of management guidelines included in the CCAA does state that exceptions to the guidelines may be made when multiple management needs present a conflict. Once a finalized version of the CCAA is available, this agreement should be considered if the management requirements are not too restrictive. Funding for management of areas with the eastern massasauga may be available from the MDNR, the USFWS, or other government agencies (Lee pers. comm).

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Management and monitoring suggestions:

Management for S. catenatus should focus on the maintenance of open habitat. Habitats transitioning to a more closed canopy condition, as in Kirk’s Fen, provide fewer sunny spots required for thermoregulation, have less overwintering areas, and probably have less prey (Johnson et al. 2000). Ideally management activities, such as prescribed burning, should occur in November through early March when the snakes are hibernating to avoid negative effects on the population (Lee and Legge 2000). Management activities could also be conducted into late March and April if they are conducted on days when snakes are less likely to be out. These days would be characterized by windy and cloudy conditions with temperatures under 50° F and possibly light rain. Winter brush removal through cutting and herbicide application will avoid detrimental effects of the snakes. Locations of hibernacula, or hibernation boroughs, should be known if possible and protected from disturbance. Brush piles should not be burned near hibernacula. Prescribed burns in the massasauga occupied fens should take into account the following suggestions taken from Pearsall and McGowan-Stinski (2004). Detailed restrictions suggested by Pearsall and McGowan-Stinski are listed in Table 14. Locations of hibernacula, if known, should be included in the burn plan as burning is most restricted in near these areas. Back burns should be used because of their slow rate of spread and reduced intensity, allowing for snakes to move out of the way of the fire. Faster spreading head fires should be avoided especially where snakes are known to be resting. All habitat should not be burned in one year and only 35% of habitat should be burned annually. High quality habitat, with a high coverage of herbaceous plants, should be burned no more than once every three to five years. Poor quality areas, which will constitute much of Kirk’s Fen after shrubs have been removed, can be burned annually to improve habitat conditions. However, little is known about the habitat use of the Kirk’s Fen and Radrick Fen populations, or locations of hibernacula, so a conservative use of burning should be applied and monitoring should be intensive before, during, and after the burns. Monitoring the impacts of management activities both in terms of monitoring for snakes before, during, and after management activities and monitoring the long-term impacts of management on the populations is important and extremely useful. There is

95 much still to learn about the impacts of management on this species and Matthaei has a unique opportunity to contribute to the knowledge base of this subject. Monitoring for S. catenatus should take place during spring emergence (April and May) or during the basking and birthing period of mid to late summer for gravid females (late July through early September). Additionally, snakes may be observed when returning to hibernacula in the fall (mid-September through October). Surveys should be visual searches in optimal weather conditions; greater than 50% cloud cover, wind speed under 15 mph and temperatures between 50 and 80° F (Casper et al. 2000). Any time this species is observed in the fen areas, a record should be kept of the date, location, weather and any other information to add in the knowledge of the snake’s use of the areas. Observations should also be reported to the Michigan Natural Features Inventory by submitting the form found at http://web4.msue.msu.edu/mnfi/contact/Special_Species_Form.pdf or to the MDNR by submitting the form found at http://www.dnr.state.mi.us/wildlife/pubs/massasauga_obsreport.asp. This information will aid future management decisions. Management suggested in the management plans for Kirk’s Fen and Radrick Fen does not follow the recommendations made here exactly. It is my belief that burning at times deemed inappropriate for the safety of S. catenatus is sometimes justified, especially in the case of Kirk’s Fen, because of the danger of the total loss of habitat due to encroaching Rhamnus spp. Once the habitat is restored, management activities should look to follow the suggestions made here.

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Appendix B:

Specific Invasive and Problematic Species Management Information

Following are species in need of control in and around the fens at Matthaei Botanical Gardens because of their threat to the fens and the rare species present there. After each species are comments on their presence in the fen and a description of suggested control methods. Most of these species are present only in Kirk’s Fen, and unless specifically mentioned are not currently found in Radrick Fen, though should be controlled there too if found in the future. With all species, control should initially be focused on the high quality fen areas with native fen vegetation still present, and any populations found there should be immediately removed. As fen restoration efforts move ahead, populations in the restored areas of fen should receive priority with surrounding uplands to follow. Control of species by pulling or treating with herbicides followed by management with prescribed fire is likely to be successful in most cases. In the initial years of removal, follow-up treatments of pulling or herbicide application may be necessary while native fen vegetation returns and the seed bank of the invasives is exhausted. Species are listed roughly in order of greatest to least amount of threat to the fens. To avoid application of herbicide to non-target species and the introduction of herbicide into the surface water of the fen, always mix the solution in the upland areas and never set the equipment on the ground in the fen. When removing or treating vegetation the minimum number of personnel required should be used to avoid trampling of soil and rare plants, especially during growing season activities when the soil is not frozen.

Rhamnus frangula (glossy buckthorn)

Rhamnus frangula is a serious pest in fens and other damp places, especially where disturbance has occurred (Voss 1985). This species is by far the greatest threat to the fens at Matthaei Botanical Gardens as it can establish monocultures in and around fens (Spieles et al. 1999); herbaceous cover and species dominance are altered in its shade (Possessky et al. 2000). This species has a large bole and a large root system 97

allowing the uptake of large amounts of water. This uptake dries the surrounding soils creating sites that allow the establishment of more woody vegetation. An additional reason for removal is the copious amount of seeds that large individuals produce, allowing further establishment and invasion (Woods 2003). R. frangula is present in both Kirk’s Fen and Radrick Fen. In Kirk’s Fen nearly 90% of the open graminoid dominated area in 1949 is now dominated by large individuals of this species. In Radrick Fen this shrub is one of the main components of the wooded fen zone surrounding the open graminoid dominated areas. In both fens, seedlings can be found in the open areas. This species must be managed if Kirk’s Fen is to be restored and Radrick Fen is to maintain its high floristic quality. When removing these shrubs from Kirk’s Fen, all shrubs both native and non-native, should be removed to avoid the possibility that some Rhamnus frangula individuals are left behind.

Control methods:

Cutting or girdling without the application of herbicide has been shown to be ineffective in killing Rhamnus frangula (Reinartz 1997). Spring or fall burning alone is also ineffective at removing shrubs from a site, as shrubs are normally top killed but resprout quickly (Pendergrass et al. 1998, Clark and Wilson 2001, Quinlan et al. 2003). Growing season burns are more effective at controlling shrubs than dormant season burns (Bowles et al. 1996). Cutting and herbicide application combined with prescribed burning are necessary to control R. frangula in these fens. Reinartz (1997) comments that girdling is more labor intensive than cutting and treating with herbicide; additionally, stumps should be cut low to the ground (5-15 cm) as this was found to be more effective than stumps cut higher (30-60 cm). Shrub removal is possible at any time of year with cutting and herbicide treatment (Brock 2004), though some warn against applying herbicide in the spring when sap is flowing (McGowan-Stinski 2004). Ideally this treatment method will be carried out in the winter months (December to March) when the ground is frozen. This will minimize the trampling of soil and native vegetation and less damage to native vegetation by accidental herbicide application will occur (Reinartz 1997). Reinartz used a mixture of 25% glyphosphate and water to treat these shrubs; recently The Nature Conservancy has upped the amount of herbicide used to treat these 98

shrubs at Ives Rd. Fen from 13.5% active ingredient of Accord herbicide to 27% active ingredient (Woods 2003). Application of the herbicide should be with a sponge tipped PVC applicator within three minutes of cutting the stem (McGowan-Stinski 2004). Using a dye in the herbicide mix will allow applicators to see whether or not a particular shrub has been treated. Cut shrubs should be piled and burned on site during the winter months when snow is present to reduce the impact on the peat soil. Burn piles should be located in recently cleared portions of the fen with no native fen vegetation in the understory. This will avoid damaging seeds or underground portions of healthy fen vegetation. Woods estimates that between 350 to 600 man-hours are needed to clear 0.81 ha, the approximate size of Kirk’s Fen, of large Rhamnus spp. with experienced staff. Some stumps are likely to resprout, and should be retreated with herbicide when found. If herbicide use is strictly prohibited, shrubs should still be cut as native vegetation responds positively (Clark and Wilson 2001); however, these shrubs will sprout back and reclaim the area in a few years. Once adult shrubs are removed, high numbers of seedling R. frangula sprout from the seedbank, and cover recently cleared areas. These seedlings should be controlled by incineration with a propane torch one year after the initial clearing during the growing season. Failure to treat seedlings will result in the reclamation of the area by R. frangula, nullifying the efforts of adult shrub removal (Woods 2003). While burning seedlings with the torch, flame should be applied until the leaves wither and blow off from the force of the flame. Saplings up to 1.3 cm may also be killed by torching the base of the plant. One growing season treatment removes most of the seedlings and saplings. If more seedlings emerge the same season or the following season, additional treatments will be needed; however, repeat treatments are usually needed in only small patchy areas (McGowan-Stinski 2004). Torching the seedlings should continue as the preferred method until enough litter has built up at the site to begin prescribed burning for control. In cleared areas, torching of seedlings or prescribed burning during the growing season should occur annually for at least five years to deplete the seedbank of Rhamnus frangula and other invasive species. Prescribed burns during the growing season (July through August) are best for removing Rhamnus spp. seedlings, though weather conditions during this time and the large amount of smoke created by these fires cause difficulties for conducting prescribed 99

burns (McGowan-Stinski 2004). These control methods for R. frangula are effective for removing other shrubs from the fens and can be applied generally to all shrubs to be removed.

Rhamnus cathartica (common buckthorn)

Rhamnus cathartica is considered an obnoxious weed found in many habitats including swampy sites (Voss 1985) but is listed as preferring slightly drier sites than R. frangula by Herman et al. (2001). This shrub behaves similarly to R. frangula on upland sites and has the same adverse effects on native vegetation. Heneghan et al. (2004) found that decomposition of R. cathartica leaves enriched soil with nitrogen, possibly maintaining its dominance; R. frangula leaf decomposition may have similar effects on soils. Enrichment of the soil with nutrients may negatively affect the reestablishment of native vegetation and is an additional reason to remove both Rhamnus spp. from the fen sites.

Control methods:

This species should be controlled with a combination of cutting and treatment with herbicide and prescribed fire. See control methods for R. frangula for detailed information.

Lythrum salicaria (purple loosestrife)

Lythrum salicaria is a weed of damp ground, which aggressively crowds out native wetland flora (Voss 1985) and is considered a frequent invader of prairie fens (Spieles et al. 1999). This species is present in open areas of both Kirk’s Fen and Radrick Fen though luckily in low numbers as of yet. Control should be implemented immediately to prevent further spread of this species at either site as it is a direct threat to the threatened plant species present. Removal of shrub cover at Kirk’s Fen will provide this species with more suitable habitat than presently available and its population levels should be examined carefully in the season or two after shrub removal. 100

Control methods:

Hand-pulling may be enough to eliminate the small populations in both fens. Care should be taken to remove the entire root systems to avoid resprouting. Removal should be during flowering in July and August as the purple flowers make individuals easy to identify. If hand pulling is inadequate in eliminating this species an herbicide solution of Accord concentrate, 5% glyphosphate mix, or other wetland approved herbicide should be used. To apply the herbicide the inflorescences should be cut off and bagged for off- site disposal and the herbicide applied to the stem and the cut surface with a sponge- tipped PVC applicator (McGowan-Stinski 2004).

Phalaris arundinacea (reed canary grass)

Phalaris arundinacea is common in marshes, streams, , and ditches. It is unclear whether this population is native or of Eurasian decent as this species is found on both continents (Voss 1972). This species is a major invader of temperate wetlands, creating monotypic stands and displacing native vegetation (Lindig-Cisneros and Zedler 2002) and should therefore be considered a major threat to the Matthaei fens. Perry and Galatowitsch (2004) recommend that all presence of this species be removed before restoration projects begin as this species’ presence prevents the establishment of sedge meadow vegetation in the Midwest. Once established the species is difficult to control without negatively affecting other fen vegetation. Difficulty in identifying this species may also add to the difficulty of its control (Woods 2003). In Kirk’s Fen small patches of Phalaris arundinacea are present in several locations in the Rhamnus spp. dominated areas. Areas surrounding Kirk’s Fen should also be cleared of this pest before work begins to avoid future reestablishment of the fen. If a healthy seed bank is not present, elimination of P. arundinacea may only occur with supplemental seeding of native species (TNC 2005).

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Control methods:

Hand removal by pulling or digging is ineffective as the entire root system is seldom removed resulting in resprouting. Removal should be during the growing season and McGowan-Stinski (2004) states that the most effective and efficient way to remove small patches is to sheaf the clump with twine near the base, cut off plant material above the twine, then treat the stems and cut portions with an herbicide solution of Accord concentrate, 5% glyphosphate mix, or other wetland approved herbicide with a PVC sponge applicator or by spraying with a backpack sprayer. Care should be taken not to apply herbicide to native fen species. If cut portions of the grass contain seed, they should be bagged and removed from the site to prevent spread of the seed.

Phragmites australis (reed)

Phragmites australis is common in wet areas including tamarack bogs and spreads mainly through vegetative reproduction, forming large colonies by rhizomes as long as 13.1 m (Voss 1972). This species is present only in the southwest portion of Radrick Fen. A study by Gladwin (2003) conducted in Radrick Fen revealed that native plant biomass was reduced in its presence, and also that plants typical of high quality areas of the fen were less frequent in invaded areas. This population has been expanding in recent years (B. Klatt pers. comm.) and should be controlled by management.

Control methods:

This species is difficult to remove by hand because of its extensive root system. Cutting of the stems in late July when the food reserves are still in the above-ground portion of the plant may be effective at reducing the population’s vigor if repeated annually over many years (TNC 2005); however this method is time and labor intensive. Quicker and more effective results may be attained with herbicide use. An herbicide solution of Accord concentrate, 5% glyphosphate mix, or other wetland approved herbicide is applied with a PVC sponge applicator or a modified saline solution bottle to the cut surface and inside the stem (McGowan-Stinski 2004). A fen in Massachusetts has 102

had success with this saline solution bottle method. After the stems are cut at chest height, the squirt bottles are used to fill the stems with herbicide. This method is also effective at avoiding herbicide contact with non-target species. With any removal method, cut portions of the stems should be removed from the site or burned to prevent the spread of seed, or the sprouting and rooting of the remains (TNC 2005).

Alliaria petiolata (garlic mustard)

Alliaria petiolata is a serious threat to many ecosystems in the Midwest, including fens. This species spreads quickly through seed production and may inhibit other plant species through allelopathic properties (Woods 2003). Once established, eradication is difficult, so prevention of initial establishment is key (TNC 2005). It is present in small numbers on the edges of Kirk’s Fen and seems to be spreading into the fen from nearby sources especially along Kirk’s Brook. Areas should be managed for at least 2-5 years to eliminate the seed bank of this species (TNC 2005). However, deer may continuously bring new seed into the fen requiring yearly management of this species. A combination of hand-pulling and prescribed fire will be beneficial in controlling Alliaria petiolata.

Control Methods:

Hand-pulling is the preferred control method for this species, especially when populations are small and easy to control as in Kirk’s Fen. Removal should be during flowering, usually in late April to May, as the species is easily identified during this time. Care should be taken to remove the entire plant, roots included. Once pulled the plants should be bagged and removed from site to prevent further spreading of the seeds. Prescribed fire has had mixed results in controlling Alliaria, reducing increasing, or causing no change in the populations present. If fire is to be used it should be used in at least two consecutive years as burning once has actually increased the abundance of this species (TNC 2005). Herbicide use to control this plant is effective, but detrimental to surrounding native plants so should be avoided if possible.

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Cirsium arvense (Canadian-thistle)

Cirsium arvense was noted as a pest in Michigan as early as 1876. It is common in many ecosystem types including swampy ground and its deep root system makes it difficult to eradicate (Voss 1996). As with other aggressive invaders it can decrease species diversity and displace native vegetation (TNC 2005). It is common in the fen and will likely establish throughout the fen after it has been cleared of shrubs and burned (Reznicek pers. comm.). Woods (2003) notes that Cirsium arvense establishes in dense populations where brush piles recently burned. Woods also predicts that as native fen vegetation spreads and water levels are returned to a fen through restoration this species will become less of a problem. If individuals of this plant become established in the high quality remaining areas of Kirk’s Fen or begin to compete with threatened species they should be removed immediately.

Control methods:

TNC (2005) suggests enhancing the growth of native species with spring burns then treating with herbicide while in bud or before seed set in June. This may be a good strategy in the restored areas of the fen; however, herbicide use should be avoided in the remaining high quality areas and plants in these areas should be pulled by hand. Plants without seeds may be left on site, but plants with seed should be removed. Areas should be monitored at least two seasons after treatment to determine the effectiveness of removal as declines are often reported the first year followed by a return to initial levels (TNC 2005).

Cirsium vulgare (bull-thistle)

Cirsium vulgare is a common weed of disturbed areas and is known to spread after fire or other disturbances and has the ability to invade natural communities near disturbed habitats (Voss 1996). It is present in many areas of Kirk’s Fen though not in high numbers. Similar to C. arvense it is likely to be less of a problem as restoration proceeds, and native cover increases on the site. 104

Control methods:

Control methods are similar to C. arvense. Hand removal is the preferred method of this species in the remaining high quality areas of Kirk’s Fen. Prescribed fire will also contribute to the control of this species by encouraging growth of native vegetation. If hand removal proves inadequate, herbicide application may be necessary.

Typha latifolia (broad-leaved cat-tail)

Typha latifolia is found in wet habitats and in a single season one seed may produce a rhizome system 3.3 m in diameter with 100 shoots and as many buds (Voss 1972). In Kirk’s Fen there are only a few small plants located in the remaining open portions. The removal of shrubs in this fen will provide T. latifolia with an increased amount of suitable habitat; therefore, control should occur before these individuals are given the opportunity to spread.

Control methods:

While the populations are so small, control may be achieved by hand-pulling the entire plant including all rhizomes present to avoid resprouting. If hand pulling is inadequate in eliminating this species an herbicide solution of Accord concentrate, 5% glyphosphate mix, or other wetland approved herbicide should be used. To apply the herbicide the stems should be cut should be cut and the herbicide applied to the stem and the cut surface with a sponge-tipped PVC applicator (McGowan-Stinski 2004). Remains of the plant can be left on site or burned in the brush pile.

Hesperis matronalis (dame’s rocket)

Hesperis matronalis is a non-native invasive plant occurring in many habitats including damp woods (Voss 1985). It is somewhat common in Kirk’s Fen. It spreads

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through seed and is likely to spread in the areas in and around Kirk’s Fen. It poses many of the same threats as Alliaria petiolata and should be treated similarly.

Control methods:

Plants should be controlled through hand pulling, being sure to remove all underground portions, and removed from the site to prevent spread of seed (Woods 2003). Control should be during late April and May when flowering occurs to help in the identification of populations. Several years of control may be needed to exhaust the seedbank.

Lonicera maackii (Amur honeysuckle) and Lonicera tatarica (smooth Tartarian honeysuckle)

These species are found in many habitat types and are becoming pests throughout the Midwest, reducing species richness and cover in herbaceous communities and tree regeneration in forests (TNC 2005). Voss (1996) states that L. maackii is distributed by birds; this is likely the true for L. tatarica as well. These species are common throughout Kirk’s Fen and should be removed with all other shrubs in the initial stages of restoration.

Control methods:

Removal of these species requires the use of herbicides. Removal should be accomplished by cutting and treating the stumps with herbicide. A mix of 20% glyphosphate and an oil based dilutent was found to be effective at killing these shrubs at any time of year (Brock 2004). Work should be in the winter to avoid trampling soil and vegetation, and harming native vegetation with herbicide. Plants can then be disposed of by burning in brush piles or removed from site to prevent the spreading of seed. Hand removal by cutting or pulling may be effective if done annually over a period of three to five years; however any portion of the roots left behind may sprout. Prescribed fire is also effective at top-killing the shrubs, but Lonicera spp. resprout readily and fire alone is unlikely to rid a site of these species (TNC 2005). 106

Rosa multiflora (multiflora rose)

Rosa multiflora is an aggressive weed that occurs in many places including disturbed woods (Voss 1996). This species is present in the areas dominated by Rhamnus spp. in Kirk’s Fen. Initially no special effort should be made to target only this species, as all shrubs are suggested to be removed from the site by cutting and treating of the stumps with herbicide.

Control methods:

Removal is similar to other woody shrubs and cutting and treatment with herbicide should be conducted in the winter with other shrub removal efforts to avoid trampling soil and vegetation, and harming native vegetation with herbicide. Plants can be disposed of by burning on-site in brush piles.

Berberis thunbergii (Japanese barberry)

Berberis thunbergii is a common invader of woodlands in Ann Arbor and can become naturalized in disturbed forests (Barnes and Wagner 2002). It can establish in numbers quickly through rhizomes, seeding, and is dispersed by birds (Woods 2003). It is not currently common in Kirk’s Fen. Initially no special effort should be made to target only this species, as all shrubs are suggested to be removed from the site by cutting and treating of the stumps with herbicide.

Control methods:

Shrubs should be cut and the stumps treated with an herbicide solution; at Ives Rd. Fen a 3:1 rinsate:herbicide (53% active Accord herbicide) solution was used (Woods 2003). Hand removal is also a possibility, however this causes soil disturbance. Plants can then be disposed of by burning in brush piles or removed from site to prevent the

107 spreading of seed. Removal should be in the winter to avoid trampling soil and vegetation, and harming native vegetation with herbicide.

Non-native species present but not a threat currently Agrostis gigantea- redtop Arctium minus- common burdock Barbarea vulgaris- yellow rocket Cardamine impatiens- bitter cress Cynoglossum officinale- hound’s-tongue Malus pumila- apple (Radrick) Poa pratensis- Kentucky bluegrass (Radrick) Myosotis scorpioides- forget-me-not Prunella vulgaris- lawn prunella, self-heal; heal-all Solanum dulcamara- bittersweet nightshade; bittersweet Taraxacum officinale- common dandelion

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Tables

Table 1. Species typical of prairie fen vegetation zones. Species marked with an * are considered indicator species for Michigan (Spieles et al. 1999).

Inundated flat Cladium mariscoides Eleocharis. rostellata Scirpus acutus Eleocharis elliptica Juncus brachycephalus Scirpus americanus

Sedge meadow Andropogon gerardii Carex sterilis Potentilla fruiticosa * Andropogon scoparius Carex stricta Pycnanthemum virginianum * Aster spp. Cornus spp. Rudbeckia hirta Betula pumila Eupatorium maculatum Sorghastrum nutans * Bromus ciliatus Eupatorium perfoliatum Solidago ohioensis * Calamagrostis Lysimachia qaudriflora Solidago riddellii * canadensis Carex aquatilis Muhlenbergia glomerata Thelypteris palustris

Calcareous seep Carex flava Parnassia glauca * Triglochin maritimum Drosera rotundifolia Rhynchospora alba Utricularia intermedia Lobelia kalmii Sarracenia purpurea

Wooded fen Acer rubrum Larix laricina * Spiraea alba Cornus foemina Physocarpus opulifolius Ulmus americana Cornus stolonifera Salix candida Toxicodendron vernix *

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Table 2. Kirk’s Fen Floristic Quality Analysis data.

FLORISTIC QUALITY DATA Native 95 84.10% Adventive 18 15.9% NATIVE SPECIES 95 Tree 11 9.70% Tree 1 0.9% Total Species 113 Shrub 11 9.70% Shrub 4 3.5% NATIVE MEAN C 4.7 Woody Vine 4 3.50% Woody Vine 0 0.0% Herbaceous Herbaceous W/Adventives 4 Vine 0 0.00% Vine 0 0.0% Perennial Perennial NATIVE FQI 46.2 Forb 47 41.60% Forb 6 5.3% Biennial W/Adventives 42.3 Forb 1 0.90% Biennial Forb 5 4.4% NATIVE Annual MEAN W -1.8 Forb 4 3.50% Annual Forb 1 0.9% Perennial Perennial W/Adventives -1.3 Grass 7 6.20% Grass 1 0.9% Fac. Annual Annual AVG: Wetland (-) Grass 0 0.00% Grass 0 0.0% Perennial Perennial Sedge 8 7.10% Sedge 0 0.0% Annual Annual Sedge 0 0.00% Sedge 0 0.0% Fern 2 1.80% Fern 0 0.0%

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Table 3. Species list of vegetation in Kirk’s Fen and associated FQA information for each plant. Scientific names in all capital letters are adventive species.

SCIENTIFIC NAME C W WETNESS PHYSIOGNOMY COMMON NAME Acer negundo 0 -2 FACW- Nt Tree BOX ELDER Acer saccharum 5 3 FACU Nt Tree SUGAR MAPLE SLENDER WHEAT Agropyron trachycaulum 8 0 FAC Nt P-Grass GRASS AGROSTIS GIGANTEA 0 0 FAC Ad P-Grass REDTOP ALLIARIA PETIOLATA 0 0 FAC Ad B-Forb GARLIC MUSTARD Allium cernuum 5 5 UPL Nt P-Forb NODDING WILD ONION Amphicarpaea bracteata 5 0 FAC Nt A-Forb HOG PEANUT Andropogon gerardii 5 1 FAC- Nt P-Grass BIG BLUESTEM ARCTIUM MINUS 0 5 UPL Ad B-Forb COMMON BURDOCK Arisaema triphyllum 5 -2 FACW- Nt P-Forb JACK IN THE PULPIT Asclepias incarnata 6 -5 OBL Nt P-Forb SWAMP MILKWEED Aster laevis 5 5 UPL Nt P-Forb SMOOTH ASTER SIDE FLOWERING Aster lateriflorus 2 -2 FACW- Nt P-Forb ASTER Aster pilosus 1 2 FACU+ Nt P-Forb HAIRY ASTER Aster puniceus 5 -5 OBL Nt P-Forb SWAMP ASTER BARBAREA VULGARIS 0 0 FAC Ad B-Forb YELLOW ROCKET Bromus ciliatus 6 -3 FACW Nt P-Grass FRINGED BROME Calamagrostis canadensis 3 -5 OBL Nt P-Grass BLUE JOINT GRASS CARDAMINE IMPATIENS 0 5 UPL Ad A-Forb BITTER CRESS Carex blanda 1 0 FAC Nt P-Sedge SEDGE Carex buxbaumii 10 -5 OBL Nt P-Sedge SEDGE Carex leptalea 5 -5 OBL Nt P-Sedge SEDGE Carex sterilis 10 -5 OBL Nt P-Sedge SEDGE Carex stricta 4 -5 OBL Nt P-Sedge SEDGE Carex tetanica 9 -3 FACW Nt P-Sedge SEDGE Carpinus caroliniana 6 0 FAC Nt Tree BLUE BEECH CIRSIUM ARVENSE 0 3 FACU Ad P-Forb CANADIAN THISTLE Cirsium muticum 6 -5 OBL Nt B-Forb SWAMP THISTLE CIRSIUM VULGARE 0 4 FACU- Ad B-Forb BULL THISTLE Clematis virginiana 4 0 FAC Nt W-Vine VIRGIN'S BOWER ALTERNATE LEAVED Cornus alternifolia 5 5 UPL Nt Tree DOGWOOD Cornus amomum 2 -4 FACW+ Nt Shrub SILKY DOGWOOD Cornus stolonifera 2 -3 FACW Nt Shrub RED OSIER DOGWOOD Corylus americana 5 4 FACU- Nt Shrub HAZELNUT CYNOGLOSSUM OFFICINALE 0 5 UPL Ad B-Forb HOUND'S TONGUE Cypripedium candidum 10 -5 OBL Nt P-Forb WHITE LADY'S SLIPPER Eleocharis rostellata 10 -5 OBL Nt P-Sedge SPIKE RUSH CINNAMON WILLOW Epilobium coloratum 3 -5 OBL Nt P-Forb HERB Equisetum arvense 0 0 FAC Nt Fern Ally COMMON HORSETAIL Erechtites hieracifolia 2 3 FACU Nt A-Forb FIREWEED Eupatorium maculatum 4 -5 OBL Nt P-Forb JOE PYE WEED 111

Eupatorium perfoliatum 4 -4 FACW+ Nt P-Forb COMMON BONESET Eupatorium purpureum 5 0 FAC Nt P-Forb PURPLE JOE PYE WEED GRASS LEAVED Euthamia graminifolia 3 -2 FACW- Nt P-Forb GOLDENROD Fraxinus americana 5 3 FACU Nt Tree WHITE ASH Fraxinus nigra 6 -4 FACW+ Nt Tree BLACK ASH Galium boreale 3 0 FAC Nt P-Forb NORTHERN BEDSTRAW Galium triflorum 4 2 FACU+ Nt P-Forb FRAGRANT BEDSTRAW Geum canadense 1 0 FAC Nt P-Forb WHITE AVENS Hackelia virginiana 1 1 FAC- Nt P-Forb BEGGAR'S LICE HESPERIS MATRONALIS 0 5 UPL Ad P-Forb DAME'S ROCKET Hierochloe odorata 9 -3 FACW Nt P-Grass SWEET GRASS Hypoxis hirsuta 10 0 FAC Nt P-Forb STAR GRASS Juncus brachycephalus 7 -5 OBL Nt P-Forb RUSH Juniperus virginiana 3 3 FACU Nt Tree RED CEDAR Larix laricina 5 -3 FACW Nt Tree TAMARACK Lobelia siphilitica 4 -4 FACW+ Nt P-Forb GREAT BLUE LOBELIA LONICERA MAACKII 0 5 UPL Ad Shrub AMUR HONEYSUCKLE SMOOTH TARTARIAN LONICERA TATARICA 0 3 FACU Ad Shrub HONEYSUCKLE COMMON WATER Lycopus americanus 2 -5 OBL Nt P-Forb HOREHOUND WHORLED Lysimachia quadriflora 10 -5 OBL Nt P-Forb LOOSESTRIFE LYTHRUM SALICARIA 0 -5 OBL Ad P-Forb PURPLE LOOSESTRIFE Mentha arvensis 3 -3 FACW Nt P-Forb WILD MINT Muhlenbergia glomerata 10 -4 FACW+ Nt P-Grass MARSH WILD TIMOTHY MYOSOTIS SCORPIOIDES 0 -5 OBL Ad P-Forb FORGET ME NOT NORTHERN WOOD Oxalis acetosella 7 3 FACU Nt P-Forb SORREL Oxypolis rigidior 6 -5 OBL Nt P-Forb COWBANE Parnassia glauca 8 -5 OBL Nt P-Forb GRASS OF PARNASSUS Parthenocissus quinquefolia 5 1 FAC- Nt W-Vine VIRGINIA CREEPER Phalaris arundinacea 0 -4 FACW+ Nt P-Grass REED CANARY GRASS Phryma leptostachya 4 5 UPL Nt P-Forb LOPSEED Physocarpus opulifolius 4 -2 FACW- Nt Shrub NINEBARK Picea glauca 3 3 FACU Nt Tree WHITE SPRUCE Pilea fontana 5 -3 FACW Nt A-Forb BOG CLEARWEED Polygonum hydropiperoides 5 -5 OBL Nt P-Forb WATER PEPPER Potentilla fruticosa 10 -3 FACW Nt Shrub SHRUBBY CINQUEFOIL PRUNELLA VULGARIS 0 0 FAC Nt P-Forb LAWN PRUNELLA Prunus virginiana 2 1 FAC- Nt Shrub CHOKE CHERRY Pycnanthemum COMMON MOUNTAIN virginianum 5 -4 FACW+ Nt P-Forb MINT Ranunculus recurvatus 5 -3 FACW Nt A-Forb HOOKED CROWFOOT ALDER LEAVED Rhamnus alnifolia 8 -5 OBL Nt Shrub BUCKTHORN RHAMNUS CATHARTICA 0 3 FACU Ad Tree COMMON BUCKTHORN RHAMNUS FRANGULA 0 -1 FAC+ Ad Shrub GLOSSY BUCKTHORN

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PRICKLY or WILD Ribes cynosbati 4 5 UPL Nt Shrub GOOSEBERRY ROSA MULTIFLORA 0 3 FACU Ad Shrub MULTIFLORA ROSE Rubus pubescens 4 -4 FACW+ Nt P-Forb DWARF RASPBERRY Rubus strigosus 2 -2 FACW- Nt Shrub WILD RED RASPBERRY Rudbeckia hirta 1 3 FACU Nt P-Forb BLACK EYED SUSAN Salix bebbiana 1 -4 FACW+ Nt Shrub BEBB'S WILLOW Salix candida 9 -5 OBL Nt Shrub HOARY WILLOW Schoenoplectus acutus 5 -5 OBL Nt P-Sedge HARDSTEM BULRUSH Senecio aureus 5 -3 FACW Nt P-Forb GOLDEN RAGWORT Smilacina racemosa 5 3 FACU Nt P-Forb FALSE SPIKENARD BITTERSWEET SOLANUM DULCAMARA 0 0 FAC Ad P-Forb NIGHTSHADE Solidago gigantea 3 -3 FACW Nt P-Forb LATE GOLDENROD Solidago ohioensis 8 -5 OBL Nt P-Forb GOLDENROD Solidago patula 6 -5 OBL Nt P-Forb SWAMP GOLDENROD Solidago riddellii 6 -5 OBL Nt P-Forb RIDDELL'S GOLDENROD Solidago rugosa 3 -1 FAC+ Nt P-Forb ROUGH GOLDENROD Solidago uliginosa 4 -5 OBL Nt P-Forb BOG GOLDENROD Symplocarpus foetidus 6 -5 OBL Nt P-Forb SKUNK CABBAGE TARAXACUM OFFICINALE 0 3 FACU Ad P-Forb COMMON DANDELION Thalictrum dasycarpum 3 -2 FACW- Nt P-Forb PURPLE MEADOW RUE Thelypteris palustris 2 -4 FACW+ Nt Fern MARSH FERN Tilia americana 5 3 FACU Nt Tree BASSWOOD Toxicodendron radicans 2 -1 FAC+ Nt W-Vine POISON IVY BROAD LEAVED Typha latifolia 1 -5 OBL Nt P-Forb CATTAIL Ulmus americana 1 -2 FACW- Nt Tree AMERICAN ELM Valeriana ciliata 10 -5 OBL Nt P-Forb COMMON VALERIAN Valeriana uliginosa 10 -4 FACW+ Nt P-Forb BOG VALERIAN Verbena urticifolia 4 -1 FAC+ Nt P-Forb WHITE VERVAIN Vitis riparia 3 -2 FACW- Nt W-Vine RIVERBANK GRAPE Zizia aurea 6 -1 FAC+ Nt P-Forb GOLDENALEXANDERS

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Table 4. Radrick Fen Floristic Quality Analysis data.

FLORISTIC QUALITY DATA Native 133 97.10% Adventive 4 2.90% NATIVE SPECIES 133 Tree 11 8.00% Tree 1 0.70%

Total Species 137 Shrub 19 13.90% Shrub 1 0.70% NATIVE MEAN C 5.3 Woody Vine 2 1.50% Woody Vine 0 0.00% Herbaceous Herbaceous W/Adventives 5.2 Vine 0 0.00% Vine 0 0.00%

NATIVE FQI 61.4 Perennial Forb 69 50.40% Perennial Forb 1 0.70%

W/Adventives 60.5 Biennial Forb 1 0.70% Biennial Forb 0 0.00% NATIVE MEAN W -2.9 Annual Forb 3 2.20% Annual Forb 0 0.00% Perennial Perennial W/Adventives -2.8 Grass 8 5.80% Grass 1 0.70% Fac. AVG Wetland Annual Grass 0 0.00% Annual Grass 0 0.00% Perennial Perennial Sedge 16 11.70% Sedge 0 0.00% Annual Sedge 0 0.00% Annual Sedge 0 0.00% Fern 4 2.90% Fern 0 0.00%

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Table 5. Species list of vegetation in Radrick Fen and associated FQA information for each plant. Scientific names in all capital letters are adventive species.

SCIENTIFIC NAME C W WETNESS PHYSIOGNOMY COMMON NAME Acer rubrum 1 0 FAC Nt Tree RED MAPLE Acer saccharum 5 3 FACU Nt Tree SUGAR MAPLE Amelanchier laevis 4 5 UPL Nt Tree SMOOTH SHADBUSH Andropogon gerardii 5 1 FAC- Nt P-Grass BIG BLUESTEM Apios americana 3 -3 FACW Nt P-Forb GROUNDNUT Apocynum cannabinum 3 0 FAC Nt P-Forb INDIAN HEMP Asclepias incarnata 6 -5 OBL Nt P-Forb SWAMP MILKWEED Aster laevis 5 5 UPL Nt P-Forb SMOOTH ASTER Aster lanceolatus 2 -3 FACW Nt P-Forb EASTERN LINED ASTER Aster lateriflorus 2 -2 FACW- Nt P-Forb SIDE FLOWERING ASTER Aster novae-angliae 3 -3 FACW Nt P-Forb NEW ENGLAND ASTER Aster puniceus 5 -5 OBL Nt P-Forb SWAMP ASTER Aster umbellatus 5 -3 FACW Nt P-Forb TALL FLAT TOP WHITE ASTER Betula pumila 8 -5 OBL Nt Shrub BOG BIRCH Bromus ciliatus 6 -3 FACW Nt P-Grass FRINGED BROME Calamagrostis canadensis 3 -5 OBL Nt P-Grass BLUE JOINT GRASS Calopogon tuberosus 9 -5 OBL Nt P-Forb GRASS PINK Caltha palustris 6 -5 OBL Nt P-Forb MARSH MARIGOLD Campanula aparinoides 7 -5 OBL Nt P-Forb MARSH BELLFLOWER Cardamine bulbosa 4 -5 OBL Nt P-Forb SPRING CRESS Carex granularis 2 -4 FACW+ Nt P-Sedge SEDGE Carex hystericina 2 -5 OBL Nt P-Sedge SEDGE Carex interior 3 -5 OBL Nt P-Sedge SEDGE Carex lacustris 6 -5 OBL Nt P-Sedge SEDGE Carex leptalea 5 -5 OBL Nt P-Sedge SEDGE Carex pellita 2 -5 OBL Nt P-Sedge SEDGE Carex prairea 10 -4 FACW+ Nt P-Sedge SEDGE Carex sterilis 10 -5 OBL Nt P-Sedge SEDGE Carex stricta 4 -5 OBL Nt P-Sedge SEDGE Carex tetanica 9 -3 FACW Nt P-Sedge SEDGE Carpinus caroliniana 6 0 FAC Nt Tree BLUE BEECH Chelone glabra 7 -5 OBL Nt P-Forb TURTLEHEAD Cicuta bulbifera 5 -5 OBL Nt P-Forb WATER HEMLOCK Cirsium muticum 6 -5 OBL Nt B-Forb SWAMP THISTLE Clematis virginiana 4 0 FAC Nt W-Vine VIRGIN'S BOWER Cornus alternifolia 5 5 UPL Nt Tree ALTERNATE LEAVED DOGWOOD Cornus foemina 1 -2 FACW- Nt Shrub GRAY DOGWOOD Cornus stolonifera 2 -3 FACW Nt Shrub RED OSIER DOGWOOD Corylus americana 5 4 FACU- Nt Shrub HAZELNUT Cypripedium calceolus var. parviflorum 7 -1 FAC+ Nt P-Forb SMALL YELLOW LADY'S SLIPPER SHOWY or QUEEN'S LADY Cypripedium reginae 9 -4 FACW+ Nt P-Forb SLIPPER Drosera rotundifolia 6 -5 OBL Nt P-Forb ROUND LEAVED SUNDEW Dryopteris cristata 6 -5 OBL Nt Fern CRESTED SHIELD FERN

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Eleocharis elliptica 6 -3 FACW Nt P-Sedge GOLDEN SEEDED SPIKE RUSH Epilobium ciliatum 3 3 FACU Nt P-Forb WILLOW HERB Epilobium leptophyllum 6 -5 OBL Nt P-Forb FEN WILLOW HERB Eriophorum viridi- GREEN KEELED COTTON carinatum 8 -5 OBL Nt P-Sedge GRASS Eupatorium maculatum 4 -5 OBL Nt P-Forb JOE PYE WEED Eupatorium perfoliatum 4 -4 FACW+ Nt P-Forb COMMON BONESET Fragaria virginiana 2 1 FAC- Nt P-Forb WILD STRAWBERRY Fraxinus nigra 6 -4 FACW+ Nt Tree BLACK ASH Galium asprellum 5 -5 OBL Nt P-Forb ROUGH BEDSTRAW Galium boreale 3 0 FAC Nt P-Forb NORTHERN BEDSTRAW Galium labradoricum 8 -5 OBL Nt P-Forb BOG BEDSTRAW Gentianopsis procera 8 -5 OBL Nt A-Forb SMALL FRINGED GENTIAN Geranium maculatum 4 3 FACU Nt P-Forb WILD GERANIUM Geum rivale 7 -5 OBL Nt P-Forb PURPLE AVENS Glyceria striata 4 -5 OBL Nt P-Grass FOWL MANNA GRASS Helianthus giganteus 5 -3 FACW Nt P-Forb TALL SUNFLOWER Hypoxis hirsute 10 0 FAC Nt P-Forb STAR GRASS Impatiens capensis 2 -3 FACW Nt A-Forb SPOTTED TOUCH ME NOT Iris virginica 5 -5 OBL Nt P-Forb SOUTHERN BLUE FLAG Juncus brachycephalus 7 -5 OBL Nt P-Forb RUSH Juniperus virginiana 3 3 FACU Nt Tree RED CEDAR Lathyrus palustris 7 -3 FACW Nt P-Forb MARSH PEA Lemna minor 5 -5 OBL Nt A-Forb SMALL DUCKWEED Liatris spicata 8 0 FAC Nt P-Forb MARSH BLAZING STAR Lobelia kalmii 10 -5 OBL Nt P-Forb BOG LOBELIA Lysimachia quadriflora 10 -5 OBL Nt P-Forb WHORLED LOOSESTRIFE Lysimachia thyrsiflora 6 -5 OBL Nt P-Forb TUFTED LOOSESTRIFE LYTHRUM SALICARIA 0 -5 OBL Ad P-Forb PURPLE LOOSESTRIFE MALUS PUMILA 0 5 UPL Ad Tree APPLE Mentha arvensis 3 -3 FACW Nt P-Forb WILD MINT Muhlenbergia glomerata 10 -4 FACW+ Nt P-Grass MARSH WILD TIMOTHY Muhlenbergia mexicana 3 -3 FACW Nt P-Grass LEAFY SATIN GRASS Onoclea sensibilis 2 -3 FACW Nt Fern SENSITIVE FERN Oxypolis rigidior 6 -5 OBL Nt P-Forb COWBANE Parnassia glauca 8 -5 OBL Nt P-Forb GRASS OF PARNASSUS Phragmites australis 0 -4 FACW+ Nt P-Grass REED Physocarpus opulifolius 4 -2 FACW- Nt Shrub NINEBARK POA PRATENSIS 0 1 FAC- Ad P-Grass KENTUCKY BLUEGRASS Polygala paucifolia 7 3 FACU Nt P-Forb GAY WINGS Populus tremuloides 1 0 FAC Nt Tree QUAKING ASPEN Potentilla fruticosa 10 -3 FACW Nt Shrub SHRUBBY CINQUEFOIL Potentilla palustris 7 -5 OBL Nt P-Forb MARSH CINQUEFOIL Pycnanthemum virginianum 5 -4 FACW+ Nt P-Forb COMMON MOUNTAIN MINT

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Quercus macrocarpa 5 1 FAC- Nt Tree BUR OAK Quercus rubra 5 3 FACU Nt Tree RED OAK Ranunculus hispidus 5 0 FAC Nt P-Forb SWAMP BUTTERCUP Rhamnus alnifolia 8 -5 OBL Nt Shrub ALDER LEAVED BUCKTHORN RHAMNUS FRANGULA 0 -1 FAC+ Ad Shrub GLOSSY BUCKTHORN Rhynchospora alba 6 -5 OBL Nt P-Sedge BEAK RUSH Rhynchospora capillacea 10 -5 OBL Nt P-Sedge BEAK RUSH Ribes americanum 6 -3 FACW Nt Shrub WILD BLACK CURRANT Ribes hirtellum 6 -3 FACW Nt GOOSEBERRY Rubus pubescens 4 -4 FACW+ Nt P-Forb DWARF RASPBERRY Rubus strigosus 2 -2 FACW- Nt Shrub WILD RED RASPBERRY Rudbeckia hirta 1 3 FACU Nt P-Forb BLACK EYED SUSAN Salix bebbiana 1 -4 FACW+ Nt Shrub BEBB'S WILLOW Salix candida 9 -5 OBL Nt Shrub HOARY WILLOW Salix discolor 1 -3 FACW Nt Shrub PUSSY WILLOW Salix eriocephala 2 -3 FACW Nt Shrub WILLOW Salix petiolaris 1 -4 FACW+ Nt Shrub SLENDER WILLOW Salix serissima 8 -5 OBL Nt Shrub AUTUMN WILLOW Sanguisorba canadensis 10 -4 FACW+ Nt P-Forb AMERICAN BURNET Sarracenia purpurea 10 -5 OBL Nt P-Forb PITCHER PLANT Schoenoplectus acutus 5 -5 OBL Nt P-Sedge HARDSTEM BULRUSH Scirpus atrovirens 3 -5 OBL Nt P-Sedge BULRUSH Selaginella eclipes 5 -4 FACW+ Nt Fern Ally SELAGINELLA Senecio aureus 5 -3 FACW Nt P-Forb GOLDEN RAGWORT Smilacina stellata 5 1 FAC- Nt P-Forb STARRY FALSE SOLOMON SEAL Solidago altissima 1 3 FACU Nt P-Forb TALL GOLDENROD Solidago gigantea 3 -3 FACW Nt P-Forb LATE GOLDENROD Solidago ohioensis 8 -5 OBL Nt P-Forb OHIO GOLDENROD Solidago patula 6 -5 OBL Nt P-Forb SWAMP GOLDENROD Solidago riddellii 6 -5 OBL Nt P-Forb RIDDELL'S GOLDENROD Solidago uliginosa 4 -5 OBL Nt P-Forb BOG GOLDENROD Sorghastrum nutans 6 2 FACU+ Nt P-Grass INDIAN GRASS Sparganium eurycarpum 5 -5 OBL Nt P-Forb COMMON BUR REED Spiraea alba 4 -4 FACW+ Nt Shrub MEADOWSWEET Symplocarpus foetidus 6 -5 OBL Nt P-Forb SKUNK CABBAGE Thalictrum dasycarpum 3 -2 FACW- Nt P-Forb PURPLE MEADOW RUE Thelypteris palustris 2 -4 FACW+ Nt Fern MARSH FERN Tilia americana 5 3 FACU Nt Tree BASSWOOD Tofieldia glutinosa 10 -5 OBL Nt P-Forb FALSE ASPHODEL Toxicodendron radicans 2 -1 FAC+ Nt W-Vine POISON IVY Toxicodendron vernix 6 -5 OBL Nt Shrub POISON SUMAC Triglochin maritimum 8 -5 OBL Nt P-Forb COMMON BOG ARROW GRASS Triglochin palustris 8 -5 OBL Nt P-Forb SLENDER BOG ARROW GRASS

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Typha latifolia 1 -5 OBL Nt P-Forb BROAD LEAVED CATTAIL Utricularia intermedia 10 -5 OBL Nt P-Forb FLAT LEAVED BLADDERWORT Utricularia minor 10 -5 OBL Nt P-Forb SMALL BLADDERWORT Valeriana ciliata 10 -5 OBL Nt P-Forb COMMON VALERIAN Valeriana uliginosa 10 -4 FACW+ Nt P-Forb BOG VALERIAN Viburnum lentago 4 -1 FAC+ Nt Shrub NANNYBERRY Viola cucullata 5 -5 OBL Nt P-Forb MARSH VIOLET Zizia aurea 6 -1 FAC+ Nt P-Forb GOLDEN ALEXANDERS

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Table 6a. Kirk’s Fen soil and water table transect parallel to slope. Sampling units listed west to east.

Sampling unit Water table (cm) Rebar depth (m) Soil description to one meter 1 20 cm below 1.2 m mix (sapric-hemic)

mix 2 10 cm below 1.5 m (sapric-hemic, hemic fibric below 0.6 m) 3 Surface > 1.7 m mix (hemic-fibric) 4 15 cm below > 1.7 m mix (sapric-hemic) 5 18 cm below > 1.7 m mix (sapric-hemic) 6 surface > 1.7 m mix (hemic-fibric) 7 surface 1.5 m mix (hemic-fibric)

Table 6b. Kirk’s Fen eastern soil and water table transect perpendicular to slope. Sampling units listed north to south.

Sampling unit Water table (cm) Rebar depth (m) Soil description to one meter 1 23 cm below > 1.7 m mix (sapric-hemic) 2 23 cm below > 1.7 m mix (sapric-hemic) 3 20 cm below > 1.7 m mix (sapric-hemic) 4 13 cm below > 1.7 m mix (hemic-fibric) 5 15 cm below > 1.7 m mix (hemic-fibric) 6 surface > 1.7 m mix (hemic-fibric) mix 7 13 cm below > 1.7 m (sapric-hemic/hemic fibric below 0.6 m)

Table 6c. Kirk’s Fen western soil and water table transect perpendicular to slope. Sampling units listed north to south.

Sampling unit Water table (cm) Rebar depth (m) Soil description to one meter 1 28 cm below 0 m mineral mix 2 25 cm below 1.5 m (sapric-hemic/hemic fibric below 0.6 m) 3 surface > 1.7 m mix (hemic-fibric) mix 4 18 cm below > 1.7 m (sapric-hemic/hemic fibric below 0.6 m) 5 48 cm below > 1.7 m mix (sapric-hemic)

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Table 7a. Radrick Fen soil and water table transect parallel to slope. Sampling units listed south to north.

Sampling unit Water table (cm) Rebar depth (m) Soil description to one meter 1 surface 1.5 m hemic-fibric 2 surface > 1.7 m hemic-fibric 3 surface > 1.7 m hemic-fibric 4 8 cm below > 1.7 m hemic-fibric 5 surface 1.5 m hemic-fibric 6 surface > 1.7 m hemic-fibric 7 surface 1.7 m hemic-fibric 8 surface 1.2 m hemic-fibric 9 surface 1.2 m hemic-fibric Sapric-hemic at surface/ 10 surface > 1.7 m hemic-fibric below 0.6 m

Table 7b. Radrick Fen northern soil and water table transect perpendicular to slope. Sampling units listed east to west.

Sampling unit Water table (cm) Rebar depth (m) Soil description to one meter 3 cm Sapric-hemic at surface/ 1 > 1.7 m standing water hemic-fibric below 0.3 m 2 surface 1.5 m hemic-fibric 3 surface > 1.7 m hemic-fibric 4 surface 1.2 m hemic-fibric 5 surface 0.9 m mineral

Table 7c. Radrick Fen southern soil and water table transect perpendicular to slope. Sampling units listed east to west.

Sampling unit Water table (cm) Rebar depth (m) Soil description to one meter

1 5 cm standing water > 1.7 m hemic-fibric 2 6 cm below > 1.7 m hemic-fibric 3 8 cm below > 1.7 m hemic-fibric 4 8 cm below > 1.7 m hemic-fibric 5 5 cm below > 1.7 m hemic-fibric 6 8 cm below 1.5 m hemic-fibric 7 surface 1.4 m hemic-fibric 8 46 cm below 1.1 m mineral

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Table 8. Change in graminoid dominated area of Matthaei fens between 1949 and 2002 as estimated from aerial photographs.

Year 1949 1955 1963 1969 1980 1985 1990 1995 2000 2002 Kirk’s Fen 0.73 0.63 0.53 0.47 0.33 0.28 0.19 0.10 0.09 0.09 (ha) Radrick 0.81 0.99 0.85 0.72 0.57 0.58 0.56 0.53 0.55 0.56 Fen (ha)

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Table 9. Vegetation not found in either Radrick Fen or Kirk’s Fen currently but listed by Bland (1971) as occurring in seepage bogs at Matthaei Botanical Gardens. Bland defines seepage bog as an “open alkaline bog, often suffused with calcareous waters, e.g., Radrick Bog.” These species may have historically been present in either Kirk’s Fen or Radrick Fen. Names in parenthesis are how the species were listed in Bland (1971), other information including nomenclature are from Herman et al. (2001). Scientific names in all capital letters are adventive species.

SCIENTIFIC NAME C W WETNESS PHYSIOGNOMY COMMON NAME Bidens cernuus NODDING BUR (B. cernua) 3 -5 OBL Nt A-Forb MARIGOLD Bidens coronatus TALL SWAMP (B. coronata) 7 -5 OBL Nt A-Forb MARIGOLD Bidens frondosus COMMON BEGGAR (B. frondosa) 1 -3 FACW Nt A-Forb TICKS Bidens vulgatus (B. vulgate) 0 -3 FACW Nt A-Forb TALL BEGGAR TICKS Bromus kalmii 8 0 FAC Nt P-Grass PRAIRIE BROME Cardamine pratensis 10 -5 OBL Nt P-Forb CUCKOO FLOWER Carex cristatella 3 -4 FACW+ Nt P-Sedge SEDGE CAREX MURICATA 0 5 UPL Ad P-Sedge SEDGE Carex pseudo-cyperus 5 -5 OBL Nt P-Sedge SEDGE Carex vulpinoidea 1 -5 OBL Nt P-Sedge SEDGE Cephalanthus occidentalis 7 -5 OBL Nt Shrub BUTTONBUSH ANDREW'S LADY'S Cypripedium x andrewsii ? ? ? Nt P-Forb SLIPPER VARIEGATED Equisetum variegatum 8 -3 FACW Nt Fern Ally SCOURING RUSH Glyceria grandis 6 -5 OBL Nt P-Grass REED MANNA GRASS KALM'S ST. JOHN'S Hypericum kalmianum 10 -2 FACW- Nt Shrub WORT Juncus nodosus 5 -5 OBL Nt P-Forb JOINT RUSH Panicum implicatum (P. languinosum) 3 0 FAC Nt P-Grass PANIC GRASS Pogonia ophioglossoides 10 -5 OBL Nt P-Forb ROSE POGONIA STELLARIA GRAMINEA 0 5 UPL Ad P-Forb STARWORT

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Nov Oct Sep Aug Jul Jun May Apr Mar Feb Jan Dec Shrub removal w/ herbicide w/ removal Shrub Prescribed burning seedlings of Rhamnus Torching sowing and Seed collection species) target with varies (timing catenatus Sistrurus candidum Cypripedium Sanguisorba canadensis ciliata Valeriana species Invasive wells Water table Herbaceous invasives removal invasives Herbaceous surveys Vegetation Table 10. Annual timing for restoration and monitoring tasks in tasks monitoring and for restoration timing Annual 10. Table fens. Matthaei Restoration Monitoring

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Table 11. Rare plants, insects, and reptiles associated with prairie fens as listed by Spieles et al. (1999) and not currently known in the Matthaei fens.

Plants Berrula erecta Filipendula rubra (cut-leaved water-parsnip) (queen-of-the-prairie) Cacalia plantaginea Helianthus hirsutus (Indian plantain) (whiskered sunflower) Calamagrostis stricta Muhlenbergia richardsonis (narrow-leaved reedgrass) (mat muhly) Carex richardsonii Phlox maculata (Richardson’s sedge) (sweet William phlox) Dodecatheon meadia Polomonium reptans (shooting star) (Jacob.s ladder) Drosera anglica Sporobolus heterolepis (English sundew) (prairie dropseed) Eryngium yuccifolium (rattelsnakemaster)

Insects Celephelis muticum Oarisma poweshiek (swamp metalmark) (poweshiek skipper) Lepyronia angulifera Oecanthus laricis (angular spittlebug) (tamarack tree cricket) Neonympha mitchellii mitchellii (Mitchell.s satyr)

Reptiles Clemmys guttata (spotted turtle) Emys blandingii (Blanding.s turtle) Clonophis kirtlandii Terrapene carolina carolina (Kirtland.s snake) (eastern box turtle)

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Table 12. Vegetation not found in Radrick Fen currently, but listed by Wagner (no date) as being present. This list was probably compiled in the early to mid 1960’s. Names in parentheses are how the species were listed by Wagner, other information, including nomenclature, is from Herman et al. (2001). Scientific names in all capital letters are adventive species.

SCIENTIFIC NAME C W WETNESS PHYSIOGNOMY COMMON NAME Agalinis tenuifolia COMMON (Gerardia tenuifolia) 5 -3 FACW Nt A-Forb GERARDIA AGROPYRON REPENS 0 3FACU Ad P-Grass QUACK GRASS Amphicarpaea bracteata 5 0 FAC Nt A-Forb HOG PEANUT CLASPING Apocynum sibiricum 3 -1 FAC+ Nt P-Forb DOGBANE Aster longifolius LONG LEAVED (A. nova-belgii) 9 -2 FACW- Nt P-Forb ASTER Aster nemoralis 10 -5 OBL Nt P-Forb BOG ASTER Botrychium RATTLESNAKE virginianum 5 3FACU Nt Fern FERN PALE INDIAN Cacalia atriplicifolia 10 5 UPL Nt P-Forb PLANTAIN Cicuta maculata 4 -5 OBL Nt B-Forb WATER HEMLOCK Cypripedium x ANDREW'S LADY'S andrewsii ? ?? Nt P-Forb SLIPPER COMMON Equisetum arvense 0 0 FAC Nt Fern Ally HORSETAIL Eupatorium PURPLE JOE PYE purpureum 5 0 FAC Nt P-Forb WEED FRAGRANT Galium triflorum 4 2 FACU+ Nt P-Forb BEDSTRAW Geum canadense 1 0 FAC Nt P-Forb WHITE AVENS WATER Hydrocotyle umbellata 10 -5 OBL Nt P-Forb PENNYWORT Iris versicolor 5 -5 OBL Nt P-Forb WILD BLUE FLAG COMMON or Juniperus communis 4 3 FACU Nt Shrub GROUND JUNIPER Lilium michiganense 5 -1 FAC+ Nt P-Forb MICHIGAN LILY Matteuccia struthiopteris 3 -3 FACW Nt Fern OSTRICH FERN Muhlenbergia COMMON SATIN frondosa 3 -3 FACW Nt P-Grass GRASS MUHLENBERGIA UPLAND WILD RACEMOSA 0 -3FACW Ad P-Grass TIMOTHY Solidago rigida 5 4 FACU- Nt P-Forb STIFF GOLDENROD TYPHA NARROW LEAVED ANGUSTIFOLIA 0 -5 OBL Ad P-Forb CATTAIL TYPHA XGLAUCA 0 -5 OBL Ad P-Forb HYBRID CATTAIL

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Table 13. Species present in inventory by Reznicek et al. (1999) but not found in inventories for this report. Many of these species were seen in the areas surrounding the fen but not in the open fen or the semi-open shrub borders.

SCIENTIFIC NAME C W WETNESS PHYSIOGNOMY COMMON NAME Actaea rubra 7 5 UPL Nt P-Forb RED BANEBERRY Carex stipata 1 -5 OBL Nt P-Sedge SEDGE Galium tinctorium 5 -5 OBL Nt P-Forb STIFF BEDSTRAW Hydrocotyle americana 6 -5 OBL Nt P-Forb WATER PENNYWORT Lilium philadelphicum 10 1 FAC- Nt P-Forb WOOD LILY Lonicera dioica 5 3 FACU Nt W-Vine RED HONEYSUCKLE Parthenocissus inserta 4 3 FACU Nt W-Vine THICKET CREEPER Pedicularis lanceolata 8 -4 FACW+ Nt P-Forb SWAMP BETONY Platanthera TALL NORTHERN hyperborea 5 -4 FACW+ Nt P-Forb BOG ORCHID Rumex orbiculatus 9 -5 OBL Nt P-Forb GREAT WATER DOCK Saxifraga pensylvanica 10 -5 OBL Nt P-Forb SWAMP SAXIFRAGE

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Unrestricted Restricted: must follow follow must Restricted: seek or guidelines these exception: of 35% than more --no be to habitat wetland burned annually no habitat, quality good --in 3-5 every once than more years to annually habitat, poor --in habitat improve Pre-hibernation (October Pre-hibernation (October –1 31) October follow must Restricted: seek or guidelines these exception: --no burning during this period Restricted: must follow these these follow must Restricted: exception: seek or guidelines -- wetland of 35% than more no annually burned be to habitat more no habitat, quality good --in years 3-5 every once than to annually habitat, poor --in habitat improve Active Season Active 16 –(May 30) September Restricted: must follow these these follow must Restricted: exception: seek or guidelines of wetland 35% than more --no annually burned be to habitat more no habitat, quality --in good years 3-5 every once than to annually habitat, poor --in habitat improve Restricted: must follow these these follow must Restricted: exception: seek or guidelines these follow must Restricted: exception: seek or guidelines to hibernacula of 35% than --no more annually burned be more no habitat, quality --in good years 3-5 every once than improve to habitat, poor --in habitat Unrestricted Restricted: must follow these these follow must Restricted: exception: seek or guidelines of wetland 35% than more --no annually burned be to habitat more no habitat, quality --in good years 3-5 every once than to annually habitat, poor --in habitat improve Restricted: must follow these these follow must Restricted: exception: seek or guidelines period this during burning --no Emergence (April 16 –16 (April Emergence 15) May Restricted: must follow these these follow must Restricted: exception: seek or guidelines of 35% than more --no burned be to habitat wetland annually no habitat, quality good --in 3-5 every once than more years to annually habitat, poor --in habitat improve Restricted: must follow follow must Restricted: seek or guidelines these exception: this during burning --no period Unrestricted Unrestricted Pre-emergence (March 16- 15) April Unrestri cted Unrestri cted Unrestri cted tion (Novem 1 – ber March 15) Hiberna here. : of areas of areas wetlands wetlands Uplands: areas areas Table14. Restrictionsonprescribed burning in massasauga taken habitat from Pearsall andMcGowan-Stinski (2004). defined as as defined 50 m of 50 m 50 m of 50 m known or or known inundated inundated suspected Wetlands: within 500 m 500 within hibernacula areas within within areas or saturated areas within within areas Hibernacula

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Figures

Figure 1. Diagram of idealized fen formation in the landscape from Amon et al. (2002).

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Figure 2. Locations of the Matthaei Botanical Gardens fens on a 2000 aerial photograph, (north is to the top of the page). Each fen can be seen in red and the Matthaei Botanical Gardens building can be seen almost directly in the center of the photo, between the two fens. Kirk’s Fen is located to the north, Radrick Fen to the south. Area of each fen is based on estimations from 1949 aerial photographs.

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Figure 4. Placement of transects, shown as black lines, for soil and water table table water and soil for lines, black as shown transects, of 4. Placement Figure observations in Radrick Fenon 2002 aerial photograph. Blue line shows estimated 1955 shrub line boundary, red line shows estimated2002 shrub line boundary.

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Radrick Fen Year ens at Matthaei Botanical Gardens through Gardens Botanical at Matthaei ens Kirk's Fen Kirk's 1940 1950 1960 1970 1980 1990 2000 2010

1.20 1.00 0.80 0.60 0.40 0.20 0.00

Size (ha) (ha) Size Size Figure 5. Graminoid dominated area of f of area dominated 5. Graminoid Figure interpretation. photograph aerial by time as estimated

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Figure 6. Estimated boundary of graminoid dominated area in Kirk’s Fen (in red) from 1949 aerial photograph.

Figure 7. Estimated boundary of graminoid dominated area in Kirk’s Fen (in red) from 2002 aerial photograph.

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Figure 8. Estimated boundary of graminoid dominated area in Radrick Fen (in red) from 1949 aerial photograph.

Figure 9. Estimated boundary of graminoid dominated area in Kirk’s Fen (in red) from 2002 aerial photograph.

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Albright, M. F., et al. 2004. Recovery of Native Flora and Behavioral Responses by Galerucella spp. Following Biocontrol of Purple Loosestrife. American Midland Naturalist 152, no. 2:248-254.

Amon, J. P., C. A. Thompson, Q. J. Carpenter, and J. Miner. 2002. Temperate Zone Fens Of The Glaciated Midwestern USA. Wetlands 22, no. 2:301-317.

Barnes, B. V. The Oak-Hickory Forest-Radrick Forest. Handout for Forest Ecology course. Matthaei Botanical Gardens Files. University of Michigan. Ann Arbor, Michigan.

Barnes, B. V. and W. H. Wagner, Jr. 2002. Michigan Trees. The University of Michigan Press. Ann Arbor, MI, USA.

Bedford, B. L., and K. S. Godwin. 2003. Fens Of The United States: Distribution, Characteristics, And Scientific Connection Versus Legal Isolation. Wetlands 23, no. 3:608-629.

Bland, M. K. 1971. Checklist of the Native Vascular Flora of the Matthaei Botanical Gardens 1971 Revision. Matthaei Botanical Gardens Files. University of Michigan. Ann Arbor, Michigan. 18 pp.

Bowles, M.L. 1983. The tallgrass prairie orchids Platanthera leucophaea (Nutt.) Lindl. and Cypripedium candidum Muhl. ex Willd: Some aspects of their status, biology, and ecology, and implications toward management. Natural Areas Journal 3:14-37.

Bowles, M., J. McBride, N. Stoynoff, and K. Johnson. 1996. Temporal changes in vegetation composition and structure in a fire-managed prairie fen. Natural Areas Journal 16, no. 4:275-288.

Bowles, M. L., M. D. Jones, and J. L. Mc bride. 2003. Twenty-year Changes in Burned and Unburned Sand Prairie Remnants in Northwestern and Implications for Management. American Midland Naturalist 149, no. 1:35-45.

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