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C05 Hydromorphic Vegetation Class

Type Concept Sentence: Open freshwater and saltwater wetlands dominated by aquatic vegetation, either rooted with leaves rising up to or near the surface, or floating freely on the water surface. Stands typically have surface water, generally up to 2 m in depth, along ocean, lake, pond, and river margins in non-tidal, tidal and intertidal habitats.


Common (Translated Scientific) Name: Hydromorphic Vegetation Class

Colloquial Name: Aquatic Vegetation

Hierarchy Level:  Class

Type Concept: Hydromorphic growth forms dominate, including rooting and floating aquatic herbs and alga, in freshwater and saltwater wetland and open-water environments. Vegetation structure has irregular horizontal canopy spacing, and shoreline edges are shaped by natural processes. Emergent growth forms typically have <10% cover, and hydromorphic vegetation is at least 1% cover. Climates vary and are often less determinative than presence of open surface water conditions, which are typically found along ocean, lake, pond, and river margins in (semi-)permanently flooded non-tidal, tidal and intertidal habitats.

Diagnostic Characteristics: Hydromorphic growth forms dominate, including rooting and floating aquatic herbs and alga. Emergent growth forms have <10% cover, and hydromorphic vegetation is at least 1% cover. Vegetation structure has irregular horizontal canopy spacing, and shoreline edges are shaped by natural processes.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Open-water submerged and floating aquatic herb and alga wetland vegetation is included here if found in shallow aquatic habitats, usually <2 m in depth (e.g., along lakeshores and rivershores) and <8 ha in size (i.e., ponds), where active wave-forming or bedrock shoreline features are lacking (following the U.S. wetland classification criteria of Cowardin et al. 1979). Other deeper or larger aquatic habitats, such as lakes, rivers, estuaries and oceans, are included in the non-vegetated aquatic class, where the vegetation layer is no longer a controlling layer in the system. Submerged tidal aquatic vegetation has been mapped where cover is <10% (Orth et al. 2010).

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

Physiognomy and Structure: Growth Forms: Stands have hydromorphic growth forms, including rooted and floating aquatic herbs and alga, with various other growth forms.

Structure: Stands typically have surface water, up to 2 m in depth, and have aquatic herbs either rooted with leaves rising up to or near the surface or floating freely on the water surface, or alga. The vegetation cover varies from very open to closed, with irregular horizontal canopy spacing. Emergent growth forms have <10% cover, and hydromorphic vegetation is at least 1% cover. The height of the vegetation is a function of the water depth along the ocean, lake, river, or in the pond, but practically, only vegetation within 2 m of the water surface is included in this type.

Floristics: No Data Available

Dynamics:  No Data Available

Environmental Description:  Climate: Found in any climate where water regimes are sufficient to support rooted or floating vegetation. Soil/substrate/hydrology: This type includes shallow aquatic habitats, typically <2 m in depth (e.g., along ocean, lake and river shores) and <8 ha in size (i.e., ponds), where active wave-forming or bedrock shoreline features are lacking (Cowardin 1985). Other deeper or larger aquatic habitats, such as lakes, rivers, estuaries and oceans, are included in the non-vegetated Aquatic class, where the vegetation layer is no longer a controlling layer in the system.

Geographic Range: This type is found around the globe wherever open freshwater lakes, rivers and ponds are found.

Nations: No Data Available

States/Provinces:  No Data Available



Confidence Level: High

Confidence Level Comments: No Data Available

Grank: GNR

Greasons: No Data Available

Type Name Database Code Classification Code
Class 5 Aquatic Vegetation Class C05 5
Subclass 5.A Saltwater Aquatic Vegetation Subclass S09 5.A
Subclass 5.B Freshwater Aquatic Vegetation Subclass S13 5.B

Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available

Synonomy: < Coastal Mudflats and Brackish Waters (Rodwell et al. 2002)
< Freshwater Aquatic Vegetation (Rodwell et al. 2002)

Concept Author(s): Hierarchy Revisions Working Group, Federal Geographic Data Committee (Faber-Langendoen et al. 2014)

Author of Description: Hierarchy Revisions Working Group

Acknowledgements: No Data Available

Version Date: 10-17-14

  • Bailey, R. G. 1989. Explanatory supplement to ecoregions map of the continents. Environmental Conservation 16:307-309 with separate map at 1:30,000,000. USDA Forest Service, Washington, DC.
  • Cowardin, L. M., V. Carter, F. C. Golet, and E. T. LaRoe. 1979. Classification of wetlands and deepwater habitats of the United States. FWS/OBS-79/31. USDI Fish & Wildlife Service, Office of Biological Services, Washington, DC. 103 pp.
  • Faber-Langendoen, D., T. Keeler-Wolf, D. Meidinger, C. Josse, A. Weakley, D. Tart, G. Navarro, B. Hoagland, S. Ponomarenko, J.-P. Saucier, G. Fults, and E. Helmer. 2015c. Classification and description of world formation types. General Technical Report RMRS-GTR-000. USDA Forest Service, Rocky Mountain Research Station, Fort Collins, CO.
  • Orth, R. J., D. J. Wilcox, J. R. Whiting, L. S. Nagey, A. L. Owens, and A. K. Keene. 2010. 2009 distribution of submerged aquatic vegetation in Chesapeake and coastal bays. Special Scientific Report Number 152. Virginia Institute of Marine Sciences, College of William and Mary, Gloucester Point, VA. [http://www.vims.edu/bio/sav/sav09]
  • Rodwell, J. S., J. H. J. Schamineé, L. Mucian, S. Pignatti, J. Dring, and D. Moss. 2002. The diversity of European vegetation. An overview of phytosociological alliances and their relationships to EUNIS habitats. Report EC-LNV nr. 2002/054. National Reference Centre for Agriculture, Nature and Fisheries, Wageningen,The Netherlands.