National Wetland Plant List Indicator Rating Definitions

Abstract

Abstract : For over two decades, the National List of Plant Species that Occur in Wetlands has served as the standard reference for plant species wetland indicator status ratings in the United States. In 2012 the list, now called the National Wetland Plant List, was updated and approved for use for various purposes by the U.S. Army Corps of Engineers (USACE), the U.S. Environmental Protection Agency (EPA), the U.S. Fish and Wildlife Service (FWS), and the USDA Natural Resources Conservation Service (NRCS). Prior to the update, wetland plant species were rated using five categories, based on percentages representing the frequency that a species occurs in a wetland. The updated list uses the same five categories but they are now defined based on qualitative ecological descriptions. Quantitative frequency categories are now used only for field-based studies designed to challenge a species wetland rating. This Technical Note presents the new definitions for the five wetland plant categories. A long version is intended to standardize the groups using wetland features to define the groups, and a short version is intended to be easy to use for everyday purposes.