An authoritative classification of the terrestrial ecological communities of the United States, naming and describing more than 4,000 community types. Up-to-date information is maintained on NatureServe Explorer.
- Grossman DH, Faber-Langendoen D, Weakley AS, Anderson M, Bourgeron P, Crawford R, Goodin K, Landaal S, Metzler K, Patterson K, Pyne M, Reid M, and Sneddon L. 1998. International classification of ecological communities: terrestrial vegetation of the United States. Volume I. The National Vegetation Classification System: development, status, and applications. The Nature Conservancy, Arlington, Virginia, USA.