Ecological dynamics

[Caveat: The vegetation information contained in this section and is only provisional, based on concepts, not yet validated with field work.*]

The vegetation groupings described in this section are based on the terrestrial ecological system classification and vegetation associations developed by NatureServe (Comer et al. 2003). Terrestrial ecological systems are specifically defined as a group of plant community types (associations) that tend to co-occur within landscapes with similar ecological processes, substrates, and/or environmental gradients. They are intended to provide a classification unit that is readily mappable, often from terrain and remote imagery, and readily identifiable by conservation and resource managers in the field. A given system will typically manifest itself in a landscape at intermediate geographic scales of tens-to-thousands of hectares and will persist for 50 or more years. A vegetation association is a plant community that is much more specific to a given soil, geology, landform, climate, hydrology, and disturbance history. It is the basic unit for vegetation classification and recognized by the US National Vegetation Classification (FDGC 2008, USNVC 2017). Each association will be named by the diagnostic and often dominant species that occupy the different height strata (tree, shrub, and herb). Within the NatureServe Explorer database, ecological systems are numbered by a community Ecological System Code (CES) and individual vegetation associations are assigned an identification number called a Community Element Global Code (CEGL) (NatureServe 2019).

[*Caveat] The information presented is representative of very complex vegetation communities. Key indicator plants and ecological processes are described to help inform land management decisions. Plant communities will differ across the MLRA because of the naturally occurring variability in weather, soils, and geography. The reference plant community is not necessarily the management goal. The drafts of species lists are merely representative and are not botanical descriptions of all species occurring, or potentially occurring, on this site. They are not intended to cover every situation or the full range of conditions, species, and responses for the site.

This ecological site is characterized by a mix of xeric plant communities coinciding Northern Atlantic Coastal Plain Dune and Swale system (CES203.264). The prevailing ecological processes are due to maritime environment, including frequent salt spray, wind exposure, overwash, and sand movement. Other disturbances considered as threats include: development and fragmentation, barriers to connectivity to the open ocean, off-road vehicles, trampling, and invasive plants: Japanese black pine (Pinus thunbergii), Japanese sedge (Carex kobomugi), and common reed (Phragmites australis).

Plant community succession on the site coincides with coastal dune succession. Young, active foredunes, are nearest the ocean and are exposed to significant environmental stresses of onshore winds, high light intensity, high temperatures, and salt spray. Vegetation on the young dunes is a grassland community dominated by American beachgrass (ammophila breviligulata). Beachgrass plays a valuable role in jump starting succession and in stabilizing dunes. Beach pea is a common associate and can dominate at times (Sneddon et al. 2010). Other associated species includes American searocket (Cakile edentula), and seaside sandmat (Chamaesyce polygonifolia), pinweed (Lechea maritima), seabeach sedge (Carex silicea), coastal jointweed (Polygonella articulata), and seaside goldenrod (Solidago sempervirens). Northern bayberry (Morella pensylvanica), beach plum (Prunus maritima), and pitch pine (Pinus rigida) can occur sporadically within the grassland. Common exotic and invasive plants are Japanese black pine (Pinus thunbergii), beach rose (Rosa rugosa) and beach wormwood [dusty miller] (Artemisia stelleriana). The community is interspersed with small to large areas of bare sand. The active foredune communities coincides with Maritime Dune Community (Swain and Kearsley 2011) and Northern Beachgrass dune community (Sneddon et al. 2010). Northern bayberry dune shrublands (Sneddon et al. 2010) are a mid-seral community occurring on more stabilized dunes. Other shrubs include beach plum (Prunus maritima), Canadian serviceberry (Amelanchier canadensis), and occasionally, eastern baccharis (Baccharis halimifolia). American beachgrass (Ammophila breviligulata), wavy hairgrass (Deschampsia flexuosa) and seaside goldendrod (Solidago sempervirens) are interspersed among the shrubs. On older and more stabilized backdunes or secondary dunes, a pitch pine dune woodland (Sneddon et al. 2010) community will occur. This woodland community is dominated by pitch pine (Pinus rigida) with scattered black oak (Quercus velutina). Other trees include black cherry (Prunus serotina), red maple (Acer rubrum), and American Beech (Fagus grandifolia). The understory is can be very open with northern bayberry (Morella pensylvanica) and beach plum (Prunus maritima) (Sneddon et al. 2010). Woolly beachheather (Hudsonia tomentosa) and kinnikinnik (Arctostaphylos uva-ursi) are found in open areas. Herbaceous plants include starflower (Trientalis borealis), whorled yellow loosestrife (Lysimachia quadrifolia), wild sarsaparilla (Aralia nudicaulis), western brackenfern, and wavy hairgrass (Deschampsia flexuosa). Common vines include eastern poison ivy (Toxicodendron radicans), roundleaf greenbrier (Smilax rotundifolia), and Virginia creeper (Parthenocissus quinquefolia).