A Citizen's Guide to Biological Assessment of Wetlands: The Vegetation Index of Biological Integrity (IBI)

This guide provides the basic framework for trained citizens to monitor and assess the condition, or health, of depressional wetlands in Central Minnesota. The field sampling protocols and biological assessment criteria presented in this guide are based on similar work by professional wetland biologists at the Minnesota Pollution Control Agency (MPCA). The basic approach is to use standard sampling methods to gather wetland plant community data, evaluate the data using multiple plant metrics, and determine a wetland condition assessment. A metric is a measurement of a plant community characteristic that is known to change in a predictable way in response to varying degrees of human influence from undisturbed to extremely disturbed conditions. The combination of multiple metrics into a single composite index results in a robust and reliable indicator of wetland condition (Figure 1). The final result is called an Index of Biological Integrity or IBI.