Vegetation classification is important for biological conservation and resource management and for basic scientific research. These activities require that ecological units be defined and that their distributions on the landscape be known and understood. A standardized method of classifying vegetation is needed to solve management and ecological problems that vary in scale and cross jurisdictional boundaries.
The National Vegetation Classification (NVC) is a central organizing framework for documentation, inventory, monitoring, and study of vegetation in the United States. It was publically released in 2016 after decades of work. Currently, federal land managers are required to translate (crosswalk) local methods of classifying vegetation to the NVC to allow land managers to collaborate across ownership boundaries and manage and identify trends on a landscape. To crosswalk plots, landowners and managers must collect enough data to be able to map or inventory vegetation using the NVC. In addition to the classification system itself, partners developed a database for vegetation plots and a peer review system that allows for transparent and evidence-based changes to the NVC, which was set up as a dynamic classification.
The USNVC has written description for over 6000 concepts at the Association level (www.usnvc.org), the lowest level of an 8-level hierarchy. All levels have written descriptions for all concepts, and completely cover all known vegetation communities in the conterminous United States.
VegBank (www.vegbank.org) is the public database of record on which the NVC is based, consisting of (1) actual plot records used in classification development, (2) vegetation types recognized in the NVC, and (3) plant taxa records. VegBank currently holds over 100,000 plot records, of which over 91,000 have been classified.
Because the NVC is a dynamic classification, changes can be made to the classification in a formal peer review process. The Proceedings of the USNVC serve as an official record of any changes, and the reasoning and evidence behind those changes. To determine if adequate evidence exists for a change, proposals are submitted to a scientific review panel, and if peer review determines scientific validity, the change is made, the plots used to make the case are archived in VegBank, and a document detailing the evidence and the decision is published online as part of the Proceedings (http://188.8.131.52/~usnvcorg/proceedings/articles/57).