Wetland Classification and Identification

Classification facilitates the management, restoration and protection of Colorado’s wetland resources by providing a common language about the types that exist, their functions and attributes, and relative frequency or rarity.

Several classification systems exist for wetlands in Colorado, each with a different focus. In concert with national classification effort led by NatureServe and the U.S. National Vegetation Classification System, CNHP has developed two classification systems wetlands based on vegetation and environmental setting.

  • Ecological Systems represent recurring groups of biological communities that are found in similar physical environments and are influenced by similar dynamic processes. As a mid-scale classification system, ecological systems are ideal for conservation assessment, inventory and mapping, land management, ecological monitoring, and species habitat modeling.
  • Plant Associations, or plant communities, are the finest scale of the U.S. National Vegetation Classification and are based on repeated patterns of species combinations.

In addition to classification systems, CNHP has also developed resources for identifying wetland plant species.

Beyond the work of CNHP, there are two widely used national wetland classification systems.

  • Cowardin Classification is used by the U.S. Fish and Wildlife Service through the National Wetlands Inventory (NWI) program wetland mapping. The Cowardin classification emphasizes physiognomy and water regime, but rarely includes detailed information on plant species.
  • Hydrogeomorphic (HGM) classification system is used by the U.S. Army Corps of Engineers and other agencies to assess wetland functions. The HGM classification system groups wetlands into seven different classes based on geomorphic position and hydrologic characteristics.