Tucquan Glen
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Lancaster County Natural Heritage Inventory Update 2008 DRYTOWN RD
Run Legend Kellys Species of concern core habitat Natural Heritage Area Roads Supporting Landscape PA Turnpike Streams All other roads Miles Riparian Buffer Municipal Boundary 0 0.25 0.5 1 Tucquan Glen Tucquan Glen – High significance
PNHP Rank1 State Last Observed Species of Concern: Quality2 Global State Status1 (y-m-d)
Plants:
Bradley’s2 spleenwort (Asplenium bradleyi) G4 S1 PE 2006-04-12 D
Lobedspleenwort2 (Asplenium pinnatifidum) G4 S3 PR 2006-04-12 B
Fringe-tree2 (Chionanthus virginicus) G5 S3 PT 2000-07-10 C
Vasey's2 eupatorium (Eupatorium G4 S2 TU 2002-09-13 BC godfreyanum)
St.2 Andrew’s-cross (Hypericum stragulum) G5 S2 TU 2002-09-13 BC Susquehanna trillium (Trillium sp.) G? S? TU 2006 E
Appalachian2 gametophyte fern G4 S2 PT 2005-04-22 B (Vittaria appalachiana)
Exceptional Natural Communities:
Hemlock-tuliptree-birch2 forest GNR S2 NR 1988-11-04 C
1 Please refer to Appendix IV for an explanation of PNHP ranks and legal status 2 Please refer to Appendix V for an explanation of quality ranks
Location: This Natural Heritage Area is a wooded ravine that occurs along the Susquehanna River between Pequea Borough and Muddy Run Reservoir. o Municipalities: o Martic Township o USGS Quadrangles: o Holtwood Quadrangle o 1990 Lancaster Natural Areas Inventory reference: o “Tucquan Glen – NC620” – (Holtwood Quadrangle)
Description: This area contains a narrow, scenically outstanding, forested ravine that ends at the Susquehanna River. The area supports a lush, diverse, relatively undisturbed herbaceous undergrowth. There are frequent rock outcrops of Wissahickon schist in the lower portions of the ravine, especially near the mouth of the stream and high up both slopes. Clusters of hemlock and rhododendron cast pockets of deep shade and provide cool, moist microhabitat conditions along portions of the creek. Six plant species of concern are currently known to occur in this Natural Heritage Area. In addition, the hemlock-tuliptree-birch forest present within the ravine is a high-quality example of this forest community type. The age of the trees suggest nearly old growth conditions. This forested natural landscape functions as an important terrestrial component of the Susquehanna River regional migratory corridor.
Species of concern considerations: Plants: o Bradley’s spleenwort is a fern of very limited distribution in Pennsylvania. Removal of the forested canopy around rock outcrops could alter the microhabitat conditions that the fern presently benefits from; therefore, logging operations should not occur within the core habitat for this species. All of the currently known populations of this plant in PA occur on rock outcrops along the Susquehanna River or other scattered locations in Lancaster County. Since a disproportionate share of this plant’s limited occurrences in PA are in Lancaster County, the County has a proportionally large
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responsibility for its continued existence in the state. The exact location of this species at all locations in the county should be limited to authorized researchers to avoid its extirpation by unauthorized collection. There are numerous outcrops in this area that potentially support additional populations of this species. Additional surveys are recommended to more accurately determine the current extent of this species. o The lobed spleenwort is a small fern that utilizes the lightly shaded rock outcrops as its primary habitat. There are numerous outcrops in this area that potentially support additional populations of this species. Removal of the forested canopy around rock out crops could alter the microhabitat conditions that the fern presently benefits from; therefore, logging operations should not occur within the core habitat for this species. o Fringe tree at this location is sparsely scattered on the lower and mid-slope portions of the river- facing hill. Though this species is native to nearby portions of the lower Susquehanna River shore, this population is considered suspicious due to its proximity to a former cabin site. It may be the result of cultivation at this location. o This population of Vasey’s eupatorium is growing in a narrow band of lower slope along the railroad rights-of-way between Reed Run and Tucquan Creek in dry, schist-derived substrate. This plant is adapted to the disturbed, open conditions created by this railroad and will likely persist in the absence of competition from invasive species. Indiscriminate use of herbicides for vegetation management is not advisable in this location. This plant will likely respond favorably to the reduction of competition through periodic mowing and targeted spot treatments with herbicides. Maintenance activities should consider their impact on this and other rare plants in the rights-of-way. o St. Andrew’s cross occurs in the disturbed conditions created by the construction and continued maintenance of the railroad paralleling the Susquehanna River. This plant is adapted to the disturbed, open conditions created by this railroad and will likely persist in the absence of competition from invasive species. Indiscriminate use of herbicides for vegetation management is not advisable in this location. This plant will likely respond favorably to the reduction of competition through periodic mowing and targeted spot treatments with herbicides. Maintenance activities should consider their impact on this and other rare plants in the rights-of-way. o Susquehanna trillium, a form of trillium of indistinct taxonomy, is found in great profusion among some of the ravines of the lower Susquehanna River, is also present at this location. This plant has an unclear taxonomic status, as it may represent a form of the declined trillium (Trillium flexipes), a white-flowered form of the purple trillium (Trillium erectum), or possibly a hybrid between these two species. This taxonomic puzzle needs to be investigated further, but either way, the populations of these trilliums are worthy of conservation action. Conservation of the rich forested habitat should provide the protection needed for this species. Unauthorized collection for wildflower gardens is also a potential threat. o The Appalachian gametophyte fern occurs in rock crevices and overhangs with a microhabitat featuring dampness, shade, coolness and competition from only a few mosses. Additional potential habitat occurs among the steep, nearly inaccessible cliffs nearby. Changes in the adjacent tree canopy cover could result in drier, warmer microhabitat conditions, diminishing the habitat available for this species at this location; therefore, logging should be avoided within the core habitat for this species. In addition, the hemlock woolly adelgid, an introduced insect pest on hemlock trees, poses a similar threat by killing hemlock trees, which help provide the cool, moist habitat conditions at this location. Exceptional Natural Communities: o The hemlock-tuliptree-birch forest present within the ravine is a high-quality example of this forest community type. The age of the trees suggest nearly old growth conditions. The hemlock component of the forest is in jeopardy due to the infestation of hemlock woolly adelgid and would benefit from timely introduction of verified biological control agents for the pest.
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Forest Cover/Natural Communities: The plant community types depicted are approximations delineated from 2005 aerial photography interpretation and were followed up with minimal selective ground-truthing. Community types follow “Terrestrial & Palustrine Plant Communities of Pennsylvania” (Fike 1999) where appropriate, and otherwise describe general land cover types (*). o Forests cover almost the entire area of this Natural Heritage Area, with only minimal incursions from residences, roads and utility rights-of-way. An unpaved access road down through the glen breaks up an otherwise intact block of interior forest. Portions of two interior forest blocks are included in this Natural Heritage Area. The cool, moist slopes along Tucquan Creek are dominated by a hemlock- tuliptree-birch forest. On the drier, upper slopes a tuliptree-beech-maple forest dominates. The slopes draining directly into the Susquehanna River are dominated by dry oak-mixed hardwood forest and dry oak-heath forest. A narrow band of sycamore (river birch)-box elder floodplain forest occupies the river floodplain. o Terrestrial (upland) communities: o Hemlock-tuliptree-birch forest o Tuliptree-beech-maple forest o Dry oak-mixed hardwood forest o Dry oak-heath forest o Dry oak-heath woodland o modified successional forest* o grass-shrubland* o Palustrine (wetland) communities: o Silver maple floodplain forest o Sycamore (river birch)-box elder floodplain forest
Ownership: This Natural Heritage Area is narrowly drawn to focus on the habitat for the seven species of concern found at this location. o The Lancaster County Conservancy owns approximately 80% of the core species of concern habitat, ~60% of the Natural Heritage Area, and ~35% of the supporting landscape for this area. o PPL Corporation owns utility rights-of-way across the northeastern portion of the Natural Heritage Area and an additional rights-of-way across the northeastern portion of the supporting landscape. o The Norfolk Southern Railroad Corporation owns a rights-of way along the shoreline of the Susquehanna River. o Most of the remaining portions of the Natural Heritage Area and supporting landscape are held in relatively large parcels, which are more constructive towards conservation easements or acquisition transactions than numerous smaller parcels.
Habitat Disturbances: o Historic – o Aerial photos from the 1940’s show that very little has changed in Tucquan Glen in the past 65 years. The area, then as now, had a continuous forested canopy with a dense grove of coniferous forest in the steep-sided ravines near the creek’s confluence with the Susquehanna River. There appears to have been an increase in coniferous forest cover upstream since the 1940’s, perhaps the result of growth since previous lumbering activity. o The unpaved road though the glen was already in place and was used as access for several home sites and seasonal cabins that were scattered though the area. o Most of the current agricultural fields, residences and the utility and railroad rights-of-way were already in place by the 1940’s. o Current – o River Road cuts through the northeastern portion of the Natural Heritage Area. o Some lumbering has occurred on the north slope of the ravine, adjacent to the preserve.
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o The railroad along the Susquehanna River restricts animal movement between the river, its floodplain and upland habitats. o The roadways, utility corridors and railroad fragment the otherwise continuously forested habitat and provide access for invasive and edge adapted species to forest interior habitats. o The seasonal cabins that once occurred in the glen have since been removed from the Lancaster County Conservancy owned property, but these locations remain as outposts for invasive plant species within an otherwise relatively invasive-free habitat. o Agricultural fields occur on adjacent lands and contribute to the fragmentation of the forested habitat. o A campground operates on property adjacent to the Lancaster County Conservancy Tucquan Glen Preserve. Currently, little disturbance of the forested habitat appears to have taken place, as the primary campground area occurs on former agricultural land. o Overbrowsing by white-tailed deer (Odocoileus virginianus) is a serious threat to the overall understory plant diversity. An overabundance of deer can create the effect of park-like forests in which the understory and vertical stratification is greatly reduced. Removal of understory species eliminates habitat for some nesting songbirds as well as increases competition between deer and other wildlife due to reduced food sources. Furthermore, deer prefer higher quality food leaving poorer, less diverse species to mature and dominant the overstory. o Exotic Species – There are a number of invasive plant species established mainly at the edges of the ravine. A large patch of bamboo occurs along a tributary to Tucquan Creek adjacent to River Road. Bamboo is planted as an ornamental, but spreads though aggressive root rhizomes to form dense monocultures. Bamboo does not spread by seed in our climate, but if pieces of root become dislodged from the parent plant, they can establish new colonies. English ivy persists at old cottage sites and represents a serious threat to this special habitat. This weed should be hand-pulled and burned or hauled out of the site. An insect pest on hemlock trees, the hemlock woolly adelgid, which was accidentally introduced from Asia, and has killed numerous hemlock trees in the glen. Additional information on this insect pest can be obtained from the PA Bureau of Forestry web site
at < http://www.dcnr.state.pa.us/for2 estry/woollyadelgid/index.aspx >. If this insect pest succeeds in decimating the hemlock population at this location, it could have a dramatic affect of the microclimate of the glen, creating a drier and warmer environment. The list below represents those invasive plants noted in past field surveys. Additional surveys will likely reveal more recent additions such as Japanese stilt grass (Microstegium vimineum) and tree-of-heaven (Ailanthus altissima). o Bamboo (Pseudosasa japonica) o Garlic mustard (Alliaria petiolata) o Day lily (Hemerocallis fulva) o English ivy (Hedera helix) o Gill-over-the-ground (Glechoma hederacea) o Multiflora rose (Rosa multiflora) o Barberry (Berberis thunbergii) o Japanese honeysuckle (Lonicera japonica)
Conservation Actions:
Overall: • Safeguard the quality and expanse of the forested landscape. While providing the primary habitat for the populations of species of concern, the forested landscape also helps to protect water quality of the small streams that drain through this area into the Susquehanna River and provides refuge and habitat for other forest dependent species. This forested natural landscape also functions as an important terrestrial component of the Susquehanna River regional migratory corridor. Prevent
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fragmentation and incursions into the forested landscape. Suppress the establishment and spread of invasive species of plants. Encourage the regeneration of native trees, shrubs and herbaceous layers. The forest cover should be allowed to maintain old-growth characteristics. • This site should be considered a moderate priority for conservation acquisition, since much of the vulnerable habitat is already under the protection of the Lancaster County Conservancy.
Within the Core Habitat: • Provide for the long-term protection of the core habitat. • Much of the priority core habitat within Tucquan Glen, including both sides of the lower portions of the creek, is owned by the Lancaster County Conservancy, whose mission statement provides for the continued protection of lands under its ownership. • On the adjacent private property, the steep, rocky nature of the immediate habitat of the species of concern likely prevents most types of development activity. The flatter hilltops, however, could prove tempting building sites. Logging of the adjacent slopes is a potential concern. Consider fee-simple acquisition, or conservation easement options with the largest property owners of the core habitat outside of the Lancaster County Conservancy. Focus conservation actions on properties bordering Tucquan Creek just southwest of River Road in order to provide protection for the entire Tucquan Glen. Second, consider fee-simple acquisition, or conservation easement options with the owner of the southwestern portion of the Natural Heritage Area. This parcel contains portions of the species of concern core habitat and parts of a block of interior forest. • Conserve the intact forest canopy. • Avoid additional fragmenting features such as roads, buildings, and utility rights-of-way. • Consider closing the unimproved roadway that extends through the center of Tucquan Glen. Closure of this road will help expand the interior forest component of this landscape by joining two interior forest blocks separated by this fragmenting feature. • Provide biological controls to reduce the damage to hemlock trees from the introduced pest – hemlock woolly adelgid. • Avoid logging activities in this area to develop and maintain old growth conditions. • Remove invasive species of plants. • Invasive species are not currently a primary detriment to Tucquan Glen, which is an excellent reason to take an aggressive approach to invasive species control. It is much easier and more effective to keep a place invasive-free than to try and repair a heavily infested habitat. Target pioneer populations of invasive plants for immediate and continued removal, particularly English ivy, tree-of-heaven, non-native bush honeysuckles, Japanese honeysuckle, multiflora rose and common privet. • Invasive species are a significant feature of the railroad rights-of-way. However, indiscriminate use of herbicides as rights-of-way defoliants is not acceptable. A smarter, more selective use of chemical controls is required in these areas that contain both invasive species and species of concern. Mechanical control, (mowing) is an option that will also require attention to the location and timing of mowing. Early-mid spring season mowing will result in stunted growth for most of the invasive species. Allow the plant species of concern to bloom and set seed before late season mowing takes place. • Invasive species management needs to be coordinated by individuals familiar with the species of concern as well as the invasive species present. • Continual invasive species monitoring and control will be necessary.
Within the Natural Heritage Area / Supporting Landscape:
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The supporting landscape for this Natural Heritage Area is derived from a portion of the Tucquan Creek watershed that contains prominent interior forest blocks. Activities within this portion of the watershed can have a direct impact on the core habitats of the Natural Heritage Area and the species of concern it contains. • Adjacent forested properties should be acquired or provided with conservation easements to help provide a buffer to this habitat and to help provide connectivity to other nearby Natural Heritage Areas. Additional populations of species of concern may occur on adjacent parcels. • The campground adjacent to the Lancaster County Conservancy preserve is on land that was formerly agricultural fields. Some portions of the adjacent forest are being utilized as campground expansion. Rather than carve up the forest for campground expansion, consider reforesting adjacent former agricultural lands to provide additional campground lots. • Agricultural fields within the Natural Heritage Area should be encouraged to return to forest to expand the area of interior forest at this location. • Remove invasive species of plants. • Avoid logging in this area. • Allow the forest to return to near old-growth conditions. • Leave fallen trees in place to help build soil nutrients, humus, tilth and animal microhabitats. Trees that have fallen over approved trails can be cut through as necessary. • Improve the forest composition by removing non-native trees and shrubs. The railroad rights-of-way and the edges of River Road are the primary location of non-native trees and shrubs within this area. • Encourage native tree and shrub recruitment. Reduce the size of the deer herd. Uncommon native species of plants are particularly susceptible to deer herbivory. High deer numbers severely increase tree seedling mortality. Without successful tree seedling recruitment, future forest health will be in jeopardy. • High levels of public activity are potentially detrimental to the habitat, so only passive recreation should be allowed to occur. • Block access to forested areas by off road vehicles, ATVs, motorcycles and bicycles. • Streams through forested areas should be considered high priority for conservation. Streams through non-forested areas should be restored with native trees, shrubs and wetland plants as appropriate to the topography and hydrology. • Careful determination is needed to avoid planting trees in floodplains that should remain as herbaceous wetland habitats. These habitats should be maintained in their current open condition, with tree plantings to occur at the periphery of natural wetland openings. • An ideal vegetated stream buffer should be at least 100 meters (~300 feet) in width from the edge of the 100-year floodplain. • An intermediate vegetated stream buffer should be at least 100 feet in width from the edge of the 100-year floodplain. • A minimum vegetated buffer should be at least 35 feet in width from the edge of the 100- year floodplain. • Additional surveys for species of concern are recommended. • Potential zoning options for conservation enhancement: • Strict enforcement of regulations restricting building activity on slopes greater than 25% will provide protection for almost all of the area within the core habitat, ~90% of the Natural Heritage Area and ~40% of the supporting landscape. • Zoning regulations should discourage further fragmentation of contiguous or interior forest blocks. Adjacent parcels currently forested should be zoned to conserve this attribute.
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• Adjacent parcels currently in agriculture that are of high quality agricultural soils should be zoned agricultural and considered fully built out. Poorer quality agricultural soils should be encouraged to regenerate into forest cover. • Growth within the Township should be discouraged to occur within the core, Natural Heritage Area or supporting landscape identified for this area.
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