Coastal Plain Atlantic White Cedar Swamp

Coastal Plain Atlantic White Cedar Swamp at Quogue Wetlands
Gregory J. Edinger

System
Palustrine
Subsystem
Forested Peatlands
State Protection
Not Listed
Not listed or protected by New York State.
Federal Protection
Not Listed
State Conservation Status Rank
S1
Critically Imperiled in New York - Especially vulnerable to disappearing from New York due to extreme rarity or other factors; typically 5 or fewer populations or locations in New York, very few individuals, very restricted range, very few remaining acres (or miles of stream), and/or very steep declines.
Global Conservation Status Rank
G3G4
Vulnerable globally, or Apparently Secure - At moderate risk of extinction, with relatively few populations or locations in the world, few individuals, and/or restricted range; or uncommon but not rare globally; may be rare in some parts of its range; possibly some cause for long-term concern due to declines or other factors. More information is needed to assign either G3 or G4.

Summary

Did you know?

Atlantic white cedar can only colonize open boggy areas because its seedlings do not grow well in the shade. Fires, storms, or logging, may repeatedly level such a forest, but this tree will return again and again. Indeed, without catastrophies to repeat the process of invasion, red maple and black gum will in turn, become invaders within the swamp. The red maple invasion has already begun, but it is a gradual process. The seedlings of Atlantic white cedar, like pitch pine, will eventually fail to grow in the deep shade. Still, only if there are several centuries without a disturbance (a rare thing in nature), will there be a complete change.

State Ranking Justification

There are very few occurrences of coastal plain Atlantic white cedar swamps statewide. A few documented occurrences have good viability and are protected on public land or private conservation land. This natural community is still declining somewhat due to threats related to development pressure and alteration to the natural hydrology. This community has declined from historical numbers likely correlated with past logging of white cedar and the conversion of swamps to commercial cranberry bogs that were subsequently abandoned.

Short-term Trends

Presently, there are several, small coastal plain Atlantic white cedar swamps mapped totaling just over 100 acres. The numbers seem to be declining for a variety of reasons. These wetlands are threatened by increased residential and commercial development, land clearing, alterations to the natural hydrology, and poor water quality.

Long-term Trends

The number and acreage of coastal plain Atlantic white cedar swamps have probably declined substantially from historical numbers due to the value of the timber and the conversion to commercial cranberry bogs (now abandoned). The total historical acreage is unknown but it was probably around 2000 acres.

Conservation and Management

Threats

Coastal plain Atlantic white cedar swamps are mainly threatened by increased residential and commercial development, land clearing, and alterations to the natural hydrology. Alterations to hydrology could include an increase in demand for freshwater lowering the water table, increase in urban-suburban run-off, ditching, draining, and impounding. Changes in the water table could also mean an intrusion of salt water into the swamp.

Conservation Strategies and Management Practices

Management of coastal plain Atlantic white cedar swamps includes restricting access and maintaining water levels, flow, and quality. Where practical, establish and maintain a natural wetland buffer to reduce storm-water, pollution, and nutrient run-off, while simultaneously capturing sediments before they reach the wetland. Buffer width should take into account the erodibility of the surrounding soils, slope steepness, and current land use. Wetlands protected under Article 24 are known as New York State "regulated" wetlands. The regulated area includes the wetlands themselves, as well as a protective buffer or "adjacent area" extending 100 feet landward of the wetland boundary (NYS DEC 1995). If possible, minimize the number and size of impervious surfaces in the surrounding landscape. Avoid habitat alteration within the wetland and surrounding landscape. For example, roads and trails should be routed around wetlands, and ideally not pass through the buffer area. If the wetland must be crossed, then bridges and boardwalks are preferred over filling. Restore past impacts, such as removing obsolete impoundments and ditches in order to restore the natural hydrology. Prevent the spread of invasive species into the wetland through appropriate direct management, and by minimizing potential dispersal corridors, such as roads.

Development and Mitigation Considerations

When considering road construction and other development activities minimize actions that will change what water carries and how water travels to this community, both on the surface and underground. Water traveling over-the-ground as run-off usually carries an abundance of silt, clay, and other particulates during (and often after) a construction project. While still suspended in the water, these particulates make it difficult for aquatic animals to find food. After settling to the bottom of the wetland, these particulates bury small plants and animals and alter the natural functions of the community in many other ways. Thus, road construction and development activities near this community type should strive to minimize particulate-laden run-off into this community. Water traveling on the ground or seeping through the ground also carries dissolved minerals and chemicals. Road salt, for example, is becoming an increasing problem both to natural communities and as a contaminant in household wells. Fertilizers, detergents, and other chemicals that increase the nutrient levels in wetlands cause algae blooms and eventually an oxygen-depleted environment where few animals can live. Herbicides and pesticides often travel far from where they are applied and have lasting effects on the quality of the natural community. So, road construction and other development activities should strive to consider: 1. how water moves through the ground, 2. the types of dissolved substances these development activities may release, and 3. how to minimize the potential for these dissolved substances to reach this natural community.

Inventory Needs

Inventory needs for this community type include more quantitative plot data on species composition and an inventories of all bryophytes (non-vascular plants such as mosses) and lepidoptera (butterflies and moths). More inventory is also needed to document the extent of this community type in New York.

Research Needs

Research is needed to fill information gaps about coastal plain Atlantic white cedar swamps, especially to advance our understanding of their classification, ecological processes (e.g., fire), hydrology, floristic variation, characteristic fauna, swamp development, and succession.

Rare Species

  • Bartonia paniculata ssp. paniculata (Green Screwstem) (guide)
  • Callophrys hesseli (Hessel's Hairstreak) (guide)
  • Carex collinsii (Collins' Sedge) (guide)
  • Chamaecyparis thyoides (Atlantic White Cedar) (guide)
  • Lithophane viridipallens (Pale Green Pinion Moth) (guide)
  • Nehalennia integricollis (Southern Sprite) (guide)
  • Protonotaria citrea (Prothonotary Warbler) (guide)
  • Viburnum nudum var. nudum (Southern Wild Raisin) (guide)

Range

New York State Distribution

Coastal plain Atlantic white cedar swamps are currently restricted to Long Island with a spotty distribution within the coastal lowlands in Suffolk County. The historical range of this natural community is restricted to the coastal lowlands in scattered wetlands on Long Island. This community type may also have been found on Staten Island (although we have no records).

Global Distribution

Coastal plain Atlantic white cedar swamps occur on the northeastern United States coastal plain and in areas with a coastal climate (generally within 25 miles of the ocean) from New Hampshire to Delaware. It occurs in poorly-drained depressions or basins generally overlaying sand and gravel deposits.

Best Places to See

  • Quogue Wildlife Refuge (Suffolk County)
  • Alewife Creek and Big Fresh Pond SCFWH (Suffolk County)

Identification Comments

General Description

A mixed swamp that occurs on organic soils (peat or muck) in poorly drained depressions. The dominant trees are Atlantic white cedar (Chamaecyparis thyoides) with over 50% of the canopy cover, red maple (Acer rubrum), Blackgum (Nyssa sylvatica) and pitch pine (Pinus rigida). The shrub layer is diverse and includes sweet pepperbush (Clethra alnifolia), highbush blueberry (Vaccinium corymbosum), swamp azalea (Rhododendron viscosum), inkberry (Ilex glabra), dangleberry (Gaylussacia frondosa), black huckleberry (G. baccata), sheep laurel (Kalmia angustifolia), and bayberry (Myrica pensylvanica). The herb layer contains peatland type species including pitcher plant (Sarracenia purpurea), sundews (Drosera intermedia, D. rotundifolia), bladderworts (Utricularia spp.) marsh St. John's-wort (Triadenum virginicum). The organic substrate usually consists of several species of peat moss (Sphagnum spp.).

Characters Most Useful for Identification

A conifer or mixed swamp that occurs on organic soils along streams and in poorly drained depressions of the coastal plain. Atlantic white cedar (Chamaecyparis thyoides) makes up over 50% of the canopy cover. Atlantic white cedar may also dominate the shrub layer along with sweet pepperbush (Clethra alnifolia), highbush blueberry (Vaccinium corymbosum), swamp azalea (Rhododendron viscosum), inkberry (Ilex glabra), dangleberry (Gaylussacia frondosa), black huckleberry (G. baccata), sheep laurel (Kalmia angustifolia), and bayberry (Myrica pensylvanica).

Elevation Range

Known examples of this community have been found at elevations between 10 feet and 10 feet.

Best Time to See

The best time to visit these swamps is probably in June and July when a plethera of distinctive plants are in bloom. Among the most showy include the fragrant white blossoms of sweet pepperbush and swamp azalea, and the attractive pink flowers of sheep laurel.

Coastal Plain Atlantic White Cedar Swamp Images

Classification

International Vegetation Classification Associations

This New York natural community encompasses all or part of the concept of the following International Vegetation Classification (IVC) natural community associations. These are often described at finer resolution than New York's natural communities. The IVC is developed and maintained by NatureServe.

  • Atlantic White-cedar / Inkberry - Swamp Azalea Swamp Forest (CEGL006188)

NatureServe Ecological Systems

This New York natural community falls into the following ecological system(s). Ecological systems are often described at a coarser resolution than New York's natural communities and tend to represent clusters of associations found in similar environments. The ecological systems project is developed and maintained by NatureServe.

  • Northern Atlantic Coastal Plain Basin Peat Swamp (CES203.522)

Characteristic Species

  • Trees > 5m

    • Acer rubrum var. rubrum (common red maple)
    • Chamaecyparis thyoides (Atlantic white cedar)
    • Nyssa sylvatica (black-gum, sour-gum)
    • Pinus rigida (pitch pine)
  • Shrubs < 2m

    • Aronia melanocarpa (black chokeberry)
    • Clethra alnifolia (coastal sweet-pepperbush)
    • Gaylussacia baccata (black huckleberry)
    • Gaylussacia frondosa (dangleberry)
    • Ilex glabra (inkberry)
    • Kalmia angustifolia var. angustifolia (sheep laurel, sheep-kill)
    • Morella caroliniensis (bayberry)
    • Rhododendron viscosum (swamp azalea)
    • Vaccinium corymbosum (highbush blueberry)
  • Herbs

    • Anchistea virginica (Virginia chain fern)
    • Carex striata (Walter's sedge)
    • Carex trisperma (three-fruited sedge)
    • Drosera intermedia (spatulate-leaved sundew)
    • Drosera rotundifolia (round-leaved sundew)
    • Gaultheria procumbens (wintergreen, teaberry)
    • Hypericum virginicum (Virginia marsh St. John's-wort)
    • Osmunda regalis var. spectabilis (royal fern)
    • Osmundastrum cinnamomeum var. cinnamomeum (cinnamon fern)
    • Sarracenia purpurea (purple pitcherplant)
    • Symplocarpus foetidus (skunk-cabbage)
    • Thelypteris palustris var. pubescens (marsh fern)
  • Nonvascular plants

    • Sphagnum spp.
  • Submerged aquatics

    • Utricularia spp.

Similar Ecological Communities

  • Inland Atlantic white cedar swamp (guide)
    A basin swamp dominated or co-dominated by Atlantic white cedar (Chamaecyparis thyoides) located inland from the Atlantic Coastal Plain. Several examples are located along the top of a small mountain ridge.
  • Red maple-blackgum swamp (guide)
    Red maple-blackgum swamps are poorly-drained depression wetlands featuring a canopy dominated by red maple and blackgum. Often there are hummock islands and hollows with standing water.
  • Red maple-tamarack peat swamp (guide)
    A swamp that occurs on organic soils (peat or muck) in poorly drained depressions. Dominant canopy trees include both conifers and deciduous species; red maple and tamarack are characteristic.

Vegetation

Trees > 5m
75%
Shrubs < 2m
50%
Herbs
60%
Nonvascular plants
80%

Percent cover

This figure helps visualize the structure and "look" or "feel" of a typical Coastal Plain Atlantic White Cedar Swamp. Each bar represents the amount of "coverage" for all the species growing at that height. Because layers overlap (shrubs may grow under trees, for example), the shaded regions can add up to more than 100%.

Additional Resources

References

Bicknell, Eugene P. 1908. The white cedar in western Long Island. Reprinted from Torreya 8(2):27-28.

Cowardin, L.M., V. Carter, F.C. Golet, and E.T. La Roe. 1979. Classification of wetlands and deepwater habitats of the United States. U.S. Fish and Wildlife Service. Washington, D.C. 131 pp.

Edinger, G. J., D. J. Evans, S. Gebauer, T. G. Howard, D. M. Hunt, and A. M. Olivero (editors). 2014. Ecological Communities of New York State. Second Edition. A revised and expanded edition of Carol Reschke’s Ecological Communities of New York State. New York Natural Heritage Program, New York State Department of Environmental Conservation, Albany, NY. https://www.nynhp.org/ecological-communities/

Edinger, Gregory J., D.J. Evans, Shane Gebauer, Timothy G. Howard, David M. Hunt, and Adele M. Olivero (editors). 2002. Ecological Communities of New York State. Second Edition. A revised and expanded edition of Carol Reschke's Ecological Communities of New York State. (Draft for review). New York Natural Heritage Program, New York State Department of Environmental Conservation. Albany, NY. 136 pp.

Ehrenfeld, Joan G. and John P. Schneider. 1991. Chamaecyparis thyoides wetlands and suburbanization: Effect on hydrology, water quality and plant community composition. J.of Applied Ecology 28:467-490.

Eyre, F.H., ed. 1980. Forest cover types of the United States and Canada. Society of American Foresters, Washington, D.C.

Laderman, A.D. 1987. Atlantic white cedar wetlands. Symposium, Oct. 9-11, 1984, Marine Biological Laboratory, Woods Hole, MA. Westview Press. Boulder, Co. 401 pp.

Laderman, A.D. 1989. The ecology of the Atlantic white cedar wetlands: A community profile. U.S. Fish Wildlife Serv. Biol. Rep. 85(7.21).

Laderman, Aimlee D. 1986. Atlantic white cedar wetlands flora. Freshwater wetlands and wildlife: University of Georgia., Symposium Abstracts.

Motzkin, G. 1990. Atlantic white cedar wetlands of Massachusetts. Final report submitted to Massachusetts Natural Heritage and Endangered Species Program. 110 pp.

Motzkin, G. 1991. Atlantic white cedar wetlands of Massachusetts. Massachusetts Agricultural Experiment Station, University of Massachusetts. Research Bulletin 731. 53 pp.

Motzkin, Glenn, W.A. Patterson III and N.E.R. Drake. 1993. Fire history and vegetation dynamnics of a Chamecyparis thyoides wetland on Cape Cod, Massachusetts. J. of Ecology (18) 3: 391-402.

NatureServe. 2009. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://www.natureserve.org/explorer. (Data last updated July 17, 2009)

New York Natural Heritage Program. 2024. New York Natural Heritage Program Databases. Albany, NY.

New York State Department of Environmental Conservation. 1995. Freshwater Wetlands: Delineation Manual. July 1995. New York State Department of Environmental Conservation. Division of Fish, Wildlife, and Marine Resources. Bureau of Habitat. Albany, NY.

Reschke, Carol. 1990. Ecological communities of New York State. New York Natural Heritage Program, New York State Department of Environmental Conservation. Latham, NY. 96 pp. plus xi.

Schroeder, James G. and M.A. Taras. 1985. Atlantic white cedar. An American wood. Forest Service, USDA Publication no. FS-225.

Zampella, Robert A., Kim J. Laidig, Richard G. Lathrop and John A. Bognar. 1999. Size class structure and hardwood recruitment in Atlantic white cedar swamps of the New Jersey pinelands. J.of Torrey Botanical Society 126(3): 268-275.

Links

About This Guide

Information for this guide was last updated on: December 12, 2023

Please cite this page as:
New York Natural Heritage Program. 2024. Online Conservation Guide for Coastal plain Atlantic white cedar swamp. Available from: https://guides.nynhp.org/coastal-plain-atlantic-white-cedar-swamp/. Accessed March 28, 2024.