OPS 3-5
History of the United States National Vegetation Classification System
The objective of any natural classification is not the classification itself, but a tool for stewardship and research. Intuitively, such baseline knowledge of what exists on the landscape aids management decisions, and hundreds of site-specific classifications exist. These specialized classifications use different methods to collect data, different criteria for classifying, and different criteria for describing classified units. The United States, therefore, developed the Federal Geographic Data Committee to come up with standards for classifying the Nation’s resources. To this end, several subcommittees were established to focus on specific resources, and the Vegetation Subcommittee was charged with 1) defining and adopting standards for vegetation data collection and analysis, 2) facilitating inter-agency collaboration and inter-agency product consistency, 3) fostering accuracy, consistency, and clarity in the classification, 4) establishing a national set of standards for classifying existing vegetation, 5) developing minimum metadata requirements, and 6) collaborating state, federal and international efforts. The Subcommittee was established in 1991 and subsequently developed partners with NatureServe and ESA’s Panel on Vegetation Classification (ESA Panel). We examine the history of the Partner’s efforts to develop standards and a dynamic vegetation classification for the United States. We also discuss the current state of this effort and future directions.
Results/Conclusions
The USNVC classification approach emerged out of efforts in the 1970s and 80s to establish global classification frameworks, including supporting broad-scale vegetation mapping. The hierarchy of the USNVC was originally developed from the physiognomically-based UNESCO hierarchy in 1997. Flaws of this system were worked out over the next decade. The Vegetation Subcommittee of the FGDC, along with partners NatureServe and ESA’s Panel, finalized the standards for vegetation classification in 2008, agreeing on an eight-level hierarchy and common terminology. The classification separated cultural (anthropogenically-controlled) from more natural vegetation and is dynamic. The partners have subsequently been building the USNVC using two main strategies. A top down approach is being taken by the Hierarchical Revisions Working Group that is writing descriptions for all concepts of the top four levels. In addition, the partners have developed review criteria for the lower levels that essentially follow the decades-long effort of state heritage scientists and NatureServe in their development of a national classification, especially at the lowest levels. Ultimately, the USNVC provides a baseline of existing vegetation that may be used to assess long-term changes throughout the US, but dynamic to incorporate changes in vegetation as well.