Page 1

Technical Elements of the Park Master Plan

~alrmount

NATURAL VEGETATION

PrepdJ:ed for The Fairmount Park

COW~i2sion

by

The Morris

A~boretum

December 1983


This repon is one of a series of documents of dle Fairmount Park Master Plan which include inventory maps, summary exhibit maps and technical reports. All of these documents are available for study !l"d review at me offices of the Fairmount Park Commission, Memorial Hall, West Park. Philadelphia, Pennsylvania 19131. . Inventory Maps Sepias of the Faitmount Park System at scales ranging from 1 "=50' to 1"= 100' record findings of field surveys, J ulr through Septembcr, 1983, with regard to type and condition 0 Park facilities. and vegeta.tion and recommended landscape maintenance levels throughout the Park, and It)cations of major utility Jines throughout the Park.

Exhibit Maps \linc large scale color exhibits of the Park System at scalcs ranging from 1"=500' to 1"=700' illustrating each of the following categories of information: 'oils by type, natural vegetarian by plant community lind .Ievel of Ji rurbance, recreation facilitks, surrounding land uses. community groups and planning is ues, proposed street jurisdiction and maintena.nce, and ;ummary of Master Plan recommendations. City-wide maps at a scale of 1"=2400' illustrating geology of the Fairmount Park System, Philadelphia's natural and storm drainage systems and known historic resources of the Park System.

Technical Elemefits of the Plan: Additions and Changes to Report No.2, Management of the Park System, December, 1983. Technical Elements of the Plan: Financing the Operation of the Park System, December, 1983. Technical Elements of the Plan: Additions and Changes to Report No.3, Recreation Resources and Park Use, December, 1983. . Technical Elements ofthe Plan:

Wa~er

Qolaliry, December, 1983.

Technical Elements of the Plan: Natural Vegetation, December. 1983. Technical Elements of the Plan: Designed Landscapes, December, 1983. Technical Elements of the Plan: Archaeological Resonrces, December 1983.

Reports

Technical Elements of the Plan: Historic Resources, December. 1983.

Existing Conditions and their Implications for the Master Plan; Report No, 1, Executive Summary, September, 1983.

Te~hnical Elements of tbe Plan: Additions and Chan~s to

Existing Conditions and their Implications for the Master Plan i Rep(1rt No.2. Management of the Park SYStem, September, 1983. Existing Conditions and their Implications for the Master Plan; Report No.3. Recreation Resources and Park Use, September, 1983. Existing Conditions and their Implications for the Master Plan; Report No.4, Water Quality, October, 1983. Existing t:onditions And their Imp lications for the Master Plan; Report No.5, Natural Environment, September. 1983. Existing Conditions and their Implications for the Master Plan; Report No.6, Designed Landscapes, September, 1983. Existing Conditions and their Implications for the Master Plan; Report No.7, Archaeological Resources, October, 1983. Existing Conditions and their Implications for the Master Plan; Report No.8, Historic Resources, September, 1983. Existing Conditions and their Implications for the Master Plan; Report No.9. Circulation Access, Parking and Signage, September, 1983. Existing Conditions and their Implications for the Master Plan; Report No. 10, The System's Park, September, 1983.

Report No.9, Circulation, Access, Parking and Signage, December, 1983.


Technical Elements of the Fairmount Park Master Plan

NATURAL VEGETATION

Prepared for

l

The Fairmount Park Commission

I'

by

Ann F. Rhoads, Ph.D. Richard H. M. Mellon, B.Sc.

The Morris Arboretum December 1983


Table of Contents Introduction

1

Outstanding Vegetation Features

4

Forests

8

Open and Wetland Habitats

18

Exotic Species

20

Dumping and Littering

23

Interpretation Of the Natural Landscape

24

Management and Maintenance

26

Cost Implications

27

Appendix A: Explanation oÂŁ Mapping Units

28

List of Figures

Parks in the Fairmount Park System with Natural Landscape Features

3

Major Critical Environmental Areas

7

Forest Succession in Fairmount Park

12

Generalized Forest Structure

13

Forest Succession Patterns with Respect to Aspect

14

Effects of Disturbance in a Typical Mature Forest

22


INTRODUCTION Overview of the Natural Landscape of Fairmount Park The wooded slopes and valleys which comprise a major portion of the Wissahickon, Pennypack, Cobbs Creek, Tacony, and Poquessing sections of Fairmount Park, as well as parts of the East and West Parks and several other scattered sites, are a living reminder of the great deciduous hardwood forest which once covered eastern Pennsylvania. They are also the backbone of the Park, providing a natural setting for diverse activities. The forests, fields, floodplains, and wetlands are used for hiking, horseback riding, nature study, wildflower walks, bird watching and contemplation. They also constitute substantial green corridors in the landscape, reducing erosion, pollution, and noise. They have been aptly characterized as the lungs of the city. As biological systems, forests are dynamic, changing with time and in response to alterations in the physical environment. Human activity has accelerated the change in many areas, affecting both the quantity and the quality of the natural landscape. In order to evaluate the current condition of the natural vegetation of Fairmount Park and provide information needed for preparation of a master plan, the Morris Arboretum of the University of Pennsylvania conducted a reconnaissance inventory during the period July, August, and September 1983. . Definition and Methods of Study Natural areas were defined as forests, old fields, meadows, and floodplains: essentially those areas which were not receiving regular horticultural maintenance. Vegetation types were delimited preliminarily with the aid of stereo pairs of aerial photographs (1 inch = 800 feet) taken in March of 1981, provided by the Fairmount Park Commission. Photographs were examined in the laboratory with a stereoviewer to identify areas of natural vegetation and determine boundaries of vegetation types. Each vegetation unit was subsequently visited on foot to verify the type of plant community present. Vegetation types were classified according to a seven place code based upon: vegetation structure, moisture gradient, size class, characteristic species, and percentage of nonnative species present. (See Appendix A for a complete explanation of the code.) Vegetation types were encoded and mapped at 1 inch = 100 feet; these maps are available for review at Memorial Hall.

1


Following ground verification, vegetation units were outlined on topographic maps (1 inch = 100 feet) and identified by the appropriate code. Subsequently, color-coded summary maps (1 inch = 500, 600, 700 feet) were prepared for each Park unit to indicate generalized vegetation types. These maps are available for review at the Fairmount Park Commission, Memorial Hall. In addition, written descriptions. were prepared for each vegetation type including: structure of canopy, understory, shrub and herbaceous layers, dominant species, rare or unusual species, habitat delineators, soil type, moisture and exposure. Resource Protection Priorities The forests, fields and wetlands constitute a vital natural resource which determines the character of Fairmount Park. Protection and augmentation of this resource must be a paramount concern. Forest remnants, individual plants and plant communities included in the list of Outstanding Vegetational Features should be a top priority for protection from possible harmful effects. All present and proposed land uses should be reviewed to make sure they will not have a negative impact on these valuable natural features. The preservation of all large contiguous tracts of forest habitat should also be a high priority. It is essential that these areas not be fragmented any further if maximum wildlife diversity is to be maintained. Local colleges and universities should be encouraged to undertake biological monitoring programs within the Park. This would result in the generation of specific information needed for effective resource management. A system of nature centers should be developed to use the natural and cultural resources tof Fairmount Park as the basis for involving children and adults in constructive activities. While the nature centers should be located in the Park and make use of Park facilities, they should largely be operated by existing private or public educational institutions.

2


OUTSTANDING VEGETATION FEATURES Loca~ion

and Identification

During the field study a list of outstanding vegetation features was developed. Criteria used in developing this list were: stands where trees average more than 40 cm DBH (Diameter at Breast Height), stands with less than 10% nonnative species, individual trees of great size or age, presence of rare or unusual plant or animal species, and the best example of each natural habitat type present in the Park. An annotated list of the outstanding vegetational features follows. Outstanding Natural Vegetational Features Northwest Philadelphia: Carpenter's Woods - best mature oak forest in the Park; an important site for migrating warblers in the spring. Andorra Natural Area - successional forest with unusual species diversity due to an early nursery (the former Andorra Nursery) located on the site. Upland meadow between Wissahickon Avenue and Cathedral Road - excellent example of a xeric meadow; grasshopper sparrows have nested here. Forbidden Drive - mature stands of tulip tree, oak and beech occur all along the drive, contains some of the tallest trees in southeastern Pennsylvania. Floodplain forest along the Wissahickon Creek north and south of Bells Mill Road - best example of this forest type in the Park. ' Tulip tree/ash forest along the south side of Bells Mill Road west of Wissahickon Creek - best example of this forest type in the Park. Oak/beech forest south of Bells Mill Road on the west side of the Wissahickon Creek - best example of this forest type in the Park. Tulip tree forest north of Valley Green Road on the west side of Wissahickon Creek - best example of a mature tulip tree forest in the Park. Tulip/beech and hemlock/hardwood forests along the east side of the Wissahickon Creek from the Monastery north for approximately three quarters of a mile - best example of these forest types in the Park.

4


Aster spectabilis site near Wissahickon Avenue and Hortter Street - one of only two recorded locations for this rare species in Pennsylvania. Herbaceous "old field" habitat at Germany Hill Park. Additional mature and/or undisturbed stands as indicated on the map. East and West Parks: Mature forest west of Chamounix in west Park. This area and the three following were the only sizeable tracts of forest left in West Park in 1876. Mature forest at the northern end of Robert's Hollow in West Park. Mature forest southwest of the Fairmount Park Recycling Center in west Park. Mature forest in a portion of the ravine north of Memorial Hall in West Park. Forested ravine northwest of the East Park Reservoir (Near Ormiston Mansion) - the only mature forest remnant in East Park. Pennypack Park: Grove of large black walnut trees south of Verree Road on the west side of pennypack Creek along the bike path. Grove of large oaks north of Holme Avenue between Lewin Place and Convent Avenue. Mature oak/beech forest between Verree Street and Krewstown Road - an excellent example of this forest type. Willow/buttonbush/spatterdock swamp between Rhawn Street and the Pennypack Creek - one of the few wetlands in the Park; should be preserved for the added habitat variety it provides. Tidal marsh at the mouth of Pennypack Creek - the only example of this habitat type in the Park; includes a small stand of Sagittaria subulata, a plant considered endangered in Pennsylvania. Pennypack Environmental Center interpretive area. Plus all mature and/or undisturbed forest areas as indicated on exhibit maps at Memorial Hall.

5


Cobbs Creek Park: Stand of elephant foot (Elephantopus carolinianus) in Carroll Park at the north end of Cobbs Creek Park - one of only a few locations known for this species in Pennsylvania. Abandoned golf course (Karakung) - area has become excellent open field habitat. Plus additional mature and/or undisturbed forest areas as indicated on exhibit maps at Memorial Hall. Tacony Creek Park: Open "old field"

habitat north of Wyoming Avenue.

Mature forest grove in the northern end of the Park. Germantown, Olney and Oak Lane: Mature oak/beech forest which comprises most of wister Woods Park. Management Guidelines Components of the list of outstanding vegetation features should be protected from uses that could lead to habitat degradation. Both existing and planned land use patterns should be evaluated in terms of impact on these valuable natural features. Restriction of certain kinds of activities, such as horseback riding, may be justified in some cases.

6


FORESTS Locations of Forests in Fairmount Park The forested lands of Fairmount Park lie mainly in five stream valleys: Cobbs Creek, Wissahickon Creek, Tacony Creek, Pennypack Creek, Poquessing Creek, plus several ravines in East and West Parks. Forest maturity, judged by species composition and DBH size classs, varies greatly throughout the Park. The most mature forests, those with trees greater than 40 cm DBH, occur on the steepest slopes. Although they may have been logged in the past, these areas were probably never farmed. Areas notable for mature native forest trees include the slopes along Forbidden Drive in the Wissahickon section, several parcels of oak, beech and tulip tree forest west of Krewstown Road in Pennypack Park, the ravine area west of Chamounix Mansion in West Park and the area southwest of the recycling center off West River Drive. Younger forests, characterized primarily by tulip tree and associated hardwoods comprise a major part of the Fairmount Park forest; occupying more nearly level upland and bottomlands which were cleared and farmed at some time in the past. Floodplain forests occur along most of the creeks and smaller tributaries. Forest Types Present Xerophytic Forest (FX-----) This community occupies the dry, ridge-top, forested habitat and is dominated by chestnut oak (Quercus prinus). Other species of oak, wild black cherry (Prunus serotina) and sour gum (Nyssa sylvatica) may also be present as canopy associates or understory species. The shrub layer contains mountain laurel (Kalmia latifolia) and/or maple leaf viburnum (Viburnum acerifolium). The herb layer tends to be rather limited, but trailing arbutus (Epigea repens), white woodland aster (Aster divaricatus) and other acid-loving plants do occur. The soils are thin, sandy, very acidic, well-drained and low in organic matter and moisture holding capacity.

B


MeSophytic Forest (FM-----) lÂŁied Nine types of native mesophytic forest have bet in the Park. Tulip/ash is a cove forest, occup :lownutrient rich protected coves that surround strt m. th, ing into the major creeks. This area contains r ~~ : or abundant diversity and little natural threat frol tree flooding. The dominant canopy species are usuall t (Liriodendron tulipifera) and green ash (Fraxinus el vanica) but many other species abound. Spicebush benzoin) is the dominant shrub, while the herb layl cally contains Christmas fern (Polystichum acrostic 1i dolls eyes (Actaea pachypoda), jewelweed (Impatiens ~) and wood nettles (Laportea canadensis). The soils a erally rich in nutrients and exhibit good soil textu. '. Tulip tree forests include a variety of co-dominants ing ash (Fraxinus americana), maple (Acer saccharum), a~ wood (Tilia americana), black birch (BetUla lenta), oa (Quercus spp.), beech (Fagus grandifolia), and hemlock canadensis). Spicebush (Lindera benzoin) dominates the ,n layer. Herb layer plants include Christmas fern (Polys\ Cl acrostichoides), wild ginger (Asarum canadense), and jac ~ the-pulpit (Arisema triphylla). Tuliptree associations, found on rich, rather deep loam soils with pH usually abo = 5.5. Oak/beech and oak forest types are very similar and occupy the opposite end of the local pH scale from the tuliptree forest. Whereas the tulip tree forest is the most alkaline forest type (pH 5.5) in Fairmount Park, the oak/beech and 08 forests are the most acid (pH 5.0). As a result, few plant species occur in both areas. Dominant tree species are red oak (Quercus rubra), white oak (Q. alba), black oak (Q. velutina), and beech (Fagus grandifOIIa). The shrub layer is characterized by maple leaf viburnum (Viburnum acerifolium) , mountain laurel (Kalmia latifolia) and pinxter bloom azalea (Rhododendron nudiflorum). The oak/beech association occurs on steep but moist slopes, whereas the mixed oak forest often occurs on relatively level ground that has a tendency to be droughty. Soils in both habitats tend to be very 'acidic (pH 5.0), well-drained, and often sandy with poor structure and low nutrient holding capacity. Tulip/beech and hemlock hardwood communities occupy a niche midway between tulip tree and oak or oak/beech forests, typically containing components of both. In the shrub layer, spicebush (Lindera benzoin) shares dominance with maple leaf viburnum (Viburnum acerifolium), arrowwood viburnum (V. dentatum), and mountain laurel (Kalmia latifolia); while in the herb layer, white woodland aster (Aster divaricatus) and New York fern (Dryopteris noveboracensis) occur with species typical of the tulip tree forest. Soils also tend to be intermediate with pH between 5.0 and 5.5 and nutrients and

9


structure moderately well developed. Individual-differences between tulip/beech and hemlock/hardwood communities ar~ generally due to the cooler and more moist conditions requlred by Canadian hemlock (Tsuga canadensis). In the Wissahickon, black birch (Betula lenta) stands have developed after fire destroyed the earlier forest structure. In Tacony Park, wild black cherry (Prunus serotina), is a pioneer species in similar situations. Both form monocultures on sterile acidic soils with associated acid-loving herbs. As pioneer trees, they are eventually replaced by shade tolerant forest species as succession proceeds. Ash/cherry forest is a common successional stage on disturbed (non-fire) sites.' White ash (Fraxinus america) occurs with cherry (Prunus serotina) and several other deciduous species. Generally, these habitats are of moderate acidity with fairly rich soils which have been alter~d by cultivation or compaction. Floodplain Forest (FF-----) This forest type occurs in level areas along the streams where seasonal flooding is frequent. Characteristic tree species include box elder (Acer negundo), sycamore (Platanus occidentalis), silver maple (Acer saccharinum), black walnut (Juglans nigra), green ash (FraxTnus pennsylvanica) and tuliptree (Liriodendron tUlipifera). The understory is usually young canopy species, while the shrub layer, if present, consists of spicebush (Lindera benzoin) with some areas of arrowwood viburnum (Viburnum dentatum) or bladdernut (Staphylea trifolia). The herb layer is dominated by coneflower (Rudbeckia laciniata), nettles (Urtica dioica and Laportea canadensis), jewelweed (Impatiens capensis) and in more disturbed areas, giant ragweed (Ambrosia trifida). Exotic species such as Japanese knotweed (Polygonum cuspidatum) are a frequent occurrence due to the periodic natural scouring of the stream banks. The term "forest glade" was used to describe open wooded areas with scattered large trees providing less than 70% canopy cover. Xerophytic Glade (GX-----) This is essentially a grassland habitat with the addition of scattered black cherry (Prunus serotina), oak (Quercus spp.) or sassafrass (Sassafras albidum).

10


Mesophytic Glade (GM-----) Tuliptree (Liriodendron tulipifera) and white ash (Fraxinus americana) are often present and grape (Vitis sp.) is a common component of the understory and shrub layers. Floodplain Glade (GF-----) This area has physical and botanical components similar to the floodplain forest. However, it tends to be more open and usually lacks shrub or understory layers. Forest Dynamics Eastern Pennsylvania lies in the deciduous forest zone of North America. Before human intervention, the entire area was a vast woodland. There are no primeval forest remnants remaining in Fairmount Park. Most areas close to the city were cut over for lumber and firewood more than 200 years ago. In addition, the demise of the American chestnut, victim of a fungal disease introduced from Asia during the early part of this century, brought about significant changes in forest stand composition. In 1907 chestnut accounted for 45 to 49 percent of t~e basal area in old growth forests remaining in West Park. Today it is represented by root sprouts which rarely reach sapling size. However, there are stands of mature, relatively undisturbed native forest which constitute an important resource to the City and the region. Additional stands of late stage successional forest growth provide corridors of woodland along the stream valleys allowing for important landscape and habitat continuity. Extensive open areas of agricultural, residential, and commercial development are the result of cutting and clearing of the primeval forest. If this cleared land is no longer tended regularly and further disturbance ceases, it will again become forested. The process, known as secondary forest succession, has occurred on abandoned agricultural lands throughout the northeastern United States. Secondary succession involves a predictable series of stages, each of which modifies the environment, and leads inexorably to the next. Briefly summarized, the sequence is annual weeds -perennial grasses and forbs -- sun and drought tolerant shrubs and trees -- shade tolerant trees -- stable selfperpetuating forest (Figure C). A mature forest is capable of maintaining itself through reproduction of its component species and is characterized by a stratified structure, including well-defined canopy, understory, shrub and herbaceous layers (Figure D). Specific successional patterns 1

Paul, Oglesby 1908. Report on the Trees of Fairmount Park. 52 pp. Commissioners of Fairmount Park.

11


Figure C. Forest Succession in Fairmount Park XEROPHYTIC SITE

MESOPHYTIC SITE

FLOODPLAIN

Andropogon scoparius Solidago spp.

Grasses & Forbs Rubus spp.

Urtica dioica Laportia canadensis Rudbeckia laciniata

Prunus serotina Sassafras albidum Populus tremuloides Betula lenta

1nI'" a.:.crI ;:.

... ~

~

Quercus spp.

Rhus typhina Prunus serotina Sassafras albidum Acer negundo Acer saccharinum

Fraxinus americana Liriodendron tulipifera Quercus spp. . Juglans nigra Acer rubrum Fraxinus oennsvlvanica Platanus occidentalis

.2 Q.

1

Quercus spp. Carya spp. Fagus grandifolia

Liriodendron tulipifera Quercus spp. Fagus grandifolia

Liriodendron tulipifera Juglans nigra Acer rubrum Fraxinus pennsylvanica Platanus occidentalis


Figure D. Generalized Forest Structure

(

- - - - Canopy Layer

, - - - - Understory Layer

J..IDm DllI~ ~ rrr ~Im cf1'l1l ~ [fIr Shrub Layer -J~e-~-::\f1~b.~ 1f~1~~~~&l11L1~. ~ ~A.~~'A.e~~L~J>..~~"â‚Ź1J~h"\~.~.~~~~~!Zi;a Herbaceous Layer ----- - " " ' - -_ _---.:.:::: Leaf Utter

JD

e::t:_

Topsoil - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Subsoil


Figure E. Forest Succession Patterns with Respect to Aspect Very Acid Forest

1. Bare ground

4(a). Black Cherry

Few annuals

4(b). Black Birch

2. Bluestem Grass Goldenrod Thoroughwort .

5. Hemlock Hardwoods

WEST FACING

SLOPE 5. Oak

_--"l"'"

Beech

5. Oak Beech

4(a). Aspen Sassafras

5. Oak (Chestnut Oak on higher, drier slopes)

Moderately Acid Forest 2. Blackberry Goldenrod Aster

1. Ragweed Fleabane

4. Black Birch

3. Grape Sumac Multiflora Rose

5. Hemlock Hardwoods

WEST

EAST

FACING

FACING

SLOPE

SLOPE

4. Tulip Poplar Ash Dogwood

SOUTH FACING

SLOPE

5. Tulip Poplar Hardwoods


Floodplain Forest (Level ground .• no aspect) 1. Ragweed Nettles Knotweed

2. Coneflower Joe Pye Weed

3. Spicebush Young trees Grape

4. Tulip Poplar Ash Box Elder Maple

5. Tulip Poplar Ash Walnut Sycamore

Key to Figs. C.1., C.2., C.3.

D § .. "· . D ITDJJ " "

Ill"

~

1. Bare Ground / Annuals 2. Perennials 3. Shrubs 4. Pioneer Forest 5. Mature Forest


and the ultimate composition of the mature forest are determined by site factors such as soil type, moisture availability, slope, exposure, temperat~re, the nature and extent of earlier disturbance as well as seed sources. Perpetuation of any vegetation type other than the one naturally adapted to the region requires expenditure of energy. A grassy field or meadow, for example, can only be maintained if periodic mowing or burning is applied to arrest the process of succession and prevent colonization by woody species. Successional patterns found in the areas of Fairmount Park are of three major types (see also Figure E) : 1)

Xeric habitats (dry uplands and steep, rocky areas of thin acidic soils). Little bluestem, goldenrod --- wild black cherry, aspen, black birch, sassafras --- mixed oak species --- oak, hickory, beech forest.

2)

Mesic habitats (mid and lower slopes, soils with greater moisture holding capacity and slightly higher pH). Grasses, forbs, blackberry --- sumac, cherry, sassafras --- white ash, tulip tree --- tulip tree, oak, beech forest.

3)

Floodplains (valley bottoms subject to periodic innundation, deep alluvial soils). Nettles, coneflower --boxelder, silver maple --- black walnut, red maple, green ash, sycamore, tulip tree.

Wildlife Considerations Although the primary emphasis of this study was the vegetation, observations of wildlife were occasionally made during the field work. Unusual birds noted included: acadian flycatchers nesting in the upper Wissahickon Valley, hooded warblers nesting in the Andorra area, cerulean warblers seen near the Covered Bridge, and pileated woodpeckers spotted in Pennypack Park. In addition, Carpenter1s Woods is well known among area bird watchers as an excellent place to see migrating warblers in the spring. Deer were sighted several times in forested areas of Pennypack Park. If a diversity of wildlife is to continue to be a .feature of the Park, then attention must be paid to maintaining critical habitat size. Many species require large tracts of preferred habitat, as much as 100 acres or more, to maintain healthy populations. Large contiguous tracts of forest must be protected from further fragmentation if critical habitat sizes are to be preserved. Specific systematic information on wildlife is needed for effective resource management. Local schools, colleges and

16


universities should be encouraged to initiate population studies and biological monitoring projects which could generate this information. Organizations such as the Delaware Valley Ornithological Club and the Philadelphia Botanical Club could also assist in gathering valuable data. Management Considerations Appropriate uses - Two major concerns regarding the impact of various uses on forest habitats are soil compaction and erosion. Compaction results when excessive trampling occurs in an area and results in elimination of native herbaceous species and decline of shrubs and trees. Erosion becomes a problem whenever the vegetation cover is reduced or eliminated. Soils of the Manor series, which predominate in Fairmount Park, are very prone to erosion, a condition which is intensified by extensive areas of sloping ground. In general, use of forested areas should be limited to paths and trails. Location of trails, especially bridle trails, should avoid slopes where the erosion potential is highest. In some areas there may be a need to segregate different types of trail users (i.e., hikers, joggers, bicyclists, and horseback riders) in order to avoid conflicting needs and values. Off-trail activities, such as an orienteering program, might be permitted in special cases, however this type of use should be limited to forests where exotic species already comprise a major portion of the herbaceous layer. Automobile access to the network of dirt roads which crosses the forested area southwest of the recycling center in West Park should be limited to emergency vehicles. Further consideration should be given to limiting access in other natural areas, perhaps by closing some trails. Carpenter's woods should be designated as a bird sanctuary and use limited to bird watching and infrequent hiking. Maintenance requirements - In general, forested areas should require very little maintenance. Trail clearance, removal of dead trees along heavily used drives and trails and occasional trash pickup should suffice. Where hiking trails and bridle paths have created erosion problems, check darns or other erosion control measures are needed.

17


OPEN AND WETLAND HABITATS Location and Description of Specific Habitat Types ~,In

addi tion to forests, other natural plant communi ties found within the Park include a willow-buttonbush-spatterdock swamp, a freshwater tidal marsh at the mouth of Pennypack Creek, floodplain meadows along the Pennypack and Tacony Creeks, and upland meadows and old fields. The finest example of upland open habitat is a grassy expanse with scattered clumps of trees off Cathedral Road in the upper Wissahickon. Other notable examples occur in West Park and the lower section of Tacony Park. An abandoned golf course in Cobbs Creek Park is also becoming an interesting " 0 1d field." A description of five open and wetland habitat types follows: Xerophytic Open Areas (OX-----) This is a dry, usually ridge top, open habitat dominated by little blue stem grass (Andropogon scoparius). In most areas it is probably a fire subdominant, requiring burning at least once every ten years to eliminate invading woody species. Species associated with the little blue stern include hyssopleaved thoroughwort (Eupatorium hyssopifolium), gray-stemmed goldenrod (Solidago nemoralis) and mountain mint (pycnanthemum sp.). Soils are well-drained, sandy, very acid (pH 4.0-5.0), with low organic matter and low water holding capacity. Mesophytic Open Areas (OM-----) These areas are usually dominated by forbs, although some former lawn areas have retained dominance by introduced grasses. Later successional stages can include young sassafras (Sassafras albidum), wild black cherry (Prunus serotina) and black locust (Robinia pseudoacacia). Dominant species include ro~gh goldenrod (Solidago rugosa), early goldenrod (~. juncea), small white aster (Aster pilosus), and blackberry (Rubus sp.). Soil is often undifferentiated in the plow layer, poorly to well-drained, with a pH above 5.0, and a variety of textures. Organic matter is usually low with little or no litter layer. Floodplain Meadow (OF-----) Periodic innundation and seasonal scouring maintain open habitat along streams; typical species include coneflower (Rudbeckia laciniata), Jewelweed (Impatiens capensis), Joe pye Weed (Eupatorium fistulosum), and several species of nettles (Urtica dioica and Laportea canadensis); exotic species, especially Japanese knotweed (Polygonum cuspidatum) and cup plant (Silphium perfoliatum) are also common components.

18


Non-Tidal Wetland (ON-----) These areas are characterized by the presence of standing water for most or all of the year; typical species include spatterdock (Nuphar sp.), arrowhead (Sagittaria sp.), purple loosestrife (Lythrum salicaria), giant reed grass (Phragmites communis), buttonbush (Cephalanthus occidentalis) and willow (Salix sp.). Soils have poor drainage due to a clay/silt composition. Tidal Wetland (OT-----) Found at the mouth of Pennypack Creek and in several small areas along the Delaware River immediately south of Pennypack Creek, this community is dominated by spatterdock (Nuphar luteum ssp. macrophyllum). Species diversity at these sites is unusually low with many common associates completely absent; one small patch of subulate-Ieafed sagittaria (Sagittaria subulata), a species which is considered endangered in Pennsylvania, was found. Wildlife Considerations Well established meadows provide habitat for bird species not found in the forest, and are important in adding to the diversity of wildlife in the Park. Grasshopper sparrows路 are known to have nested in an upland field in the Wissahickon. Wetlands, similarly, add to species diversity by providing habitat not available elsewhere in the Park. Management Guidelines Appropriate Uses - All existing wetland habitats should be designated as natural areas and protected from draining, dreding or other disturbance. Particularly fine examples of open habitat, such as those in the Special Vegetational Features list, should also be designated as natural areas. Hiking and horseback riding should be limited to carefully located trails to minimize damage to vegetation and subsequent erosion problems. Maintenance Needs - Open habitat can only be maintained if steps are taken to arrest the natural process of forest succession. Consequently annual mowing or burning is recommended for fields in the upper Wissahickon, Tacony Park, West Park and Cobb's Creek Park. Additions to this Habitat Type The finest expanse of open field habitat is located in the upper Wissahickon off Cathedral Road; only a portion of the total site is actually within present Park boundaries. Acquisition of the remainder of this tract should be a high priority.

19


EXOTIC SPECIES Definition and Significance The presence of exotic (non-native) species and the lack of normal forest stratification are indications of widespread disturbance. Causes of disturbance include earlier cutting or clearing, fire, trampling, erosion, insect defoliation, and flooding (Figure F). Disturbed forests dominate in portions of East and West River Parks, Cobb's Creek, the lower Wissahickon Valley, Tacony Park, and Pennypack Park east of Rhawn Street. Lists of Species and Locations in Fairmount Park Exotic species which have become naturalized in these areas include umbrella tree (Magnolia tripetala), black locust (Robinia pseudoacacia), Amur cork tree (Phellodendron amurense), cedrela (Cedrela sinensis), catalpa (Catalpa bignonioides), Norway maple (Acer platanoides), ailanthus (Ailanthus altissima), empress tree (Paulownia tomentosa), devil's walking stick (Aralia elata), Japanese knotweed (Polygonum cuspidatum), multiflora rose (Rosa multiflora) , Japanese honeysuckle (Lonicera japonica), goutweed (Aegopodium podagraria), and kudzu vine (Pueraria lobata). Although, from a purely ecological point of view, these plants have no place in the native landscape, repeated disturbance has allowed them to become widely distributed often at the expense of the native herbaceous flora. In the Andorra area, the presence of a former nursery on part of the site has led to very diverse and unusual species composition. In most cases, forest succession will eventually result in replacement with more shade tolerant native forest species provided disturbance is kept to a minimum. In floodplains, which are subject to periodic natural disturbance, erradication of exotic species would require continual human interference, a monumental task which would not seem justified given the limited resources available for maintenance. General Policy and Specific Recommendations We do not recommend any attempt to control exotic species in forested areas other than by allowing natural succession to occur. Serious consideration should be given, however, to a program to erradicate two stands of kudzu vine occupying approximately a one-half acre at H Street and Fisher's Lane in Tacony Park and a one acre site behind the 5000 block of Pennway Street along Tacony Creek.

20


This species has been shown to be extremely aggressive and destructive of native vegetation. The National Park Se~vice has recently reported some success in erradicating kudzu 2 using late summer applications of the herbicide Glysophate.

2Rosen, Aaron. 1982. Feasibility Study: Eradication of Kudzu with Herbicides and Revegetation with Native Tree Species. Research/Resources Management Report SER-59. National Park Service.

21


Figure F. Effects of Disturbance in a Typical Mature Forest

STABLE

MODERATELY DISTURBED

HIGHLY DISTURBED

Mature oak, beech, tulip, etc. in canopy layer.

Mature oak, beech, tulip, etc. in canopy layer.

Mature oak, beech, tulip, etc. in canopy layer.

Wall developed understory of dogwood, young red maple, etc.

Sparse understory: presence of dying trees.

Understory very poorly developed or absent.

Diverse shrub layer including native viburnums, pinxter azalea, witch-hazel, amelanchier, etc.

Shrub layer sparse: predomi路 nantly spicebush.

Few or no shrubs.

Highly diverse herbaceous layer of many native wi Idflowers, ferns, etc.

Limited species diversity in herbaceous layer.

Herbaceous layer mostly invasive exotic (non-native) vines.

Thick layer of leaf litter with deep, rich soil.

Leaf litter thin; soil is eroded, poorly developed.


DUMPING AND LITTERING Impact on the Natural Landscape ~itter was observed throughout the Park, from the unsightly deposits of household and garden refuse along woodland edges adjacent to residential neighborhoods, to picnic litter left lying on the ground, or strewn about by animals rummaging in uncovered trash receptacles. Deposits of refuse have eliminated the herbaceous layer in some wooded sections, clogged streams, and attracted rodents and insects. The presence of trash constitutes a severe aesthetic and health problem in many areas.

Automobiles abandoned in remote areas after being stripped and burned constitute a unique problem. This latter situation was particularly noticeable in Tacony Park where over 20 automobile bodies were noted along .Tacony Creek. Recommendations for Controlling Litter A major campaign, probably on a city-wide basis, is needed to encourage people to clean up after themselves. Replacement of open trash receptacles with enclosed, animal-proof containers is recommended. Also needed are more trash containers, or perhaps dumpsters, in heavily used areas, and more frequent trash collection. With regard to the dumping of garden refuse in woodland edges, residents should be educated to realize the damage caused even by organic garden refuse. piles of garden debris smother native herbaceous species and are often the source of unwanted exotics. Neighborhood groups of Park supporters should be organized to discourage this and other abuses of adjacent parklands. The establishment of neighborhood composting centers, perhaps on park land where appropriate, might also be advisable. Police assistance is also needed to reduce the trash problem. All relevant anti-littering laws should be reviewed, updated if necessary, and strictly enforced.

23


INTERPRETATION OF THE NATURAL LANDSCAPE Introduction Nature centers can provide the necessary focus for community programs to teach the value of our natural lands and the ethics of their preservation. Although two nature centers now exist in Fairmount Park, for a variety of reasons they have not achieved their full potential. Staffing is inadequate, facilities limited, funding erratic, and communication with the Park Commission is poor. These factors are not conducive with the effective utilization of this valuable resource. The Fairmount Park Commission should realize that a nature center is a field station for the mobilization of the community to assist in the stewardship of the Park. Value to the Community and the Park Commission Increased respect for Park facilities - Through a variety of education and recreation programs organized by the nature centers, the public will become positively involved with the Parks. Activity of this type should help solve a myriad of problems caused by indifferent and hostile community members. Volunteers - Nature centers can serve as centers for the recruitment and organization of volunteers. Such problems should more than pay for themselves in volunteer hours for monitoring, maintenance and program development. Types of Programs Education - A major function of the nature center should be to serve as a resource for the schools. Nature centers should serve the schools by conducting teacher workshops and organizing outdoor and in school lessons and activities for student groups. Development of a curriculum built around the extensive natural and cultural resources present in Fairmount Park should be a high priority. This is a job for experienced professional educators and should be coordinated with the public schools. Community education programs with a wide range of content should be based on sound ecological theory, yet designed to attract people in varying age groups. The programs should not be defined strictly in preservationist terms. Thus a well attended program on hunting safety might be more valuable in fulfilling the long range management goals of the park, than a poorly attended program on hummingbirds.

24


Recreation - Environmental recreation should be a part of nature center activities. Cross country skiing, snow-shoeing (both on trails and in open areas), bird watching, orienteering, and many other activities can be structured so as to encourage respect for the environment. However, horseback riding should be strictly prohibited in nature education areas. The City is courting disaster by permitting horses to be ridden (sometimes at full gallop) on narrow, winding trails used by young school children on nature tours. Research - Ecological research related to habitat management, land use and the identification of existing flora, fauna and physical features are but a few of the many areas of study necessary for better resource management. Volunteers, under professional staff supervision, can carry out much of the necessary data collection. Local Environmental Problems - Nature centers can serve as information clearing houses on environmental matters. Further park/community cooperation could be engendered through the availability of nature center personnel to help solve local environmental problems. Recommendation A strong commitment should be made to establishing a system of nature centers throughout Fairmount Park~ However, because the Fairmount Park Commission does not have the inhouse expertise, we recommend that suitable contractual arrangements be sought with local educational institutions to provide the necessary professional services. A number of organizations, already active in this field, should be approached such as the Schuylkill Valley Nature Center, the Morris Arboretum, the Wissahickon Valley Watershed Association, and the Philadelphia Board of Education. The Park Commission should provide physical facilities and maintenance support for the nature centers as well as funding for staff and program development. Existing facilities include: the Pennypack Environmental Center which occupies a one story building on Verree Road in northeast Philadelphia. Adequate to carry out an environmental education program of moderate size, it includes a meeting room, offices, and restrooms. A network of nature trails has been established at the site. Located at the northern end of the Wissahickon Valley, the Andorra Natural Area includes some 200 acres of woods and fields with numerous trails. A small house on the property has been adapted to serve as a nature center, but sanitary facilities are inadequate and meeting space severely limited. Before improvements are made at Andorra a study should be undertaken to detetmine both the number and distribution of interpretive sites needed to best serve all parts of the City.

25


MANAGEMENT AND MAINTENANCE Types of Expertise Needed Staff - Skills needed to manage and maintain the natural landscape of Fairmount Park include resource managers, arborists, and road and trail repair crews. Consultants - Occasionally the Park requires additional skilled services such as those of a pathologist, entomologist, or professional forester. These services should be obtained as needed from such agencies as the Morris Arboretum of the University of Pennsylvania, Cooperative Extension Service, or the Pennsylvania Bureau of Forestry. Interpretive and educational programs might best be handled by contracting with an existing institution (public or private) which is in the business of providing such services. Equipment and Materials Maintenance operations need trucks, tractors, mowers, chainsaws, arborist equipment and miscellaneous tools. Scheduling of Management Programs and Maintenance Tasks All natural areas should be inspected by knowledgeable personnel twice a year and after severe storms to check for special management and maintenance problems. All contracted work should also be inspected by knowledgeable park personnel. A backlog of deferred maintenance exists in the form of dead and hazardous trees which should be removed (especially critical along Wissahickon Avenue at Carpenter's Woods). Once this backlog is taken care of a yearly program of removal of dead trees occurring along roads or trails should be instituted to reduce liability problems. Arborist work can be carried out throughout the year. Fields designated to be maintained as open areas should be mowed once a year in the late fall after a heavy frost has occurred. Trail maintenance can be done at any time of the year. Opportunities for Volunteer Action Volunteer groups could be an important adjunct to the paid staff. A variety of maintenance tasks and program activities could be undertaken provided staff leadership and facilities are available.

26


COST IMPLICATIONS Capital Budget Needs: Deferred Maintenance (tree removal s) Deferred Maintenance (bridge and trail repairs) Erosion Control Improvements Upgrade Andorra Nature Center Building Land Acquisition Cathedral Road area

300,000

$

300,000 1,000,000 500,000 ?

Annual Operating Budget Needs:* Educational Services Trail Maintenance Crew (4 men @ 15,000) Arborist Crew (4 men @ 15,000) Resource Managers (3)

200,000 60,000 60,000 60,000

*Park maintenance is handled on a district basis with no separation between natural areas and landscaped areas. The proportion of the total maintenance effort which could be assigned to natural areas varies with the district and is fairly low everywhere, except, perhaps, in the Wissahickon Valley.

27


~.

.,

APPENDIX A Happing Units for Natural Vegetation Types ~:

T 1.

2.

T Vegetation Structure

L ..!..

open

JL

glade

fores,t

Vegetation type with respect to moisture levels

! !!. F

!! T

xerophytes mesophytes periodic hydrophytes (flood pial" species) non-tidal hydrophytes (marsh, SWiIllP) tidal hyclrophytes (tidal marsh)

3. Size classes

forest

1 ! 1 !

DBH <'10 CIII 10 • 25C1l1

25 - 40 CIlI 40 ell

>

annuals perennials shrubs young trees

4·5. Characteristic species A - Ash B - Beech C - Mixed conifers D - Mixed decldous E - Box Ildlr F - Forbes G - GrlSse, H - H..lock I - Ananthus J - Japanese ho~suckle K• Wild black cherry L - Black locust M- Slack bl reh 6.

P - SYClIlOre Q - Ches ~ut oak R - Mixed maples S - $Issaf..as T - Tul1ptree U - BI ttersweet Y • Grape \I - Walnut X • Mixed exotics Y - llfllow Z - lIuttonbush

Percentage of exotics In herbaceous and shrub layers

1 ! 1 7.

N • Big-toothed aspen

o • Mbed oaks

0 - 101 10 - 501

>501

Percentage of exotics In understory and clnopy layers

1

0 - 101

!

10 - 50S

1

)501

28


APPENDIX A - 2

Explanation of Mapping Units for Natural Vegetation Types

Vegetation Structure Forest - Any area dominated by trees; the two areas that can produce confusion are glades and open areas with young trees. Glade - This term is used to describe areas of scattered trees with DBH greater than 10 cm, scattered in a generally open area; canopy cover is less than 70%; shrub layer is often missing. Open - Areas dominated by herbaceous species although, in many old field situations young trees and/or shrubs may be present in considerable numbers. Vegetational Type with Respect to Moisture Xerophytes - Plants that tolerate well-drained, sandy soils, that endure low moisture levels for extended periods of time; usually occur on or near ridge tops. Mesophytes - Plants of moderately well-drained to well-drained loamy soils, where moisture extremes are rare; generally found on mid and lower slopes of the stream valleys. Periodic hydrophytes - Plants that are tolerant of periodic inundation by seasonal flooding; found in low lying, flat areas bordering streams. Non-tidal hydrophytes - Plant species that can tolerate permanent (or occasionally semi-permanent) inundation by non-tidal water. Tidal hydrophytes - Plant species tolerant of twice-a-day inundation and exposure as the tide rises and falls; found in the zone between low and high tide along the Delaware River at the mouth of the Pennypack Creek.

29


Size Class Forest or Glade - Diameter of Breast Height (DBH) of the trees wnich form the largest percentage of the canopy. Open - refers to the dominant plant type. Characteristic Species Usually, but not always, the dominant species; those species which best typify the total plant community. Percentage of Exotics Percentage of total biomass occupied by species not native to Philadelphia County.

30

1983 Fairmount Park Natural Vegetation  

In order to evaluate the current condition of the natural vegetation of Fairmount Park and provide information needed for preparation of a m...

1983 Fairmount Park Natural Vegetation  

In order to evaluate the current condition of the natural vegetation of Fairmount Park and provide information needed for preparation of a m...