Guidelines for describing associations and alliances of the U.S. National Vegetation Classification

TitleGuidelines for describing associations and alliances of the U.S. National Vegetation Classification
Publication TypeMiscellaneous
Year of Publication2003
AuthorsJennings, MD, Loucks, O, Glenn-Lewin, D, Peet, R, Faber-Langendoen, D, Grossman, D, Damman, A, Barbour, M, Pfister, R, Walker, M, Talbot, S, Walker, J, Hartshorn, G, Waggoner, G, Abrams, M, Brown, D, Hill, A, Roberts, D, Tart, D, Rejmanek, M

The purpose of this document is to provide guidelines for describing and classifying plant associations and alliances as formally recognized units of vegetation within the U.S. National Vegetation Classification (NVC), a regional component of the International Vegetation Classification (NatureServe 2003). The guidelines are intended to be used by anyone proposing additions, deletions, or other changes to the named units of the NVC. By setting forth guidelines for field records, analysis, description, peer review, archiving, and dissemination, the Ecological Society of America’s Vegetation Classification Panel, in collaboration with the U.S. Federal Geographic Data Committee, NatureServe, the U.S. Geological Survey, and others, seeks to advance our common understanding of vegetation and improve our capability to sustain this resource. We begin by articulating the rationale for developing these guidelines and then briefly review the history and development of vegetation classification in the United States. The guidelines for floristic units of vegetation include definitions of the association and alliance concepts. This is followed by a description of the requirements for field plot records and the identification and classification of vegetation types. Guidelines for peer review of proposed additions and revisions of types are provided, as is a structure for data access and management. Since new knowledge and insight will inevitably lead to the need for improvements to the guidelines described here, this document has been written with the expectation that it will be revised with new versions produced as needed. Recommendations for revisions should be addressed to the Panel Chair, Vegetation Classification Panel, Ecological Society of America, Suite 400, 735 H St, NW, Washington, DC. Email contact information can be found at or contact the Ecological Society of America’s Science Program Office, 1707 H St, NW, Suite 400, Washington, DC 20006, Telephone: (202) 833-8773. The authors of this document work as volunteers in the service of the Ecological Society of America and the professional opinions expressed by them in this document are not necessarily those of the institutions that employ them.