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Floristic Quality Assessment


During the growing season, conduct a Floristic Quality Assessment (FQA) as defined by Swink and Wilhelm and published in Plants of the Chicago Region, 1994.


Generate a list of observed plant species in the wetland areas.  This FQA method assigns to plant species a rating that reflects the fundamental conservatism that the species exhibits for natural habitats.  A native species that exhibits specific adaptations to a narrow spectrum of the environment is given a high rating.  Conversely, an introduced, ubiquitous species that exhibits adaptation to a broad spectrum of environmental variables is given a low rating.  Utilizing this method, a Floristic Quality Index (FQI) and Native Mean C are derived for a given area.  The FQI is an indication of native vegetative quality for an area: generally 1-19 indicates low vegetative quality; 20-35 indicates high vegetative quality and above 35 indicates “Natural Area” quality.  Wetlands with a FQI of 20 or greater are considered high quality aquatic resources.  The Native Mean C is also an indication of native vegetative quality.  Wetlands with Native Mean C values over 3.5 are considered high quality aquatic resources.  To ensure accuracy using this method, it is important that this list of plant species be generated within the growing season.



Swink, F. and G. Wilhelm. 1994. Plants of the Chicago Region, 4th ed. Indiana Academy of Science, Indianapolis. 921pp


Wilhelm, G. and L. Masters. 1999.  Floristic Quality Assessment and Computer Applications Version 1.0. Conservation Research Institute, Conservation Design Forum. Elmhurst, Illinois. December.


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Step 1 of the Section 7 Process


Section 7 Technical Assistance





Last updated: February 25, 2016