SIGNIFICANT HABITATS AND HABITAT COMPLEXES
OF THE NEW YORK BIGHT WATERSHED

Long Island Grasslands
COMPLEX #9

List of Species of Special Emphasis

Map

 

I. SITE NAME: Long Island Grasslands

 

II. SITE LOCATION: The remaining native grassland communities on Long Island are small, disjunct grasslands or habitats occurring as highly localized areas over the island. They include, from west to east: the Hempstead Plains in the town of Hempstead, Nassau County; grasslands near the south shore in Sayville (town of Islip) and Bellport (town of Brookhaven) in Suffolk County; two small maritime grasslands near the Shinnecock Bay and Peconic Bay shorelines in Southampton, Suffolk County; and a network of maritime grasslands on the Montauk Peninsula in East Hampton, Suffolk County.

TOWNS: Brookhaven, East Hampton, Hempstead, Islip, Southampton

COUNTIES: Nassau, Suffolk

STATE: New York

USGS 7.5 MIN QUADS: Bellport, NY (40072-78), Southampton, NY (40072-84), Sayville, NY (40073-61), Freeport, NY (40073-65), Montauk Point, NY (41071-18).

USGS 30x60 MIN QUADS: Long Island East, NY (40072-E1), Long Island West, NY-NJ(40073-E1), Block Island, RI-CT-NY-MA (41071-A1).

 

III. BOUNDARY DESCRIPTION AND JUSTIFICATION: The Hempstead Plains site is bounded by Meadowbrook State Parkway on the east, Hempstead Turnpike on the south, the Nassau County Coliseum complex on the west, and Nassau Community College on the north. The Sayville grasslands include the open space within the boundaries of the Federal Aviation Administration property north of the Long Island Railroad in Sayville. The Bellport site is a small area south of the Long Island Railroad tracks in North Bellport. The Shinnecock Hills grassland is south of the Shinnecock Hills Country Club on both sides of the Long Island railroad tracks in Southampton, and the Conscience Point grassland is within the Conscience Point National Wildlife Refuge boundary east of North Sea Road and west of North Sea Harbor in Southampton. The four maritime grasslands on Montauk are part of a system of maritime communities that includes the entire Montauk Peninsula east of Napeague Harbor. These sites are the last known remnants of native grassland communities on Long Island and support several federally listed, candidate, and regionally rare plants and insects. Although several of the areas are small and degraded, the occurrence of rare species and the need for their protection and restoration justify their inclusion here.

 

IV. OWNERSHIP/PROTECTION/RECOGNITION: These grasslands are in a mix of public and private ownerships. The Montauk grasslands occur in Montauk Downs State Park managed by the New York State Office of Parks, Recreation and Historic Preservation, in both the Lee Koppelman Nature Preserve and Montauk County Park owned and managed by Suffolk County, and in one private parcel. The northern remnant of the Hempstead Plains is leased by Nassau Community College and managed in cooperation with The Nature Conservancy; the southern remnant is owned and managed by the Nassau County Department of Recreation and Parks. The Sayville grasslands occur on land owned and maintained by the Federal Aviation Administration as a radio tower site; part of this site has been transferred to the U.S. Fish and Wildlife Service, and the rest will be transferred in the near future. The Conscience Point grasslands occur within the boundary of the Conscience Point National Wildlife Refuge managed by the U.S. Fish and Wildlife Service. Significant Coastal Fish and Wildlife Habitats recognized by the New York State Department of State include Hither Hills Uplands and Big and Little Reed Ponds. The New York State Natural Heritage Program, in conjunction with The Nature Conservancy, recognizes several Priority Sites for Biodiversity within the Long Island Grasslands habitat complex. These sites are listed here along with their biodiversity ranks: Bellport Avenue (B2 - very high biodiversity significance), Bellport Railroad (B2), Conscience Point (B2), Hempstead Plain Grassland (B2), Montauk Downs Grassland (B2), Napeague-Hither Hills (B2), Sayville Grasslands (B2), Shadmoor Ditch Plains (B2), Shinnecock Hills (B2), Big Reed Oyster Pond Complex (B3 - high biodiversity significance). Shinnecock Hills, Conscience Point, and Montauk Point are within The Nature Conservancy's Peconic Bioreserve, one of their "Last Great Places."

 

V. GENERAL AREA DESCRIPTION: This network of native grasslands occurs on the Coastal Plain of Long Island, which was formed from the deposition and reworking of glacial sediments from the most recent (Wisconsin) glacial advance. The grasslands represent relict fragments of what was once a more widespread community on Long Island and the outer islands of southern New England. The maritime grasslands on the South Fork of Long Island, including Shinnecock Hills, Conscience Point, and the Montauk sites, occur on the terminal moraine, while the western and central Long Island sites (Hempstead Plains, Bellport, and Sayville) occur on the gently sloping outwash plain, or sandplain, south of the terminal moraine.

On the Montauk Peninsula, a mosaic of maritime plant communities, particularly grassland, heathland, and shrubland communities, occurs on much of the peninsula and comprises what is collectively referred to as moorlands. These maritime communities occur on sandy, glacially derived soils and are under the influence of a maritime climate, characterized by moderate temperatures, long frost-free season, ocean winds, and salt spray. While these edaphic and climatic factors help maintain the open grasslands, another key element appears to be fire, much the same as in Midwestern prairie systems. Throughout precolonial and colonial times, this area was cleared by fire and grazing. The maritime grasslands are generally dominated by bunch-forming grasses such as little bluestem (Schizachyrium scoparium), common hairgrass (Deschampsia flexuosa), and poverty-grass (Danthonia spicata), often with low heath shrubs and reindeer moss (Cladonia rangiferina). The grasslands occur as small pockets in the Montauk moorlands, especially on hilltops. Maritime heathlands on the Montauk Peninsula are dominated by bearberry (Arctostaphylos uva-ursi), beach heather (Hudsonia tomentosa), blueberry (Vaccinium angustifolium), black huckleberry (Gaylussacia baccata), bayberry (Myrica pensylvanica), and beach plum (Prunus maritima); maritime shrublands include black cherry (Prunus serotina), sumac (Rhus glabra and R. copallinum), bayberry, arrow-wood (Viburnum dentatum var. lucidum), hawthorn (Crataegus spp.), beach plum, wild rose (Rosa spp.), catbrier (Smilax rotundifolia), and blackberry (Rubus spp.). The maritime grasslands at Shinnecock Hills and Conscience Point have a similar species composition.

Hempstead Plains is a tall sandplain grassland community similar in character to the maritime grasslands, but located beyond the influence of offshore winds and salt spray. The soils are fertile, well-drained, silty loams and loamy sands. As with the maritime grasslands, the Hempstead Plains grasslands evolved with and were maintained by fires, some undoubtedly set by native Americans and others ignited by thunderstorms, over the last several thousand years. Historically, this community was dominated by prairie-type grasses, including big bluestem (Andropogon gerardii), little bluestem, broom-sedge (Andropogon virginicus), Indian grass (Sorghastrum nutans), and switchgrass (Panicum virgatum). These species are certainly present in the current remnants, but are not always dominant. Other characteristic native herbaceous species include boneset (Eupatorium hyssopifolium), goldenrods (Solidago nemoralis and S. juncea), rush (Juncus greenei), butterfly weed (Asclepias tuberosa), birdsfoot violet (Viola pedata), bushclovers (Lespedeza capitata, L. hirta, and L. angustifolia), false indigo (Baptisia tinctoria), blue-eyed grass (Sisyrinchium arenicola), and blue curls (Trichostema dichotomum). Invasion by exotic weeds such as Chinese bushclover (Lespedeza cuneata) and mugwort (Artemesia vulgaris) and woody plants such as Russian and autumn olive (Eleagnus spp.), crabapple (Pyrus sp.), multiflora rose (Rosa multiflora), blackberry, Asiatic bittersweet (Celastrus orbiculata) is a problem. The Hempstead Plains once covered about 16,188 hectares (40,000 acres) (see map); only about 26 hectares (65 acres) remain today. These are in two remnants, an 8-hectare (19-acre) site (Hempstead Plains north) being actively managed by The Nature Conservancy, and a 19-hectare (46-acre) site (Hempstead Plains south) managed by the Nassau County Department of Recreation and Parks. Prescribed burning has been used since 1991 to reduce woody species, stimulate native species, especially sandplain gerardia, and suppress weedy species at Hempstead Plains north.

The Sayville grasslands is an area of pitch pine (Pinus rigida) and mixed oak (Quercus spp.) woods, with interspersed grasslands and cleared areas, around radio towers maintained by the Federal Aviation Administration. The grasslands are highly diverse and dominated by little bluestem, broom-sedge, false indigo, bushclovers (Lespedeza spp.), asters (Aster spp.), pinweeds (Lechea spp.), and flax (Linum spp.). The Bellport Railroad site is a disturbed grassland area between a railroad and a highway dominated by Indian grass and little bluestem.

 

VI. ECOLOGICAL SIGNIFICANCE/UNIQUENESS OF SITE: There are 30 species of special emphasis in the Long Island grasslands, incorporating 24 species of plants and including the following federally and state-listed species. (Living resources and their habitats are dynamic; therefore, the ecological significance and species information presented here may not be complete or up-to-date. State and federal environmental agencies [see Appendix III for office contacts] should be consulted for additional information.)

Federally listed endangered
sandplain gerardia (Agalinis acuta)

Federal species of concern(1)
New England blazing-star (Liatris scariosa var. novae-angliae [=L. borealis])
bushy rockrose (Helianthemum dumosum)
Nantucket juneberry (Amelanchier nantucketensis)

1Species of special concern listed here include former Category 2 candidates.

State-listed endangered
silvery aster (Aster concolor)

State-listed threatened
few-flowered nutrush (Scleria pauciflora var. caroliniana)
orange fringed orchid (Platanthera ciliaris)
tick-trefoil (Desmodium ciliare)
whorled mountain-mint (Pycnanthemum verticillatum var. verticillatum)
sandplain flax (Linum intercursum)
southern yellow flax (Linum medium var. texanum)
lance-leaved loosestrife (Lysimachia hybrida)

State-listed special concern animals
coastal barrens buckmoth (Hemileuca maia maia)

State-listed rare plants
Emmon's sedge (Carex albicans var. emmonsii)
grassleaf ladies'-tresses (Spiranthes vernalis)
green milkweed (Asclepias viridiflora)
slender pinweed (Lechea tenuifolia)
field-dodder (Cuscuta pentagona)
Stueve's or tall bushclover (Lespedeza stuevei)
pine barren gerardia (Agalinus virgata)

Maritime grasslands are "edge of the ice" communities that occur only on Long Island, Block Island, Martha's Vineyard, Nantucket, and Cape Cod on land formed from the terminal moraine of the Wisconsin glaciation. These communities on Montauk, at Shadmoor Ditch Plains, Montauk Downs, Big Reed Oyster Pond, and Hither Hills, provide essential habitat for a number of regionally and globally rare plant species, including two of only twelve known remaining populations of sandplain gerardia in the world. Nantucket juneberry is endemic to these sandplain communities and on Long Island occurs only on Montauk and the Shinnecock Hills. The only known extant population of silvery aster in New York occurs at Shinnecock Hills. Other rare plants found in the maritime grasslands/heathlands at Montauk, Shinnecock Hills, and/or Conscience Point include bushy rockrose, New England blazing-star, lance-leaved loosestrife, pine barren gerardia, Emmon's sedge, dwarf plantain (Plantago pusilla), whorled mountain-mint, grassleaf ladies'-tresses, fringed boneset (Eupatorium hyssopifolium var. lacinatum), sandplain flax, and orange fringed orchid. Rare insects associated with these maritime grasslands and heathlands include the coastal heathland cutworm (Abagrotis crumbi benjamini), a subspecies that appears to be endemic to the edge of the ice communities in southern New England and Long Island. The maritime moorlands of the Montauk Peninsula are regionally significant and noteworthy, not only for their uniqueness and restricted geographical occurrence, but also for their relatively pristine condition. A more complete discussion of the resources of the Montauk Peninsula is included in the Montauk Peninsula narrative.

The remnant Hempstead Plains are the only remaining example of this unique grassland community that historically was the largest sandplain grassland on the East Coast and is now the westernmost sandplain grassland between Cape Cod and New York City. The Hempstead Plains is considered a unique, globally imperiled (G1) community by The Nature Conservancy. Like the maritime grasslands, sandplain grasslands are closely associated with the edge of the ice, being restricted to outwash deposits south of the moraine. These communities are endemic to southern New England and Long Island. The Hempstead Plains support two natural populations of sandplain gerardia and one experimentally-introduced population. The two largest populations of sandplain gerardia on Long Island are at the Hempstead Plains and Sayville Grasslands. The Hempstead Plains also support the westernmost occurrence of the bushy rockrose and other regionally rare plant species including green milkweed, flax-leaf whitetop (Aster solidagineus), tick-trefoil, pine barren gerardia, midland sedge (Carex mesochorea), few-flowered nutrush, stargrass (Aletris farinosa), and slender beadgrass (Paspalum setaceum var. setaceum). The handmaid moth (Datana ranaceps) occurs at Hempstead Plains on its food plant, staggerbush (Lyonia mariana).

The Sayville Grasslands support a high species diversity, including sandplain gerardia, the southernmost known occurrence of New England blazing-star, and several other regionally rare species including flax-leaf whitetop, slender pinweed, Stueve's bush-clover, sandplain and southern yellow flax, few-flowered nutrush, stargrass, and grassleaf ladies'-tresses. Several rare insects occur in the grasslands and surrounding woodlands. Butterflies and moths occurring here that utilize scrub oak as a food plant include Edward's hairstreak (Satyrium edwardsii), Herodias underwing moth (Catocala herodias gerhardi) and, occasionally, the coastal barrens buckmoth. The frosted elfin (Incisalia irus) also occurs here on its food plant, false indigo. The Bellport Railroad site, although small and degraded, supports many of the same plant species, including sandplain gerardia and New England blazing-star. Another site in Bellport (Bellport Avenue site) supports a small population of sandplain gerardia, but is a marginal pine barrens grassland along a road.

These grasslands have supported, and could continue to support, nesting by several species of declining grassland birds, including grasshopper sparrow (Ammodramus savannarum) and upland sandpiper (Bartramia longicauda). Another rare bird species that feeds in some of these grasslands is northern harrier (Circus cyaneus).

 

VII. THREATS AND SPECIAL PROBLEMS: Loss of habitat due to development has already reduced the once extensive grasslands on Long Island to a perilously few and small remnants. Those parcels of grassland that are not presently protected continue to be threatened by development. Suppression of wildfires, essential to the maintenance of regionally important maritime and pineland communities, is resulting in vegetation changes and consequent loss of the characteristic biota of these remnant communities, including several rare plants dependent on fire. Grassland habitat is succeeding into shrublands, woodlands, and forests. Exotic species are a problem, particularly in disturbed areas and areas where fire has been suppressed. Herbicide use along railroads and roads can reduce or eliminate rare plant species and host plants for rare insect species. Illegal dumping has resulted in loss and degradation of habitat. Use of these areas by off-road vehicles and horses has resulted in trampling and destruction of rare species. Erosion from heavy use of bridle trails and spread of seeds of weedy exotic species in horse manure along bridle trails is also a threat at the Montauk sites.

 

VIII. CONSERVATION RECOMMENDATIONS: Those remaining native grasslands that are privately owned should be protected by acquisition, cooperative agreements, conservation easements, zoning restrictions or planning policies, or other options to ensure the long-term conservation and protection of these unique sites. Protected sites should be actively managed to maintain and expand the grassland communities. The primary management goal for the individual sites should be the perpetuation of Long Island's unique maritime and sandplain grassland communities and associated rare plants in which fire has historically played an important ecological role. Fire management plans need to be specifically developed and implemented utilizing the experience of such organizations as the U.S Fish and Wildlife Service (Long Island National Refuge Complex) and The Nature Conservancy in cooperation with state and county park resource managers and private landowners in the vicinity. Other management tools should be used to control the encroachment by exotics and woody vegetation. Agreements should be reached with Long Island Railroad, Federal Aviation Administration, golf courses, and other organizations responsible for the maintenance of grassland sites and adjacent areas to control herbicide use or other inappropriate management. The entire Sayville Grasslands site should be transferred to the U.S. Fish and Wildlife Service and maintained as a sandplain grassland. The Shadmoor Ditch Plains site should be purchased by the U.S. Fish and Wildlife Service and included in the Long Island National Wildlife Refuge Complex. A management agreement with the town of Brookhaven should be enacted to protect the sandplain gerardia population and surrounding buffer areas at the Bellport Avenue site, and easements should be sought with adjacent landowners. Illegal dumping and off-road vehicle use should be controlled through public outreach and enforcement activities.

These same activities can apply to other open space on Long Island occurring on the outwash sandplain, including parks, airports, closed landfills, corporate parks, golf courses, and cemeteries. Candidate sites should be surveyed to determine their potential for restoration to native grasslands. A public outreach and technical assistance effort should be undertaken by government agencies and conservation organizations to promote restoration and maintenance at these sites.

A comprehensive field survey and regional analysis of rare species populations, including endemics and near-endemics, and threats to edge of the ice communities from New York City to Cape Cod would be helpful in determining and protecting the most important remaining areas.

Long Island contains six of the twelve known extant sandplain gerardia populations; all protection, research, and management objectives of the recovery plan should be given high priority by federal, state, and local agencies and organizations on Long Island.

 

IX. REFERENCES:

Antenen, S., M. Jordan, K. Motivans, J.B. Washa, and R. Zaremba. 1994. Hempstead Plains fire management plan, Nassau County, Long Island, New York. The Nature Conservancy Long Island Chapter, Cold Spring Harbor, NY.

Antenen, S., M. Jordan, and P. Whan. 1994. Fire management plan: for restoration of maritime grassland in the Big Reed/Oyster Pond complex, Montauk Peninsula, Long Island, New York. The Nature Conservancy Long Island Chapter, Cold Spring Harbor, NY.

Cain, S.A., M. Nelson, and W. McLeon. 1937. Andropogenetum Hempsteadii: a Long Island grassland vegetation type. American Midland Naturalist 16:344-350.

Conrad, H.S. 1935. The plant associations of central Long Island, a study in descriptive sociology. American Midland Naturalist 16(4):433-515.

Grossman, H.D., K.L. Goodin, and C.L. Reuss (eds.). 1994. Rare plant communities of the conterminous United States: an initial survey. The Nature Conservancy, Arlington, VA. 620 p.

Harper, R.M. 1918. The vegetation of the Hempstead Plains. Bulletin of the Torrey Botanical Club 18:362-386.

Hessl, A. and S. Spackman. 1995. Effects of fire on threatened and endangered plants: an annotated bibliography. Information and technology report 2. U.S. Department of the Interior, National Biological Service, Washington, D.C.

Neidich, C. 1984. The Hempstead Plains: Long Island's vanishing prarie. Sanctuary. Summer 1984.

New York State Department of State. 1987. Significant coastal fish and wildlife habitats program. Habitat narratives for Hither Hills Uplands, Big and Little Reed Ponds, and Oyster Pond. New York State Department of State, Division of Coastal Resources and Waterfront Revitalization, Albany, NY.

Reschke, C. 1990. Ecological communities of New York State. New York Natural Hertitage Program, New York State Department of Environmental Conservation, Latham, NY.

Seyfert, W.G. 1973. A study of the Hempstead Plains, Long Island, New York, and its vascular flora. M.S. thesis, C.W. Post College, Long Island University, Greenvale, NY.

Sneddon, L. and K. Metzler. 1992. Eastern regional community classification, organizational hierarchy, and cross-reference to state heritage community classifications; October 1992 Edition, terrrestrial, palustrine, and estuarine systems. The Nature Conservancy, Eastern Heritage Task Force, Boston, MA.

Stalter, R. and E.E. Lamont. 1987. Vegetation of Hempstead Plains, Mitchell Field, Long Island, New York. Bulletin of the Torrey Botanical Club 114(3):330-335.

Stalter, R. 1981. Some ecological observations of Hempstead Plains, Long Island, New York. Proceedings of Northeast Weed Science Society 101-106.

The Nature Conservancy. Undated. Sandplains of the Massachusetts Islands.

U.S. Fish and Wildlife Service. 1989. Sandplain gerardia (Agalinus acuta) recovery plan. Region 5, Newton Corner, MA.

U.S. Fish and Wildlife Service. 1991. Northeast coastal areas study: significant coastal habitats of southern New England and portions of Long Island Sound, New York. Southern New England - Long Island Sound Coastal and Estuary Project, Charlestown, RI.

List of Species of Special Emphasis

Map

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