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C05 Hydromorphic Vegetation Class

The U.S. National
Vegetation Classification
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.
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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:
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:
CCL01 Agricultural & Developed Vegetation, note: "These cultural wetlands may have a vegetation structure that is regularly managed (e.g., rice paddies), the water levels may be regularly manipulated, or the shores of the wetland may be highly modified by concrete, berms, etc."
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:
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:
States/Provinces:
Omernik Ecoregions:
Plot Analysis Summary:
Confidence Level: High
Confidence Level Comments:
Grank: GNR
Greasons:
Name:Database Code:Classification Code:
Class 5 Aquatic Vegetation C05 5
Subclass 5.B Freshwater Aquatic Vegetation S13 5.B
Subclass 5.A Saltwater Aquatic Vegetation S09 5.A
Concept Lineage:
Predecessors:
Obsolete Names:
Obsolete Parents:
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:
Version Date: 17Oct2014
References:
  • 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. Schamine√©, 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.