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CEGL007151 Chamaecyparis thyoides / Magnolia virginiana - Cliftonia monophylla / Orontium aquaticum - Sphagnum spp. Swamp Forest

Type Concept Sentence: No Data Available

Common (Translated Scientific) Name: Atlantic White-cedar / Sweetbay - Buckwheat-tree / Goldenclub - Peatmoss species Swamp Forest

Colloquial Name: Gulf Coastal Plain Streamside Atlantic White-cedar Swamp Forest

Hierarchy Level:  Association

Type Concept: This association, of the East Gulf Coastal Plain of Florida, Alabama, and Mississippi, occurs along small blackwater or spring-fed streams not subject to much flooding or siltation. Soils may be acidic peats but are usually circumneutral sands or sands overlain by peat. Although soils are perennially moist-wet, in contrast to more northern cedar swamp forests, they are seldom, if ever, inundated. The sand and peat soils include Histosols (Saprists and Hemists); the pH may be circumneutral or slightly acidic. Fires are infrequent and less destructive than in the northern range of Chamaecyparis thyoides. Gap succession is more important in this community than post-fire regeneration and accounts for the mixed, uneven-aged stands. Lightning strikes are the main cause of mortality in mature white-cedar trees within the range of this association. This community is an uneven-aged mixed forest consisting of a Chamaecyparis thyoides canopy often overtopping the Magnolia virginiana - Cliftonia monophylla subcanopy. Other tree species which may be present include Pinus elliottii var. elliottii and Nyssa biflora. The shrub stratum (Clethra alnifolia, Cyrilla racemiflora, Ilex coriacea, Lyonia lucida) and herbaceous stratum (Orontium aquaticum, Mitchella repens, Drosera sp., Osmunda cinnamomea, Osmunda regalis var. spectabilis) are both well-developed. This community occurs in isolated populations in northeastern Florida and in more extensive but discontinuous stands along the northern Gulf coast from the central Florida Panhandle through Alabama to Mississippi. Some northeastern Florida examples may lack Cliftonia. Atlantic white-cedar communities are early-successional, but Chamaecyparis thyoides is a long-lived species (250+ years); gap regeneration is hypothesized to be the primary means of reproduction. The community often succeeds to itself following fire or other disturbance. In the absence of fire and adequate gap regeneration, Atlantic White-cedar forests may be replaced by bay forest.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Mississippi sites are on Mississippi Sandhill Crane National Wildlife Refuge and in Pearl River County. The more northern Chamaecyparis thyoides-dominated forests (Maine through the Carolinas) are generally even-aged, monospecific stands, rather than the uneven-aged, mixed stands of cedar, hardwoods, and other conifers typical of the more southern white cedar forests. This difference is apparently a result of fire history. Soil differences also exist between the southern and northern white-cedar forests (Landaal 1978, Clewell and Ward 1987).

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available

Floristics: This community is an uneven-aged mixed forest consisting of a Chamaecyparis thyoides canopy often overtopping the Magnolia virginiana - Cliftonia monophylla subcanopy. Other tree species which may be present include Pinus elliottii var. elliottii and Nyssa biflora. The shrub stratum (Clethra alnifolia, Cyrilla racemiflora, Ilex coriacea, Lyonia lucida) and herbaceous stratum (Orontium aquaticum, Mitchella repens, Drosera sp., Osmunda cinnamomea, Osmunda regalis var. spectabilis) are both well-developed. Chamaecyparis thyoides is not shade-tolerant, and seedlings require exposed peat, rotting logs or mossy hummocks on which to germinate (Landaal 1978, Clewell and Ward 1987). Northern disjuncts include Parnassia grandifolia, Chamaelirium luteum, Lindera benzoin, and Lobelia amoena. Species at or near their southernmost range limits include Alnus serrulata, Arnoglossum diversifolium, Eutrochium fistulosum (= Eupatorium fistulosum), Liriodendron tulipifera, and Pieris phillyreifolia. State endemics include Taxus floridana (FL), Vicia ocalensis (FL), and Salix floridana (FL/GA) (Clewell and Ward 1987, Allard et al. 1990).

Dynamics:  Fires are infrequent and less destructive than in the northern range of Chamaecyparis thyoides (Clewell and Ward 1987, Laderman 1989, Wiseman 1986). Gap succession is more important in this community than post-fire regeneration and accounts for the mixed, uneven-aged stands. Lightning strikes are the main cause of mortality in mature white-cedar trees within the range of this association. Atlantic white-cedar communities are early-successional. but Chamaecyparis thyoides is a long-lived species (250+ years); gap regeneration is hypothesized to be the primary means of reproduction. The community often succeeds to itself following fire or other disturbance. In the absence of fire and adequate gap regeneration, Atlantic white-cedar forests may be replaced by bay forest dominated by Magnolia virginiana, Persea palustris, and Gordonia lasianthus. This association is very susceptible to major disruptions in hydrology (Allard et al. 1990); rapid, prolonged change in water depth kills Chamaecyparis thyoides seedlings and stresses or kills mature specimens (Laderman 1989). Leaf litter and woody debris should not be too dense in order for the shade-intolerant Chamaecyparis thyoides seedlings to survive.
Environmental Description:  Soils may be acidic peats but are usually circumneutral sands or sands overlain by peat. Although soils are perennially moist-wet, in contrast to more northern cedar swamp forests, they are seldom if ever inundated (Clewell and Ward 1987). Soil types include Histosols, Saprists, and Hemists (Laderman 1989, Allard 1990). Soil pH is between 6.6 and 7.5 in peninsular Florida white-cedar forests; soils of the northern Gulf Coast are not associated with alkaline springs so the pH in this part of the range may be more acidic (Clewell and Ward 1987).
Geographic Range: This association is found in the East Gulf Coastal Plain of Florida, Alabama, and Mississippi.

Nations: US

States/Provinces:  AL, FL, MS


Confidence Level: Low - Poorly Documented

Confidence Level Comments: No Data Available
Grank: G2G3

Greasons: No Data Available
Type Name Database Code Classification Code
Class 1 Forest & Woodland Class C01 1
Subclass 1.B Temperate & Boreal Forest & Woodland Subclass S15 1.B
Formation 1.B.3 Temperate Flooded & Swamp Forest Formation F026 1.B.3
Division 1.B.3.Nb Southeastern North American Flooded & Swamp Forest Division D062 1.B.3.Nb
Macrogroup 1.B.3.Nb.3 Sweetbay - Swamp Bay - Pond Pine Swamp Forest Macrogroup M032 1.B.3.Nb.3
Group 1.B.3.Nb.3.a Sweetbay - Loblolly-bay - Pond Pine Swamp Forest Group G037 1.B.3.Nb.3.a
Alliance A0196 Atlantic White-cedar Swamp Forest Alliance A0196 1.B.3.Nb.3.a
Association CEGL007151 Atlantic White-cedar / Sweetbay - Buckwheat-tree / Goldenclub - Peatmoss species Swamp Forest CEGL007151 1.B.3.Nb.3.a
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: < Atlantic White-Cedar: 97 (Eyre 1980)
< IIA2b. Atlantic White Cedar Swamp Forest (Allard 1990)
< White cedar (Clewell and Ward 1987)
Concept Author(s): J.E. Mohan

Author of Description: J.E. Mohan

Acknowledgements: No Data Available

Version Date: 02-02-94
  • ALNHP [Alabama Natural Heritage Program]. 2018. Unpublished data on file. Alabama Natural Heritage Program, Auburn University.
  • Allard, D. J. 1990. Southeastern United States ecological community classification. Interim report, Version 1.2. The Nature Conservancy, Southeast Regional Office, Chapel Hill, NC. 96 pp.
  • Allard, D. J., K. M. Doyle, S. J. Landaal, and R. S. Martin. 1990. Community characterization abstracts for the southeastern United States. Unpublished manuscript. The Nature Conservancy, Southern Heritage Task Force, Chapel Hill, NC.
  • Clewell, A. F. 1971. The vegetation of the Apalachicola National Forest: An ecological perspective. Unpublished document. USDA Forest Service, Tallahassee, FL. 152 pp.
  • Clewell, A. F., and D. B. Ward. 1987. White cedar in Florida and along the northern Gulf Coast. Pages 69-81 in: A. D. Laderman, editor. Atlantic white cedar wetlands. Westview Press, Boulder, CO. 401 pp.
  • Eyre, F. H., editor. 1980. Forest cover types of the United States and Canada. Society of American Foresters, Washington, DC. 148 pp.
  • FNAI [Florida Natural Areas Inventory]. 2010a. Guide to the natural communities of Florida: 2010 edition. Florida Natural Areas Inventory, Tallahassee, FL. 228 pp. [https://fnai.org/naturalcommguide.cfm]
  • Frost, C. C., and L. J. Musselman. 1987. History and vegetation of the Blackwater Ecologic Preserve. Castanea 52:16-46.
  • Laderman, A. D. 1989. The ecology of the Atlantic white cedar wetlands: A community profile. USDI Fish and Wildlife Service. Biological Report 85(7.21). 114 pp.
  • Landaal, S. 1978. Plant successional trends in selected Dismal Swamp stands of Chamaecyparis thyoides (L.) BSP (Atlantic white cedar.) Unpublished report to USDI Fish & Wildlife Service, Great Dismal Swamp National Wildlife Refuge.
  • MSNHP [Mississippi Natural Heritage Program]. 2006. Ecological communities of Mississippi. Museum of Natural Science, Mississippi Department of Wildlife, Fisheries, and Parks, Jackson, MS. 9 pp.
  • Southeastern Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Durham, NC.
  • Wiseman, J. 1986. Mississippi Natural Heritage Program community classification. Second draft. Mississippi Department of Wildlife, Fisheries, and Parks, Museum of Natural Science, Natural Heritage Program, Jackson. 11 pp.