Page 1




April 1983





INTRODUCTION The George Lorimer Nature Preserve comprises 54 acres of fields, thickets,

hedgerows, woodlands, pond, and stream located in the Chester Valley in Tredyffrin Township.

The Preserve was given by Mr. and Mrs. Graeme

Lorimer in memory of their son'George to the Open Land Conservancy, a

private nonprofit organization committed to the protection of natural areas through acquisitions and conservation easements and to environmental education.

The draft master plan is designed to serve as a


guide to

managing the Preserve to effectively promote indigenous plant and wildlife communities, as well as provide the greatest opportunities for natural history observation, interpretation, and passive forms of outdoor recreation.

NATURAL AND CULTURAL HISTORY The Lorimer Preserve is underlain by Conestoga limestone, a relatively variable formation about 500 feet thick of cambrian and Ordovician limestone and dolomite which produces a more rolling topography than in areas underlain by more pure limestone.

The soils formed here are

in the Hagerstown and Conestoga series and are generally deep, well drained, and well suited to agriculture. ~re

Even moderate slopes, however,

very prone to erosion if cleared and are better suited to woodland

than crops. Prior to settlement by Europeans the landscape was dominated by forest with oak and chestnut in the upland and with beech and sugar maple favored on the more mesic soils. in pennsylvania's history.

The Chester Valley waS settled early

The soils yielded bountiful crops and,

unlike many neighboring areas, were circum-neutral in pH and did not

require liming, a procedure not developed until the late 19th century. The landscape of once unbroken forest was transformed to a mosaic of fields, farmsteads, and hedgerows, with small areas of second growth woodland relegated to land less suited to agriculture, such as floodplains and steep slopes.

In recent decades, however, agriculture has steadily

declined in importance in the area and has been replaced by rapid development and urbanization, a process which has continued to accelerate.

In Chester County, for example, over 10,000 acres were proposed for 1.

development in the last two years alone.

1'he Route 202 corridor has been

especially heavily impacted, and we may soon see such protected areas as the Lorimer Preserve as the only surviving relics of the heritage of the pastoral landscape.

RECENT LAND USE HISTCRY In 1946 Mr. and Mrs. Graeme Lorimer purchased the property, Magnet Stone Farm, where they reside today and which the Preserve was once a part of.

After World War II, the intensity of agricultural activities

was diminished locally and like many other farms the Lorimer land was used primarily for pasturage, while some areas were simply IIlet gall


EVentually, the whole landscape that is now the Preserve was

released from agricultural use, except for the mowing of paths and open fields, a management program which has to date been continued by the Open Land Conservancy. The present landscape of the Lorimer Preserve reflects both its natural history and the effects of past land use, especially grazing which has had the most noticeable impact on the vegetation communities of the Preserve.

Agricultural use of the landscape drastically simplifies the natural hapitats and communities which are generally confined to narrow corridors

and isolated patches of land.

In the case of cultivated land, continued

plowing and cropping limits native species to short-lived plants which might survive in the planted field, persistent rootstocks beneath the plow line, and accumulated ungerminated seeds in the soil.

In a grazed field no longer plowed annually, both nonnative imported pasture grasses and native volunteer herbaceous forbs and grasses can become well established.

Continuous trampling, however, prevents litter

buildup and tends to reduce the soil-holding capacity.

The tall long-

lived native grasses, such as Little Bluestem (Andropogon scoparius), tend to be favored by grazers and eventually may be replaced by sodforming grasses with a less easily cropped growth form.

With heavy

grazing pressure, one or two species of invaders, which are not well adapted to holding the soil and leave bare soil exposed I


t-end to become

Diversity is reduced and the thick dense thatch hinders


recolonization by native species.

The two invader s which became

predominant on the Lorimer property include the Japanese rose (Rosa multiflora) and Japanese honeysuckle (Lonicera japonica) , both of which are locally escaped from cultiva~ion.

The Japanese rose, for example,

was planted on this property and others throughout the region as a natural hedgerow to contain gra z ing stock and was recommended in farm

joucnals and by the U.S. Department of Agriculture and Soil Conservation Service until its range was very widespread.

The rose hips are .especially

favored by wildlife which spread the seed rapidly.

Furthermore, the

thorny stems are avoided by grazers which prefer other species, giving this plant an important competitive edge.

In some areas of the Preserve

the dense cover of rose and/or honeysuckle is so well established that the natural return to a native forest community will be delayed by decades. OTHER INVADERS Several other noteworthy exotic invaders which occur on the property

include Oriental bittersweet (Celastru s orbiculata) , a climbing, heaping vine which is not yet well established; Japanese silver grass (Miscanthus sinensis), a giant c lump grass which can be l ocally very invasive though not yet well established at Lorimer; Tree-of -Heaven (Ailanthus altissima) , which generally favors more urban conditions; Amur cork tree (Phellodendron amurense) , which never seems to become abundant, though naturalized individuals may be found throughout the region; and Norway maple (A cer platanoides) , which is presently extending its range most dramatically throughout the region at the expense of many native species.

The Norway maple is an extremely popular ornamental tree which has been p lanted extensively for centuries and has been naturalized just about as long.

Even undisturbed native habitats , which are generally most

resistent to invasion by aliens, have s hown signs of recent colonization

by Norway maple.

It is generally accep ted that Norway maple will

eventually comprise the predominant tree in our landscape.

The rapid

spread of the species is accompanied by a severe reduction in the extent and diversity of nativ e communiti es .

Norway maple exhibits a

strong inhibiting effect on th e native specie s through the dense and 3.

prolonged shade cast by the heavily foliaged canopy, accumulates chemical toxins in the soil and litter layer, and reproduces freely even in the shade of a' developed forest canopy,

The Norway maple often forms virtually

monospecific stands over bare so~l, presenting a sharp contrast to the

diverse patterns of the varied native habitats.

At present there is a

limited and localized invasion of Norway maple on the Lorimer property. However, the.numbers will undoubtedly increase .and present a very definite threat to the re-establishment of native communities on the site.


major points of entry on the preserve are the strip of land between the Turnpike and the Preserve where a mono specific Norway maple woodland has developed and from planted specimens, including a very large and cherished individual near where the small stream enters the Preserve.

It is the

Norway maple which may, if uncontrolled, shape the future landscapes of the Preserve as grazing shaped the present landscapes. LANDSCAPE TYPES The landscape types found on the Preserve today include: Lowland Woodland.

The only extensive woodland development in the

property occurs in the lowlands which were the first areas released from cultivation.

The trees are relatively even aged and walnut

(Juglans nigra) is predominant.

Japanese rose forms a nearly continuous

understory layer throughout and reproduction of native species is extremely limited. Late Woody Oldfield.

A large proportion of the more recently released

f ield s now support dense brushland growth ranging from native forest trees such as elm (Ulmus americana), hickories (Carya spp.), oaks (Qu ercus spp.) , box elder ' (Acer negundo) , red maple (Acer rubrum) , and native field species such as sassafras (Sassafras albidum) , black cherry (Prunu s serotina) , viburnums (Viburnum spp.) , red cedar (Juniperus virginiana), crabapples (Malus spp.) , red-osier dogwood (Cornus stolonifera) , and brambles (Rubus spp.).

Invader s , especially rose,

are well developed and range from abundant to nearly continuous in some

ar eas and include honeysuckle and Oriental bittersweet as well. Early Woody Oldfield.

in some areas herbaceous for bs , in particular

gold enrod (Soli dago spp .), still predominate though these places all


support some woody growth and will within a few years, unless managed, closely resemble the existing late woody oldfields. Rough Grass.

Two large rectangular fields as well as the paths are

currently ma i ntained as rough grass which is mown t hroughout the growing season.

Cover, however, is poorly established, and large patches of

honeysuckle mats (kept low growing by mowing) are established, and various lawn 'weeds such as foxtail (Setaria spp.) and plantains

(Plantago spp.) are abundant. Wetland Habitats -- Pond, Wet Meadow, and Stream Corridor.

A small stream

crosses the property and has been dammed to create a small pond and wet meadow edge.

At present the s l uice way is cracked and is being undermined

by the stream channel.

With the pond now drai ned , the bottom is exposed

and supports dense wet meadow vegetation , in particular sedges (Caren spp.) , rushes (Juncus spp . ) , nut sedges (Cyperis spp . ) , smartweeds (Polygonum spp. ) , and watercress (Nasturtium officinale). Current plans for this area include the repair of the water control structure which would re-establish water leve l s in the pond.

The stream

c orridor itself is quite narrow and often is not distinguished from the surrounding brushland.

Occasionally , however, wetland species have

become established , such as alder (Alnus spp.) which occurs at the pond and in sev eral plac es along the stream .

The most significant specimen

is a large black willow (Salix nigra) which occurs between the existing path and the upstream edge of the pond. Specimen and Hedgerow Trees.

Bec ause mo st of the landscape of the

Lorimer Per serve is relatively young, the larger s p ecimen trees and

large shrubs and native trees in the field s and in the hedgerows are especially important , both aesthetically and as seed sources.


include: l.

Young black oak


Shagbark hickories


Black willow


Large Norway map l e


Al der clump


Nannyberry viburnum


Bla c khaw viburnum



Young cherries and crabapples


Sassafras clump


Young black cherry hedgerow


Mature c herry hedgerow




Black ash

14 .

Red maple.




Sassafras hedgerow


Norway maple


Red maple




Sassafras c lump


Large alder


Red cedars

Other Features.

In 19B1 an access drive from North Valley Road and a

small graveled parking lot were developed .

The area is fenced and

provides vehicular access through a locked gate and pedestrian acc ess through a stile which controls the use of off-trail vehicles.

An entry

sign i dentifies the preserve and boundary signage has been post ed , although it is subject to frequent removal.





Lowland Woodland

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Late Woody Oldfield

Early Woody Oldfield

Rough Grass


Mown Path


Stream and Pond


Specimen and Hedgerow Trees








7. '-'-'-'-'-'

DIRECTIONS FOR THE FUTURE The wishes of the Lorimers and the goals of the Conservancy with regard to long-term planning for the Preserve are the same:

to establish a

diverse and healthy landscape which evokes the rich natural and cultural history of the site and brings this experience to the visitor.


landscape of the Preserve is both a gift to the future and a memorial to one who loved its fields and woodlands. In order to ensure the realization of these goals, three major directions

are proposed for the Preserve: 1.

The long-term Management Program of the Preserve should be directed toward favoring the diverse native habitats of the region as well as the pastoral landscape characteristic of the early settlement of the valley.


The development of the Visitor Program and facilities should foster an intimacy with nature.


The Conservancy should explore a variety of ways to protect the Preserve from adverse impacts while promoting a contiguous system

of protected lands throughout the county.


THE MANAGEMENT PROGRAM In a less heavily developed region, simply doing nothing except preserve the land would, over time, produce a rich variety of native habitats. However, with expanding populations of Norway maple nearby and the rapid disappearance of potential seed sources throughout the area, no such course of succession is likely.

Nearly all protected public land

in the region .is presently experiencing a decline ,in native species as

use and misuse increase both on-site and on adjacent lands.


less heavily trafficked than most parks, the Lorimer Preserve is nonetheless subject to similar stresses due to the surrounding


Today's understanding of ecology offers the opportunity to apply our knowledge of natural systems to the practical care of landscapes. Ecological management focuses on the relationship between plants and their habitat and seeks to work complementarily with natural processes. A variety of management techniques are available which have been demonstrated successfully.

However, because no two environments are

exactly the same, it is recommended that the Management Program begin incrementally, allowing sufficient time to observe the, results of each procedure.

The experimental sites also can serve as demonstration areas,

affording important educational opportunities in vegetation management and plant succession.

Such an approach will be more cost effective in

the long run and will enable the Conservancy to better budget their resources.

The basic techniques in the Management Handbook, which is appended to this report, include the familiar mechanical and chemical practices of weeding, mowing, fertilizers, and herbicides, as well as prescribed

burning which was more widespread in the past and was used locally by the Indians to maintain grasslands and a more open and wildlife-rich landscape than uniformly native forest, as well as to recycle nutrients in unharvested agricultural material. The Management Handbook is intended to initiate a program of land management which would be continuously updated to provide monitoring

of the methods used.

The management goals and guidelines are described


for each of the Preserve's landscape types. Plan)

(See Management

For each area at least two techniques have been recommended to

provide for more flexibility and experimentation. The long-range goal of vegetation management at the Preserve is to provide for diverse landscapes of varying ages in a pastoral setting of broad fields, hedgerows, forests, and oldfields.

Large expanses

where essentially no management is required have been identified and are intended to return gradually to upland forest.

The existing walnut

lowland would be managed to favor more species diversity, especially woodland wildflowers.

Those areas, presently designated as early

woody oldfields, would be maintained by mowing to arrest succession at this mid-phase while the rough grass meadows would be managed to favor tall native grasses and perennial wildflowers.

(See the Plan.)

It is important to remember that change in nature is most often gradual and continuous. the object.

A suddenly and dramatically altered landscape is not

Careful observation over several growing seasons is needed

to assess each practice and some patience is required. At the present time, the conservancy is arranging to have personnel

from the Natural Lands Trust carry out the Management Program.

Mr. Richard

Thompson from the Natural Lands Trust has walked the Preserve with Ms~

Toland and has reviewed the management guidelines with Andropogon.


WILDLIFE AND HABITAT MANAGEMENT The most severe problem facing wildlife today is loss of habitat.


current development pattern in the Chester Valley, which can be seen in industrial1office,and residential tracts, is often to leave no natural vegetation whatsoever on a site, except for a few lone "specimen" trees set in a sea of grass and asphalt, destroying wildlife

that persisted through centuries of agricultural use. developer


The exceptional

homeowner who conserves native plant communities and

relic wild places is providing critically needed habitat.


it is the large-scale nature preserves and protected lands such as the Lorimer which make the most significant contribution to the long-term protection of wildlife.

Even though many of the animals

are but rarely seen, much of the impetus for land conservation comes

from those whose primary concern is wildlife. The major direction in planning at the Lorimer, as recommended, is to

foster a diversity of native habitats in order to favor the most diverse array of animals -- a kind of stationary ark.

While there is no direct

management of wildlife recommended, management of the plant communities will determine what vJildlife habitats are available. The present wildlife of the Chester Valley reflects its pastoral heritage and is dependent upon the rich mosaic of plant communities ranging from forest and brushland to hedgerow and oldfield meadow.


addition, wildlife is generally more abundant at ecotones -- that is the transition and directing place of two different landscape types such as the edge between a forest and a field.

Many species range

over several landscape types as well, requiring, for example, the

forest for shelter as well as the meadow for its abundant grazing material.

The value of a particular habitat to wildlife is immeasurably

increased if it is adjacent to other different habitats.

A brushy

hedgerow between two fields and adjacent to a flood plain forest is far richer in species than acre upon acre of brushland. Recent changes at Lorimer have been both beneficial and detrimental to wildlife.

The large increase in the amount of land that is left

wild greatly enlarges the area available for wildlife.

The trend,

however, for the rose and other disturbance species to take over will

gradually reduce available wildlife habitat.

As larger and larger 10-i

areas are dominated by one or two species rather than the complex natural communities to which more species are adapted, wildlife diversity will also diminish. The wildlife management goal at the Lorimer is twofold: 1.

To enlarge the area of the site devoted to natural habitats, in particular by replacing two large fields of mown grass with oldfield habitats.



enhance the natural habitat diversity of a site which is

becoming more uniform by arresting natural succession in places

to retain younger, more open landscapes and by accelerating succession elsewhere to favor old, more layered landscapes.

While the management program focuses entirely on the landscape, it has been designed throughout to favor the maximum wildlife values. The methods recommended have been selected for both their long-term and short-term impacts on the wildlife.

Fire, for example, is a

natural and cyclically occurring process in the landscape and is integral to the life of native plant and animal populations, bringing with it a tremendous renewal of natural resources. however, in the short-term seem devastating.

Wildfire can,

Prescribed burning, on

the other hand, is timed to have only minimal impact and the carefully controlled line of flame licks only inches off the ground, disturbing only the litter layer at a time when nearly all vulnerable wildlife is protected beneath the soil.

Mowing is reduced to no more than

Once annually and is limited to the onset of the dormant season when there are no further nesting activities and juveniles are mature.

Herbicide use is restricted to direct application to the vascular tissue of individual plants and an alternate, though more labor intensive, technique is also always suggested.

The management effort

begins small and in many places continues only until stable native communities are reestablished ..

The following is a list of species that are likely to be found in each of the landscape types if the management program is carried out. LOWLAND FOREST Birds:

robins, catbirds, cardinal, song sparrow, chickadee, tufted

titmouse, Louisiana water thrUSh, hummingbirds, cuckoos, prothonotary

warbler, Maryland yellow-throat, red-breasted chat lO-ii


grey squirrel, opossum, raccoon, white-tailed deer, rabbit,

white-footed mice Reptiles/Amphibians:

dusky salamander, northern two-lined salamander,

box turtle, queen snake, garter snake, ribbon snake, red-spotted newt,

American toad, spring peeper UPLAND FOREST Birds:

yellow-breasted chat, red-eyed vireo, red start towhees, chickadee,

cardinal, yellow-bellied sapsuckers, brown thrasher, catbird, wood thrush Mammals:

woodchuck, rabbit, short-tailed shrew, opossum, raccoon,

white-tailed deer ReptileS/Amphibians:

wood turtle, box turtle, black racers, Eastern

milk snake,copperhead, spotted salamander, wood frogs EARLY WOODY OLDFIELD WITH RED CEDAR, adjacent to forest and hedgerow Birds:

sparrow hawk, red-tailed hawk, owls, bobwhite, mourning dove,

nighthawk, chimney swift, purple martin, goldfinch, chipping sparrow, field sparrow, white-throated sparrow, bluebirds, catbirds, cedar waxwings, myrtle warbler, hermit thrush, brown thrasher, tree swallow,

flicker, yellow-bellied sapsucker, purple finch, starling, crow, blackbirds, turkey vulture, meadow lark Mammals:

rabbit, Eastern mole l meadow jumping mouse, meadow vole,

shrews, skunk, opossum, bats, white-tailed deer, woodchuck

POND AND WETLAND, in addition to the species found in the lowland forest Birds: Mammals:

wood duck, great blue heron, green heron, mallards, kingfisher muskrat, little brown bat


snapping turtle, spotted turtle, painted turtle,

northern water snake, bullfrog, leopard frog, pickeral frog HEDGEROWS and BRUSHY AREAS, in addition to those found in the early oldfields and upland forest if there is a mosaic of landscape types Birds:

blue jay, mocking bird, White-throated sparrow, ring-necked

pheasant, chestnut-sided warbler, myrtle warbler, white-eyed vireo, indigo bunting This projected species list was in part adapted from personal observation, road-kill data, and site investigation undertaken by Alice Richardson, Department of Landscape Architecture and Regional Planning, university of Pennsylvania.


THE VISITOR PROGRAM The Visitor Program is designed primarily to enhance the walker's experience of the landscape through a loop system of paths which bring the visitor to the varied environments of the Preserve.

Each path

becomes a journey along which the themes and habitats of the Preserve unfold.

The spaces of the journey vary from the intimate rOoms of a

forest to the.wide vistas across an open field. trips of varying length and difficulty.

The loops provide for

The existing paths have been

used wherever possible and a sequence of secondary paths which can be narrower and rougher are also identified.

(See the Plan.)

In addition to the vegetation management program, new plantings are recommended for the entry field and to enrich the visitor's introductory experience as well as at the pond to enhance the core of the Preserve as a memorial setting for pause and reflection.

The Entry Meadow From the first moment of arrival at the Preserve/ the visitor should be

immersed in the richness of the landscape.

At present the long empty

vista up the hillside delays this sense and focuses one's attention on

the neighboring property and the parking lot itself.

It is recommended

that the short rough grass be developed into a tall native grass and perennial wildflower meadow, dotted with a few islands of red cedar and flowering shrubs such as arrowwood (Viburnum dentatum) , nannyberry IV. lentago), chokeberry (Aronia arbutifolia) , and red-panicled dogwood (Cornus paniculata) as well as a grove of tulip poplars (Liriodendron tulipifera) to focus the distant views and add spatial interest to the journey.

(See the Management Handbook.)

The current facilities, which include a parking area, vehicular and

pedestrian access, and entry signage, should be complemented by a small brochure box at the stile which would eliminate the need for a sign or kiosk to inform the visitor of the do's and don'ts while providing a place for small tour maps and information on the Conservancy.

The fence

will soon be vine covered and honeysuckle, bittersweet, and other rampant exotics should be controlled in favor of the native vines such as woodbine (Parthenocissus quinquefolia) and trumpet vine'(Campsis




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~ Lowland Forest


Developing Upland Forest

I_ -:. :.::.:I

Tall Grass and wildflower Meadow


Rough Grass


Mown Path Rough Path

stream and Pond Specimen and Hedgerow . Trees

New Planting






Typical Red Cedar Island Planting in Entry Meadow Scale:




Red Cedar


. ~ e! .




6 Red Cedar (Juniperus virginiana) in varying sizes, ranging from 3' to S' in height, installed, balled, and bagged. 20 multistemmed shrubs, 3'-4' in height, installed, balled, and bagged; or bareroot (spring planting only) to be selected from the following species: Arrowwood (Viburnum dentatum) Nannyberry (Viburnum lentago) Chokeberry (Aronia arbutifolia) Red-panicled dogwood (Cornus paniculata) 1 1. .

Tulip Poplar Grove Planting in Entry Meadow

~~--~. Tulip Poplar

!['OUtline of Mulched Area

10 Tulip poplar (Liriodendron tulipifera) It is recommended that all the trees be planted at the same size, but this may range from 8' to 12' in height and may be installed as balled and bagged material or bareroot (spring planting only).





The Pond At present the approach to the pond is fairly abrupt, descending a steep portion of the trail which is actively eroding.

The path has been

lengthened to provide a gentle~ slope as well as a more indirect approach. Two simple wooden benches, one in the sun and the other in the shade, invite the walker to rest a while among the banks of winterberry (Ilex verticillata) and elderberry (Sambucus canadensis) planted at the water's edge.

A simple rock, serving as a memorial to George, was suggested by

Mrs. Lorimer to complete the setting. In the future more extensive restoration of the wetland habitats may be desired.


m ,

Planting and Benches i n Pond Area




Existing Walnuts

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~ Winterberry





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Existing willow



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winter berry



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2 Log Benches 25 Winterberry (Ilex verticillata) , may be p l anted as 3 ' -4 ,. tall bareroot material or balled and burlapped , 3 ' -6 ' (2 of the plants should be male, the rest female) 15 Elderberry (Sambucus canadensis), may be planted as 3 '-4 ' balled and bur lapped ma terial


bareroo t or


1"= 20 ' , ,;

THE PROTECTION PROGRAM The Chester County Open Land Conservancy is already active in establishing a comprehensive open space system locally.

The directions recommended

here to ensure the protection of .the Lorimer Preserve serve to reinforce the goals already addressed by the Conservancy.

The need to protect the

stream corridor and watershed area that drains to the Preserve will only increase in importance over time.

It is especially critical that

protected land areas be linked by adequate corridors to ensure rich biological connections, including providing necessary wildlife movement. The viewshed of the preserve is also fragile.

The adjacent broad fields

and hedgerows are essential to establishing the pastoral character, and the acquisition of additional land as well as easements should be encouraged.

Although the Conservancy is a small organization, it has already established several cooperative relationships with others that enlarge its capacities to meet its goals, such as coordinating management with

the Natural Lands Trust and its easement program with the Brandywine Conservancy.

Such cooperative efforts will be increasingly valuable in

the future, and it is recommended that a plan for a more comprehensive open space system be developed jointly by a confederation of local groups to better coordinate their efforts. At the smaller scale of more direct impacts to the Preserve, there are several issues which should be raised.

There has been limited dumping

at the edges of the property, largely of brushy debris, leaves, and grass clippings which should be cleared away.

If it is known who is

responsible, they should be asked to refrain from such activities in the future.

Large piles of decomposing vegetation invite colonization

by invaders, a circumstance already a problem at Lorimer.

A review of access points to the Preserve should be undertaken with the adjacent property owners.

In some cases additional access will be

appreciated and might provide a higher degree of control and monitoring than more anonymous entry points, such as along the Turnpike right-of-way. In other places it may be advisable to discourage access by limiting


mowing or moving the path slightly to establish a brushland barrier. If it is true that the mown paths adjacent to the Vanguard School are serving as access for hunters onto the Preserve, this matter should be resolved as soon as possible


undesirable useage becomes entrenched.


THE MANAGEMENT HANDBOOK This Management Handbook is intended to establish a monitored management program for the Lorimer Preserve.

It is recommended that a log, both

in writing and photographs, be kept of all management, possibly in loose leaf binder form.

A management map, showing the extent of area

of each recommended practice as well as first and second priority areas, has. been prep.ared for use with the handbook.

In addition, a mylar

reproducible of the aerial photograph at the scale of 1 inch to 100 feet is also available, from which prints can be made for recording site locations and boundaries. Only selected areas of the property have been recommended at this time although the whole program should be reviewed and re-evaluated on a periodic basis. The goal of the management recommended for the Lcrimer Preserve is not only to foster healthy native communities but to sustain landscape patterns that contain the unexpected, in lieu of the drastic simplification so characteristic of recent landscape management.

Both prescribed burning and limited and selective use of herbicides have been recommended.

It is expected that over time the intensity

of management required will steadily decrease, in sharp contrast to conventional methods, and that the use of herbicides can hopefully be limited to only an occasional outbreak of an otherwise difficult to control invader.

Fire, on the other hand, is a management tool that

may increase in usefulness and be gradually extended to include a wider area of the Preserve on a more infrequent burn cycle.

Because prescribed burning has been used very limitedly in Pennsylvania it is recommended that a variety of agencies be contacted to ensure the maximum exchange of information and the most satisfactory relationship with responsible agencies.

Locally, Les Hughes (644-1712), the Paoli

Fire Chief, and Maurice Hobaugh (469-6217), the District Forester in Pottstown, should be contacted.

Mr. Hobaugh has indicated he would be

interested in being present at any controlled burns and will be helpful in formulating procedure.

The State Fire Control Officer, Eugene

McNamara (717-787-2925), is not generally sympathetic to prescribed


burning, but would appreciate hearing of the results at Lorimer.


Garrepy (203-566-5348), the connecticut State Forester in Hartford, who has extensive experience with prescribed burni~g, has agreed to provide

us with any assistance or information that he can and has already contacted the individuals listed above. Before any burning is undertaken, the State Department of Environmental Resources must be contacted to obtain a special exemption for open burning in the southeast pennsylvania air basin.

The person to contact

for the necessary forms is: Dick Ruhl 1875 New Hope Street Norristown PA 19401 631-2415


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Norwav Maple or Aila ntQus '1'0 Be Removed

Source Area for

/--""./ ~-----






-- ..--------./

-. . . . -


Norway Maple













.--/ / ./ ..--./' / . /


Specimen and Hedgerow Tree,


Keep Clear of Vines Lowland Woodland Management Area , First Priority


Lowland Woodland Management Area , Second Priority


Early Woody Oldfield Management Area;lst Priority Early Woody Oldfield Management Area ,2nd Priority Phase Reduction in Rough Grass Mowing Cycle Rough Grass Management Area Fertilize and Close Crop Roug h Grass Management Area Prescribed Burn

New Path To Be Established


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,Norway Maple Control The effective control of Norway maple at the Preserve may be the single most important management effort toward conserving regional diversity. At the same time, it is understoqd that the two large specimens of Norway maple are quite valued and that neighboring properties will continue to serve as .seed sources.



recommended that a control program be undertaken immediately but

that the two specimens remain until such time as it is determined whether or not they can be controlled as sources of infestation.

A broad mow-

zone has been established around each specimen and along the Turnpike edge and the heavily contaminated hedgerow edge.

Elsewhere, a number

of Norway maple trees have been identified which should be removed. Norway maple is, however, difficult to control and an herbicide application is strongly recommended.

For larger trees, 3" caliper

and over, the notch and fill method is preferred which does not require cutting the tree down and involves breaking the bark by scattered axe cuts around the base of the tree and then saturating the inner bark with a concentrated solution of Round-Up. further information on safe procedure.) either in the dormant or growing season.

(See package directions for Such treatment may be undertaken A sudden die-back of top

fOliage will not occur nor is it desirable as the living aerial parts of the plant continue to exhaust the stressed root system.


reapplication may be necessary. For smaller plants, the stump may be cut and treated or the lower most foot of stems, and the root collar at the groundline may be soaked with herbicide if the tree is not cut down. In the event that it is decided to use no herbicides, control will be much more difficult, though is recommended nonetheless.


cutting of plants will be required as stump and root suckering occurs. Trees nearing seed producing size should be given first priority.

In addition to the official program of Norway maple control, a few dedicated individuals who pull Norway maple seedlings automatically while they walk the Preserve, as an avid gardener plucks spent blossoms, can make a world of difference.


The dark outsized foliage, flowers, and seedheads especially apparent in early spring; its late fall color; milky sap; and dun-colored bark; and opposite branching pattern all make the Norway maple extremely easy to identify and very vulnerable to this kind of persistent yet casual management if the larger individuals have been eliminated. In addition to the Norway maple, it is advised that the single observed Tree~of-Heaven be cut down.

require repeated cutting.

It is also prone to root suckering and may If an herbicide is used, a late summer

stump treatment of Round-Up is recommended. At all times it is important to be watchful for a sudden swelling of the ranks of an invader species.

A full-scale invasion can often be

avoided with swift action at the first surge.

Japanese silver grass

and Oriental bittersweet both bear watching on this site. run the most successful guardian against invader species

In the long

is the

establishment of diverse and healthy native communities on-site.


Lowland Woodland The most complex management issues are presented by the forest landscape. There are currently very few successful local examples of upgrading forest diversity while controlling aliens.

Despite seriously eroding

natural history values in many forested areas, there is limited action or experimentation.

Reliance upon herbicides is the major technique

and the useage is often broadcast and unnecessarily excessive to achieve the desired result.

The most promising practice, prescribed burning, is

not locally accepted and there is little practical experience within the state, despite increased useage and success elsewhere.

Although herbicides

and fossil fuel-powered equipment have become a way of life, fire offers an extremely energy-efficient and non-toxic alternative.

The present

fire protection policy has persisted for decades and was in part a response to devastating forest fires in the late 1800s in the northcentral United States when hundreds of lives were lost, largely as a result of high fuel accumulations of slash from extensive lumbering combined with a long period of drought. The walnut lowlands, the only forest type on the site, presently show almost no reproduction of any native species and are underlain for the

most part by dense cover of roses and/or honeysuckle.

Both species

require extremely high temperatures to effect root kill, a condition that is very unlikely on-site.

Therefore a combination of methods is

advised, including mowing and/or herbicides until the vine growth is controlled, at which time only limited prescribed burning is required. Once aliens are controlled, fire management will be used largely to maintain a richly diverse herbaceous layer within the lowland and to provide open views to the large pond. It is recommended that a brush hog or large rotary mower be used to cut down the top growth of the vines and flatten the brush to the ground. As there is virtually no reproduction of native woody species, only the invaders would be disturbed.

At this time, a stump spray with Ammate

(see package directions) is recommended although this step can be eliminated if no herbicide use is desired, understanding of course

that change will occur more slowly.

Ammate is a broad spectrum


herbicide and is not recommended for general use in the Preserve and should never under any circumstances be broadcast.

However, in

wetland environments Ammate does not get into the water and breaks up rapidly, less than two weeks.

A dormant season application is


If an herbicide is used, it may be advisable to wait one year before the first winter burn.

Otherwise a late winter burn to be initiated

on a cycle of one to three years is recommended.

Because the roses, etc.,

will continue to sprout, especially if unherbicided, annual mowing may be required until invaders are controlled.

Similarly, the burning will

encourage seedling development of both desirable and undesirable species, requiring nearly annual treatment until such time as honeysuckle and rose have been largely eliminated and a less frequent and more pulsed burn cycle can be implemented. In order to limit damage to existing trees, it may be advisable to wet the trunks close to the ground and/or pull litter and debris accumulations away from the root collar.

The most likely problem, however, is that

there will be insufficient fuel to achieve a good burn which may necessitate a slightly reduced burn cycle. A fire break is also required at the perimeter, and the old and new path loops in the large walnut lowland circumscribe an ideal first burn site. The lessons learned in the walnut lowland may also prove invaluable in later management of the developing forests of the Preserve.

Fire as a

management tool can efficiently maintain a constantly changing mosaic of vegetation types in lieu of more extended homogeneous landscapes. Perhaps most important, it has been suggested by Dr. William Overlease of West Chester State College, who has long tracked the rise and spread of Norway maple, that the reduction in frequency of ground fires may be the factor most responsible for its success in colonizing our native



Early Woody Oldfields In order to sustain a mosaic pattern of open and closed landscapes in the fabric of the preserve, it is recommended that succession be arrested in some places to retain an herbaceous meadow dotted with occasional

groves and thickets.

In large areas of what is now early woody oldfield

an annual mowing is recommended to control further woody growth.


rose and other invader development is sometimes dense a brush hog or large rotary. mower may be required at least the first year.

It is

further important that this cutting occur as soon as possible, preferably before spring and the roses and honeysuckle completely overtake the forbs such as golden rod.

The single annual mowing thereafter should

occur no earlier than late fall after several hard frosts and no later than early spring before the plants break dormancy.

OVer time as these

meadows develop more diversity, it may be worthwhile to alter the mowing schedule somewhat to favor selected species.


Rough Grass and Mown Paths The new path links should be established as soon as possible as it will only become more difficult over time as heavy brush develops.

An initial

cutting with a brush hog or large rotary mower will be required where woody growth is thick.

Once established however, the paths would be

managed as at present -- by frequent mowing during the growing season. It 路is recommended to retain the current arrangement with Mrs. Wilson for path mowing if possible. In the areas that are presently rough grass a reduced mowing cycle is recommended except in the two designated experimental areas.


with next season, a five-year program is suggested with five mowings the first year (spread evenly throughout the season), four mowings the second year, three mowings the third year, two mowings the fourth year, and one mowing annually thereafter.

The last mowing each year

and the single annual mowing should take place no sooner than late fall after several hard frosts and no later than early spring before dormancy is broken.

This cycle is designed to provide a gradual change to

conditions favorable for the growth of perennial wildflowers. In addition, two demonstration areas are suggested for experimenting

with alternatives to the mowing cycle.

In one the existing rough grass

would be fertilized and kept close cropped to establish a thick sod cover prior to release from frequent


In the second a prescribed

burning cycle of a controlled late winter ground fire annually at the outset, later reducing in frequency to no more than every three to five years, is recommended.

For the first burning it is recommended that

the grass be allowed to develop at least one foot of top growth to provide adequate fuel.

This procedure is expected to especially favor

little bluestern, a tall perennial grass, as well as 'legumes'.


late winter burn limits impact on wildlife and reduces the leaching of minerals by coinciding with the beginning of the period of most rapid growth.

The surrounding meadow should have been recently mown

to provide a fire break. be established.

If this is inadequate, a plowed break should

The local fire company should, of course, be alerted

and no burning should be undertaken in droughty or windy weather conditions.


New Plantings and Specimens All new plantings will require special care to keep them adequately watered for at least the first whole growing season and clear of heaping vines until well established.

A deep.soaking weekly is recommended from early

spring to late fall and should be considered part of the cost of installation.

In areas where weed control is expected to be difficult,

a temporary mulch of asphalt shingles or tar paper is quite an effective suppressant of competitive growth and can be completely disguised with leaf litter.

If deer browse is anticipated On tender new plantings, a

stack of unpalatable dead brush can be 'planted' with new material to discourage feeding. Upon completion of the new entry and pond plantings, additional planting should be continued to foster species diversity on site.

It is

recommended that the Conservancy's other land holdings might serve as a source of small, easily transplantable material which could be harvested with almost no disturbance to the collection site that might invite others to do the same.

Even the soil transported to the site with a

seedling represents an important contribution to the richness of the Preserve.

The designated specimens along the pathways should be kept clear of heaping vines and competitive growth.

(See Existing Conditions Map.)

Where the path mowing is not an adequate control mechanism, pulling off the vine and severing the root connection by removing a one-foot section of the vine's trunk near the ground will be generally adequate. Where additional control is desired, an application of Round-Up to the stump is recommended.










Lowland Woodland


Late Woody Oldfield


Rough Grass

~ Mown Path


Stream and Pond

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Profile for Andropogon Associates, Ltd

1983 George Lorimer Nature Preserve Draft Master Plan  

The draft master plan is designed to serve as a practical guide to managing the Preserve to effectively promote indigenous plant and wildlif...

1983 George Lorimer Nature Preserve Draft Master Plan  

The draft master plan is designed to serve as a practical guide to managing the Preserve to effectively promote indigenous plant and wildlif...