Vegetation Databases and the Development of the National Vegetation Classification
Sunday, August 4, 2013: 8:00 AM-5:00 PM
University of Minnesota
Daniel S. Wovcha
Norman E. Aaseng
Scott R. Abella
The National Vegetation Classification (NVC) is an hierarchical classification system of all natural or semi-natural vegetation in the United States widely used by federal and state conservation agencies, NGOs, and practicing vegetation ecologists. The NVC is a process standard, as opposed to a content standard, and employs a peer-review system for development and modification. All proposed additions or modifications require the submission of a monograph with vegetation analyses on publicly available vegetation data. These data currently reside in a multitude of dispersed databases hosted by state and federal agencies, NGOs, and universities. In this workshop participants will learn the skills necessary to (1) query vegetation data from multiple sources, (2) reconcile the synonymy of species identifications in the data into a single commonly accepted system, (3) combine data from multiple strata or ecologically equivalent species, (4) reconcile and standardize environmental data, and (5) prepare the data for analysis in PC-Ord or R. Participants will work hands-on with multiple vegetation data sets selected for this exercise, and learn how to use R, Excel, or Access to reformat, reclassify, and structure the data into files suitable for analysis. We will address ecological issues of plot data quality, variable plot sizes, variability in taxonomic resolution, differing species abundance codes, different systems of landforms, topographic position, and soil properties, among others. Participants will leave the workshop with a full understanding of both the ecological and technical details necessary to work with publicly available data in support of the NVC.