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CEGL006850 Taxodium distichum - Nyssa biflora - Fraxinus profunda / Peltandra virginica - (Bignonia capreolata) Tidal Forest

Type Concept Sentence: No Data Available


Common (Translated Scientific) Name: Bald-cypress - Swamp Tupelo - Pumpkin Ash / Green Arrow-arum - (Crossvine) Tidal Forest

Colloquial Name: Chesapeake Bay Tidal Bald-cypress - Swamp Tupelo Swamp Forest

Hierarchy Level:  Association

Type Concept: This tidal forest borders mid to upper portions of the Pocomoke River in Maryland, and the Pamunkey, Chickahominy, and Piankatank rivers in Virginia. Habitats are predominately freshwater (<0.5 ppt) and subject to periodic inundation by diurnal or irregular lunar tides. Stands are typically positioned on low floodplains forming a corridor between fringing tidal marshes and upland habitats. These tidal forests are structurally diverse and best characterized by moderately dense (60-80% cover) to dense (80-100% cover) overstory canopies composed of Taxodium distichum and Nyssa biflora. Taxodium distichum is strongly diagnostic of this type, frequently attaining high cover and constancy. The canopy may also include, in variable proportions, species such as Fraxinus profunda, Acer rubrum, and occasional individuals of Liquidambar styraciflua, Pinus taeda, and Chamaecyparis thyoides. Magnolia virginiana and Carpinus caroliniana are frequent in the understory as trees or tall shrubs. Shrub and herb diversity is exceptionally high within this community and similar in composition and structure to Fraxinus spp.-dominated tidal wetland types.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Classification of this type is supported by analysis of an 80-plot dataset of tidal forests in Maryland in which stands characterized by Taxodium distichum emerged as distinct. Mean species richness among plots assigned to this type (N=9 plots) is 46 taxa per 400 square meters. Calculated relative basal area of characteristic species are Nyssa biflora (37.7 m2/ha), Taxodium distichum (21.7% m2/ha), Fraxinus profunda (21.2% m2/ha), and Acer rubrum (11.4% m2/ha). Although low in cover and occurring in >50% of Taxodium distichum stands sampled, Bignonia capreolata was chosen as nominal based on high fidelity to this type. In Maryland, Bignonia capreolata has a limited distribution and is only known from the Pocomoke River drainage where it occurs in swamp habitats dominated by Taxodium distichum. Plot data from the Pamunkey, Chickahominy, and Piankatank (Dragon Swamp) rivers in Virginia closely align with data from Maryland and are nearly identical in species composition and landscape position.

Similar NVC Types: No Data Available
note: No Data Available

Physiognomy and Structure: No Data Available

Floristics: These structurally diverse tidal forests are best characterized by moderately dense (60-80% cover) to dense (80-100% cover) overstory canopies composed of Taxodium distichum and Nyssa biflora. Taxodium distichum is strongly diagnostic of this type, frequently attaining high cover and constancy. The canopy may also include, in variable proportions, species such as Fraxinus profunda (10-25%), Acer rubrum (10-25%), and occasional individuals of Liquidambar styraciflua, Pinus taeda, and Chamaecyparis thyoides. Magnolia virginiana and Carpinus caroliniana are frequent in the understory as trees or tall shrubs. Shrub diversity is exceptionally high within this community and similar in composition and structure to Fraxinus spp.-dominated tidal wetland types. The most constant species in the shrub stratum include Ilex verticillata, Ilex opaca, Clethra alnifolia, Rhododendron viscosum, and Vaccinium corymbosum. Other notable taxa within this stratum include Viburnum recognitum, Rosa palustris, Eubotrys racemosa (= Leucothoe racemosa), Carpinus caroliniana, Lindera benzoin, and Euonymus americanus. Lianas and herbaceous vines are also common and can be locally abundant within multiple strata, especially along forested edges and in light gaps caused by windthrow or other disturbances. The most consistent taxa include Toxicodendron radicans, Smilax rotundifolia, Parthenocissus quinquefolia, and Dioscorea villosa, while other less frequent taxa include Apios americana, Mikania scandens, Bignonia capreolata, Campsis radicans, Smilax laurifolia, Smilax walteri, Clematis virginiana, and Vitis labrusca. Non-native vine species such as Lonicera japonica and Clematis terniflora were reported from many stands and tend to abound in light gaps and on stand edges bordering the water''s edge. An exceptionally diverse herb layer is characteristic of this type and can be attributed to several factors, including hummock-and-hollow microtopography, species recruitment from adjacent habitats, and tidal frequency and duration. Regularly flooded hollows typically support flood-tolerant swamp species such as Impatiens capensis, Peltandra virginica, Polygonum arifolium, Iris versicolor, and Saururus cernuus. Hummocks, which are slightly elevated above normal high tides, provide habitat for less flood-tolerant species such as Arisaema triphyllum, Thalictrum pubescens (= Thalictrum polygamum), Viola cucullata, Cinna arundinacea, Cicuta maculata, Boehmeria cylindrica, Carex seorsa, Carex bromoides, Carex stricta, and ferns such as Osmunda regalis var. spectabilis, Osmunda cinnamomea, Woodwardia areolata, and Thelypteris palustris.

Dynamics:  No Data Available

Environmental Description:  These tidal forests border mid to upper portions of the Pocomoke River in Maryland, and the Pamunkey, Chickahominy, and Piankatank rivers in Virginia. Habitats are predominately freshwater (<0.5 ppt) and subject to periodic inundation by diurnal or irregular lunar tides. Stands are best developed on low floodplains forming a corridor between open tidal marshes and nontidal habitats further inland. On the Pocomoke River, this community primarily forms a large (>40 ha) continuous fringing stand. Smaller stands typically form physiognomically distinct pockets and points along tributaries. Microtopographic features include pronounced hummocks and hollows with numerous protruding cypress knees. Hollows are regularly inundated by tidal water, whereas hummocks are less frequently flooded, thus supporting the establishment of trees and mesophytic herbs. Soils are poorly drained, slightly acidic tidal muck consisting of variable amounts of silt, clay and fine sands mixed with root-rich peats.

Geographic Range: This association occurs in the Chesapeake Bay region of Maryland and Virginia.

Nations: US

States/Provinces:  MD, VA




Confidence Level: Low - Poorly Documented

Confidence Level Comments: No Data Available

Grank: G3

Greasons: No Data Available


Concept Lineage: The 4 plots used to describe this type were determined to be ecotonal. This association is repaced by CEGL006850.

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available

Synonomy: = Taxodium distichum - Nyssa biflora / Bignonia capreolata Tidal Forest (Harrison et al. 2004)

Concept Author(s): Harrison et al. (2004)

Author of Description: J.W. Harrison

Acknowledgements: No Data Available

Version Date: 12-02-11

  • Beaven, G. F., and H. J. Oosting. 1939. Pocomoke Swamp: A study of a cypress swamp on the eastern shore of Maryland. Bulletin of the Torrey Botanical Club 66:367-389.
  • Dennis, J. V. 1986. The bald cypress in the Chesapeake Bay region. Atlantic Naturalist 36:5-9.
  • Eastern Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boston, MA.
  • Fleming, G. P., K. D. Patterson, and K. Taverna. 2017. The natural communities of Virginia: A classification of ecological community groups and community types. Third approximation. Version 3.0. Virginia Department of Conservation and Recreation, Division of Natural Heritage, Richmond, VA. [http://www.dcr.virginia.gov/natural-heritage/natural-communities/]
  • Harrison, J. W. 2011. The natural communities of Maryland: 2011 working list of ecological community groups and community types. Unpublished report. Maryland Department of Natural Resources, Wildlife and Heritage Service, Natural Heritage Program, Annapolis. 33 pp.
  • Harrison, J. W., P. Stango, III, and M. C. Aguirre. 2004. Forested tidal wetland communities of Maryland''s eastern shore: Identification, assessment, and monitoring. Unpublished report submitted to the Environmental Protection Agency. Maryland Department of Natural Resources, Natural Heritage Program, Annapolis. 96 pp.
  • McAvoy, W., and K. Clancy. 1993. Characterization of Category I non-tidal wetland communities in Delaware: Bald cypress Taxodium distichum (L.) Richard and Atlantic white cedar Chamaecyparis thyoides (L.) BSP. Delaware Natural Heritage Inventory, Division of Parks and Recreation, Dover.