Camp Edwards has a variety of natural communities, some unique to Cape Cod. In general the natural communities of Camp Edwards are often referred to as Pine Barrens. Camp Edwards has one of the few remaining stands of Pine Barrens in the Nation. It is the largest Pine Barrens system north of New Jersey.
Pitch pine/scrub oak barrens occur on deep, coarse, well-drained sands derived from glacial outwash, in the coastal plain, the Connecticut River Valley, and other scattered areas throughout the northeast. The sands are acidic, nutrient poor and drought prone. The low vegetation and sandy soils contribute to a tendency to be hotter than more mesic sites on summer days, with greater cooling at night, so have great temperature variations daily. The dry environment with low humidity contributes to the loss of heat at night, as in a desert. Exposure to the temperature variations may make plants more susceptible to other damaging factors such as insects or disease. In pitted outwash plains or rolling moraines, some low bowls, or kettles, are frost pockets and have more heath and lichen and less oak and pine. Deeper kettles may intersect the water table and have a Coastal Plain Pond at the bottom.
Pitch pine/scrub oak barrens are a fire maintained and fire dependent type of natural community: some of the component species depend on recurrent fires for their existence, and many of the species have volatile oils that actually encourage the spread of fires once they are ignited.
Development on Camp Edwards has historically included barracks, parade grounds, runways, and other facilities. As military activity at Camp Edwards decreased and facilities were abandoned and removed, this newly opened space has become forests and fields. At the same time, areas surrounding the base are developing at an alarming rate. As a result, Camp Edwards now represents an island of undeveloped land surrounded by a sea of development on Cape Cod.
An initial floristic survey of the JBCC identified 433 species of vascular plants (Jenkins 1994). Annual plant and rare plant surveys have identified an additional 124 specimens since 1994, increasing the total number of known plant species on Camp Edwards to 557. Data from the plant surveys originally indicated seven major plant communities on Camp Edwards. These communities were classified according to The Nature Conservancy's Albany Pine Bush Reserve Classification System: mixed woods forest, pitch pine-scrub oak forest, hardwood forest, scrub oak barrens, grasslands, wetlands, and disturbed communities. The natural communities of Camp Edwards and the JBCC in 2004 were reclassified using the Massachusetts Natural Heritage and Endangered Species Program's Natural Communities Classification (Swain and Keasley 2001). Some smaller undescribed plant communities, such as aspen ( Populus spp.) depressions also exist within the predominant natural communities.
The plant communities of Camp Edwards are generally classified as mid to late successional forest with intermittent early successional disturbed areas and kettle-hole ponds and wetlands. The climax plant community on Camp Edwards is likely an oak-pine forest with gray birch ( Betula populifolia ), American beech ( Fagus grandifolia ), and bitternut hickory ( Carya cordiformis ) (Foster and Motzkin 1999). Many of the plant communities at Camp Edwards have been influenced by several different factors including fire, ice storms, frost, drought, insect outbreaks, hurricanes, tropical storms, and historic logging and grazing. Natural or human induced fires have played an important role in creating and maintaining the plant communities on Camp Edwards.
The species diversity of the forests of Camp Edwards is generally quite low. On average, 53 species of plants were documented in each plant community of Camp Edwards, which when compared to most fertile woods of western New England that typically have up to 200 plant species, is relatively low (Jenkins 1994).
The following are brief descriptions of the Natural Communities of Camp Edwards as per the Classification of Natural Communities (Swain and Kearsely 2001):
Prior to the creation of the JBCC in the 1935, the area north of Wood Road was managed as pine, spruce, and fir plantations as part of Shawme State Forest. Areas were frequently burned over and planted with Austrian pine ( Pinus sylverstris ), white pine ( Pinus strobus ), red pine ( Pinus resinosa ), Spanish pine ( Pinus sp.?), Douglas fir ( Pseudotsuga menziesii ), balsam fir ( Abies balsamea ), Norway spruce ( Picea abies ), and larch ( Larix sp.) between 1925 and 1934 (US Department of Agriculture 1932).
Pitch Pine-Oak Forest Woodland:
The Pitch pine-oak forest woodland of Camp Edwards varies with degree of maturity. The structure of the forest ranges from a low canopy with a dense shrub layer to a taller canopy with a sparser shrub layer. In general, the plant community is in a mid-successional state where trees and shrubs are increasing in number, while forbs and grasses are becoming less abundant. The woodlands in the northern area of Camp Edwards tend to have a higher and denser canopy than the other forest communities. This may be due to less historic disturbance, resulting in a more mature forest.
The Pitch pine-oak forest woodland of Camp Edwards has a low canopy of pitch pine ( Pinus rigida ) and tree oaks (black oak ( Quercus velutina ), scarlet oak ( Q. coccinea ), and white oak ( Q. alba ) and a moderately continuous shrub layer of blueberry ( Vaccinium spp.), black huckleberry ( Gaylussacia baccata ), sheep laurel ( Kalmia angustifolia ), and scrub oak ( Q. ilicifolia ). The sparse forbe layer consists of braken fern ( Pteridium aquilinum ), wintergreen ( Gaultheria procumbens ), and Pennsylvania sedge ( Carex pensylvanica ), The low forest canopy, about 10-15 m tall, indicates a relatively young forest of no more than 100 years old.
Pitch Pine-Scrub Oak Community
In areas of forest from which hardwood trees were historically cleared, the plant community is almost entirely pitch pine ( Pinus rigida ) with an understory of sometimes very dense scrub oak ( Quercus ilicifolia ) (Jenkins 1994). Other tree species that are present but not common to the community are scotch pine ( Pinus sylvestris ), white oak, and scarlet oak. Scotch pine was likely introduced to Camp Edwards in the late 1920's and the early 1930's as plantations in Shawme State Forest (US Department of Agriculture 1932). The prevalent shrub species of Camp Edwards, black huckleberry ( Gaylussacia baccata ), blueberry (Vaccinium spp.) are commonly interspersed among scrub oak.
The structure of the pitch pine-scrub oak communities varies greatly with age. Younger stands are short, dense thickets of immature pitch pine. Immature pitch pine is relatively low in plant diversity and often occurs along roads, old firebreaks, or other previously disturbed areas, and comprises a total of 1% of Camp Edwards. The primary value of the immature pitch pine is habitat for prairie warblers. As the pitch pine matures, the forest has a more closed canopy, which ultimately out competes scrub oak for sunlight. However, in areas where pitch pine has been cleared, scrub oak often grows in extremely dense patches. In the pitch pine-scrub oak community, trees and shrubs in general are growing at a rate greater than in any other plant community, indicating a somewhat young, but rapidly maturing forest.
The diversity of the pitch pine-scrub oak community, 51 plant species, is about average for the plant communities of Camp Edwards. However, pitch pine and scrub oak are the dominant and most productive species in the community.
Black Oak-Scarlet Oak Forest/Woodland
Although pitch pine is the dominant tree species on Camp Edwards, some small stands of hardwood trees exist in the northeastern corner of the training area. Although the community comprises approximately 2% of Camp Edwards, it represents the most advanced state of succession of all of the plant communities. Oaks dominate the tree canopy of these stands and the shrub layer is similar to the pitch pine-mixed oak forest. The structure of the community varies with age from stands of immature hardwoods to more mature forest with a closed canopy and sparse understory.
Scrub Oak Shrubland
Much of Upper Cape Cod has been dominated by pitch pine and scrub oak barrens since the period of colonial settlement (Ruffner and Patterson 2000a). Thomas Bourne stated in 1769 that a large barren wilderness of small pitch pines and scrub oaks make up the space between the settlements [of Sandwich] and indeed the center and for the greater part of the township (Lovell 1984). The area was maintained in an early successional state as a result of timber harvesting and a catastrophic fire that occurred in 1772 (Sawyer 1988). Fire and frost effects typically suppress the growth of pitch pine and other tree species while promoting the growth of scrub oak. Fire scarring causes scrub oak acorns to germinate more readily and terminal buds to die, resulting in the growth of lateral branches. While frequent late spring frosts result in chronic dieback of developing leaves, slow growth rates, and reduced stem height which promotes shrub growth. Eventually, large herds of sheep were grazed throughout the Upper Cape, which limited tree growth and promoted the establishment of the scrub oak barren habitats.
The scrub oak shrubland covers 2,107 acres, or 15% of Camp Edwards, mostly within the Impact Area, but also in training areas C-13 and C-14, the firing ranges on the northern edge of the Impact Area, as well as surrounding Demo Area 1. This plant community represents one of the earliest states of vegetative succession on Camp Edwards and consists primarily of scrub oak ( Quercus ilicifolia ) with essentially no pitch pine ( Pinus rigida ). Other common plants in the scrub oak barrens include black huckleberry ( Gaylussacia baccata ), blueberry ( Vaccinium spp.), cat brier ( Smilax glauca ), and wintergreen ( Gaultheria procumbens ).
These are human created and maintained open communities dominated by grasses. Mowing is the typical maintenance, however on Camp Edwards fire has played and is playing a more important role.
There is a total of 1658 acres of cultural grasslands on the JBCC, only 175 acres of which are located on Camp Edwards (Figure 6-8). The remainder of the grasslands of the JBCC is located in the former parade grounds and the airfield on Otis ANG Base. Most of the grasslands of Camp Edwards are located in the cantonment area and were historically cleared for use as parade grounds during World War II. Other smaller patches of cultural grasslands exist in the 3600 Assembly Area north of Connery Avenue, adjacent to the wastewater treatment facility in the northwestern corner of the JBCC and the small arms firing ranges, although the afore mentioned areas are not managed grasslands.
The cultural grasslands are one of the least diverse plant communities on Camp Edwards, with only 37 identified species. The community is dominated by grass species including filiform fescue ( Festuca tenuifolia ), little bluestem ( Schizachyrium scoparium ), switchgrass ( Panicum virgatum ), hairgrass ( Deschampsia flexuosa ), redtop ( Agrostis gigantea ), poverty grass ( Danthonia spiccata ), and Pennsylvania sedge ( Carex pensylvanica ). The only common tree species is immature pitch pine and red cedar. Sweetfern ( Comptonia peregrina ) was found in dense thickets less than a meter in height, whereas bayberry ( Myrica pensylavanica ), blueberry, and scrub oak were present, but less common. Many non native species such as honeysuckle ( Lonicera spp.), Asiatic bittersweet ( Celastrus orbiculata ), autumn olive ( Elaeagnus umbellata ), and spotted knapweed ( Centaurea maculosa ) occur in the cultural grasslands of Camp Edwards and the JBCC. There are ongoing management efforts to to remove these exotic, invasive plant species.
The ponds and wetlands, which comprise only 55 acres, or.39%, of Camp Edwards, are the most diverse plant community (Figure 6-9). A total of 67 plant species were documented in the wetlands. There are six different types of wetlands based on the "Classification of Natural Communities in Massachusetts" (MA NHESP, 2001). They are Ponds, Coastal Plain Pond Shore, Kettlehole Level Bogs, Red Maple Swamps, Highbush Blueberry Thickets, and Woodland Vernal Pools. The following is a description of each.
The Coastal Plain Ponds of Camp Edwards are referred to as kettle ponds. Kettle ponds are typically deep ponds formed during the last Ice Age by large chunks of ice breaking off retreating glaciers resulting in depressions in the ground called "kettle holes." When the hole is deep enough to reach groundwater, it is then filled with water and is called a kettle pond. Seasonal changes in groundwater level are mirrored by changes in the level of these ponds. The fluctuating water levels alternately flood and expose the shore like a slow moving tide. This rates and depth of fluctuation is a main determinant of the plant types that can live in Coastal plain pond shore.
Coastal Plain Pond Shore
These are herbaceous communities of exposed pond shore. The ponds consist of shallow, acidic, exposed groundwater in the glacial outwash plain, with no inlet or outlet. Water levels rise and fall with changes in the water table. These changes can be quite dramatic and result in distinct Coastal Plain Pond flora.
In general, the Coastal Plain Pond Shore communities of Camp Edwards can be classified as having four concentric circular zones of vegetation. The first zone is the deepest area of the wetland where open water is present. This zone is often vegetated by floating plants including spotted bladderwort ( Utricularia purperea ), water shield ( Brasenia schreberi ), and water-lily ( Nymphaea odorata ). The presence of this vegetation depends entirely upon the water levels in these wetland communities.
The zone of emergent vegetation surrounds the open water zone and is located in the more shallow water of the wetlands. Common emergent plant species are usually grasses, including bur-reed ( Sparganium americanum ), wool grass ( Scirpus cyperinus ), and three-way sedge ( Dulichium arundinaceum ).
Beyond the shoreline of the wetlands lies a transitional zone that is occupied by many emergent species but is dominated by forbs. Lance-leaf violet ( Viola lanceolata ), northern bugleweed ( Lycopus uniflorus ), swamp candles ( Lysimachia terrestris ), beggar ticks ( Bidens frondosa ), hyssop-hedge-nettle ( Stachys hyssopifolia ), rush ( Juncus spp.), and sedges ( Carex spp.) are common throughout the forb zone.
As the wetland transitions into the surrounding forest community, a distinct shrub zone including highbush blueberry ( Vaccinium spp.), swamp azalea ( Rhododendron viscosum ), hardhack ( Spirea tomentosa ), inkberry ( Ilex verticillata ), leatherleaf ( Chamaedaphne calyculata ), swamp dewberry ( Rubus hispidus ), and goldenrod ( Solidago spp.) is present. Common tree species in this zone include red maple ( Acer rubrum ), pitch pine, and various oaks.
Although the four zones of vegetation can describe most wetlands of Camp Edwards, there are some exceptions. Monument Swamp, a Kettlehole Level Bog, is primarily a bog of sphagnum moss ( Sphagnum spp.) and cranberry ( Vaccinium macrocarpon ). In addition, many of the Woodland Vernal Pools, and Highbush Blueberry Thickets that lack standing water for much of the year do not have the distinct vegetation zones described above.
Kettle Hole Level Bogs
These bogs occur in kettle depressions, and have zoned vegetation. They are typically small, round, and lack inlets and outlets. Often the outermost ring is a wet moat that acts as a vernal pool when water remains for 2-3 months. They are surrounded by highbush blueberry ( Vaccinium corymbosum ) and swamp azalea ( Rhododendron viscosum ). The central mat has a mixture of members of the heath family.
Red Maple Swamps
Red Maple Swamps consist of 5% of the total wetlands on Camp Edwards. The hydrogeologic setting is the primary determinant of water regime and plant community in Red Maple Swamps. On Camp Edwards, they are seasonally flooded, fed by groundwater seepage, and overland flow. The Red Maple itself typically provides 90% of the canopy cover. The shrub layer is often dense and well developed and consist of Sweet pepperbush ( Clethra alnifolia ), swamp azalea ( Rhododendron viscosum ), and highbush blueberry ( Vaccinium corymbosum ). The herbaceous layer is highly variable with abundant ferns.
Highbush Blueberry Thicket
This natural community is characterized by acidic peat lands dominated by dense highbush blueberry ( Vaccinium corymbosum ) bushes and sphagnum hummocks. These tall thickets are generally flooded in the spring and early summer with water levels dropping below surface levels by late summer. Many examples are located in kettle holes.
Woodland Vernal Pools
Woodland vernal pools are small, shallow depressions with little or no vegetation within upland forests. They are temporally flooded, provide important breeding habitat for amphibians, and are typically isolated from other surface waters and are typically dry in the summer. They do not support fish populations. Vernal pools support diverse invertebrate and amphibian fauna that is not adapted to fish predation. Most wetlands on Camp Edwards are either vernal pools or function as one.
Disturbed Natural Communities
A major objective of the ITAM Program is to monitor and assess the effects of ARNG training on the natural resources of Camp Edwards. In order to achieve this objective, disturbed plant communities were surveyed to compare results to the native communities to determine the effect of land use on the flora of Camp Edwards. The disturbed plant communities of Camp Edwards were further divided into three subsets: bivouacs, burns, and other disturbed (e.g., areas mowed or subject to vehicle traffic).
The flora of bivouac sites, which total 395 acres or 2.7% of Camp Edwards, appear less diverse and more sparsely vegetated than the plant communities that surround them. In fact, bivouac sites have been found to have significantly fewer trees, lower shrub density, and less leaf litter than the surrounding habitats (Stokes and Griffin 1997). A P-value is a "probability value" relating to the probability that the groups being measured are statistically different from one another. A P-value of less than 0.05 indicates that there is less than a 5% chance that the differences observed are false. However, the plant diversity in the bivouacs, 52 species, was near average for the plant communities on Camp Edwards. The tree canopy in the bivouac sites is dominated by scarlet oak, black oak, and pitch pine. The under story in the bivouac sites is predominantly grasses, such as autumn bentgrass ( Agrostis perenans ), barnyard-grass (Echinochloa crusgalli ), and redtop, with interspersed shrubs, including black cherry ( Prunus serotina ), arrow wood ( Viburnum recognitum ), huckleberry ( Gaylussacia baccata ), and blueberry ( Vaccinium spp.). Within the bivouac sites, trees and forbsare decreasing in abundance, revealing a gradual trend of vegetative loss likely due to overuse of the areas.
Areas that were burned were one of the least diverse plant communities, with 40 documented species.
The purpose of prescribed burning on Camp Edwards is to manage for a particular community of plants, usually scrub oak barrens. The fast, low burning fires usually consume much of the forb layer and some of the shrub layer, but do not usually impact the tree canopy. As a result, many of the shrub and forb species of plants that recolonize the areas are not only early successional species, but also must be somewhat shade tolerant. Scarlet oak, black oak, white oak, and pitch pine are common tree species in the burn communities, with huckleberry, blueberry, and scrub oak dominating the shrub layer. Many of the early successional plant species such as winged sumac ( Rhus copallina ), wild indigo ( Baptista tinctoria ), sheep sorrel ( Rumex acetosella ), northern dewberry ( Rubus flagellaris ), sweetfern, gray birch, and poverty grass are generally more abundant in the burned plant communities than in any other community on Camp Edwards.
Although the other disturbed plant communities are considered negatively impacted, they are one of the most diverse communities on Camp Edwards with 63 documented species. Disturbance often prevents certain plant species from out competing other species, thereby promoting competition between species and increasing overall plant diversity. Grasses, including poverty grass, Pennsylvania sedge, little bluestem, cypress witchgrass ( Dichanthelium dichotomum ), hairgrass, panic grass ( Dichanthelium acuminatum ), and starved panic grass ( Dichanthelium depauperatum ), were the most prevalent plant form in the disturbed sites. However, pitch pine was abundant, with scarlet oak, black oak, white oak, and chinquapin oak ( Quercus prinoides ) being less common. The shrub layer, which included huckleberry, scrub oak, blueberry, and sweetfern, was typical of other plant communities on Camp Edwards. All plant forms, grasses, forbs, shrubs, and trees, have increased in abundance within the disturbed sites, indicating a gradual recolonization or succession of vegetation in these areas.
The plant communities that have been disturbed on Camp Edwards, either from training (e.g., bivouacs, vehicle traffic) or through land management (e.g., prescribed burning), often have characteristics that differ from the surrounding communities. Bivouacs are typically less diverse due to regular use, whereas the other disturbed areas were impacted over a shorter period of time, resulting in an increase in plant diversity. Bivouac restoration will serve to increase plant diversity and abundance within the bivouac sites on Camp Edwards. The burned areas are typically one of the least diverse plant communities, since prescribed fires promote growth of the shrubs and trees, but not the grass and forb layers. Therefore, disturbance may serve to maintain a particular natural community (i.e., prescribed burning in scrub oak shrublands) or increase plant diversity. However, where plant diversity is decreased as a direct result of training activities, such as in the bivouacs, land management activities (e.g., Bivouac Restoration) will be employed to restore plant diversity and abundance while maintaining the land for military training.
Some exotic and invasive plant species benefit from disturbance. They typically outcompete native species and proliferate in disturbed systems. One example of such a proliferation is that of Knapweed ( Centaurea maculosa ) in the Cantonment area. This species takes over areas where pipelines are put into the ground. The disturbance leaves the ground bare. The Knapweed quickly establishes and outcompetes native species. It should be noted however, that the Knapweed is slowly displaced by native grasses over a period of several years.
For citations see the Camp Edwards Integrated Natural Resource Management Plan.