Plant ecologists in Minnesota recently completed a classification of native plant communities using quantitative analysis of data from over 5,000 vegetation plots. The classification was developed both for biodiversity conservation work and forest resource management, an objective somewhat novel among vegetation classification efforts in North America. It is also one of the few plot-driven classifications in North America covering the full range of terrestrial and wetland vegetation across a broad region. Plant species data were analyzed using standard ordination and classification methods and indicator species analysis. Analyses of floristic data were supplemented with interpretation of soils data and other site data in delineating classification entities.
Results/Conclusions
The classification is hierarchical and has six levels. Among the upper levels is the ecological system, which groups plant communities according to influence by important ecological processes such as flooding or fire. Ecological systems are well suited for biodiversity conservation and forest resource mapping and planning at the landscape scale. Another important upper level, the floristic region, is based on geographic patterns of plant distribution that became apparent only after numerous rounds of analysis of plot data and development of lower levels of the classification. In some instances these patterns correlate strongly with paleo-vegetation patterns. The lowest levels of Minnesota’s classification are being applied to site-scale conservation and management activities, especially the native plant community class, a unit that correlates strongly with local gradients of moisture and nutrients for terrestrial communities and with water chemistry and water-level fluctuations for wetland communities. The Minnesota Department of Natural Resources has developed a series of tools for use of the classification, including field guides for identification and interpretation of plant communities, and forest management tools centered around native plant community classes.
