Floristic Quality Assessment (FQA) is a tool used in the United States to assess an area's ecological integrity based on its plant

species composition Relative species abundance is a component of biodiversity and is a measure of how common or rare a species is relative to other species in a defined location or community.Hubbell, S. P. 2001. ''The unified neutral theory of biodiversity and biogeog ...

. Floristic Quality Assessment was originally developed in order to assess the likelihood that impacts to an area "would be irreversible or irretrievable...to make standard comparisons among various open land areas, to set conservation priorities, and to monitor site management or restoration efforts." The concept was developed by

Gerould Wilhelm Gerould S. Wilhelm (born 1948) is an American botanist and lichenologist. He is known as author of several floras of the Chicago Region and the development of the Floristic Quality Assessment methodology, a tool to assess the integrity of natura ...

in the 1970s in a report on the natural lands of

Kane County, Illinois Kane County is a County (United States), county in the U.S. state of Illinois. According to the 2020 United States census, 2020 census, it has a population of 516,522, making it the fifth-most populous county in Illinois. Its county seat is Gen ...

. In 1979 Wilhelm and Floyd Swink codified this "scoring system" for the 22-county Chicago Region.

Coefficient of conservatism

Each plant species in a region is assigned a coefficient of conservatism, also known as a C-value, ranging between 0 and 10. A plant species with a higher score (e.g. 10) has a ''lower'' tolerance to

environmental degradation Environment most often refers to: __NOTOC__ * Natural environment, referring respectively to all living and non-living things occurring naturally and the physical and biological factors along with their chemical interactions that affect an organism ...

such as

overgrazing Overgrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, game reserves, or nature ...

development Development or developing may refer to: Arts *Development (music), the process by which thematic material is reshaped * Photographic development *Filmmaking, development phase, including finance and budgeting * Development hell, when a proje ...

and therefore is naturally restricted to undisturbed, remnant habitats. Non-native plants are either assigned a C-value of 0 or are excluded from assessments. In the Chicago Region, 84% of the native plant species have a C-value of 4 or greater. Plants with a C-value of 4 or greater rarely naturally move from a remnant area to surrounding degraded land. For example, the federally

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

Dalea foliosa ''Dalea foliosa'', commonly called leafy prairie clover, is a species of flowering plant in the legume family (Fabaceae). It is an endangered species in the United States, where it occurs in three states: Illinois, Tennessee, and Alabama.USFWS''D ...

'' has a C-value of 10. C-values are assigned within specific ecological and geographic regions by botanical experts familiar with the species'

autecology Autecology is an approach in ecology that seeks to explain the distribution and abundance of species by studying interactions of individual organisms with their environments. An autecological approach differs from ecosystem ecology, community ecolo ...

within the respective regions. , there were more than 50 different FQA databases ranging from the

Gulf Coastal Plain The Gulf Coastal Plain extends around the Gulf of Mexico in the Southern United States and eastern Mexico. This coastal plain reaches from the Florida Panhandle, southwest Georgia (U.S. state), Georgia, the southern two-thirds of Alabama, over m ...

to western

Washington Washington most commonly refers to: * George Washington (1732–1799), the first president of the United States * Washington (state), a state in the Pacific Northwest of the United States * Washington, D.C., the capital of the United States ** A ...

, though most databases represented regions in the eastern and central United States and Canada. The mean C-value (

\bar

) is calculated based on an inventory of plants. An area with a native mean C-value of 3.5 or higher likely has "sufficient floristic quality to be of at least marginal natural area quality." Remnant natural areas with mean C-values of 4.0 or greater are unmitigable.

Floristic Quality Index

The Floristic Quality Index (FQI, or Rating Index according to Swink and Wilhelm) is calculated by multiplying the mean C value by the square root of the total number of species:

\bar\sqrt

For example, the FQI fo
Nelson Lake Marsh
was 78 in 1994 and that for Russell R. Kirt Prairie was about 30 in 1999.

References

{{Reflist, refs= {{cite book , last1=Wilhelm , first1=Gerould , last2=Rericha , first2=Laura , author-link2=Laura Rericha , date=2017 , title=Flora of the Chicago Region: A Floristic and Ecological Synthesis {{cite report , first1=Gerould , last1=Wilhelm , author-link1=Gerould Wilhelm , first2=Linda , last2=Masters , date=June 1995 , title=Floristic Quality Assessment in the Chicago Region and Application Computer Programs , publisher=The Morton Arboretum {{cite journal , last1=Freyman , first1=William A. , last2=Master , first2=Linda A. , last3=Packard , first3=Stephen , date=2016 , title=The Universal Floristic Quality Assessment (FQA) Calculator: an online tool for ecological assessment and monitoring , journal=Methods in Ecology and Evolution , volume=7 , issue= 3, pages=380–383 , doi=10.1111/2041-210X.12491 , bibcode=2016MEcEv...7..380F , doi-access=free {{cite journal , last1=Matthews , first1=Jeffrey W. , last2=Spyreas , first2=Greg , last3=Long , first3=Colleen M. , title=A null model test of Floristic Quality Assessment: Are plant species' Coefficients of Conservatism valid? , journal=Ecological Indicators , date=May 2015 , volume=52 , pages=1–7 , doi=10.1016/j.ecolind.2014.11.017, bibcode=2015EcInd..52....1M {{cite book , last1=Swink , first1=Floyd , last2=Wilhelm , first2=Gerould , date=1979 , title=Plants of the Chicago Region, 3rd Edition {{cite book , last1=Swink , first1=Floyd , author-link1=Floyd Swink , last2=Wilhelm , first2=Gerould , date=1994 , title=Plants of the Chicago Region, 4th Edition {{cite report , first1=Gerould S. , last1=Wilhelm , date=1977 , title=Ecological assessment of open land areas in Kane County, Illinois , publisher=Kane County Urban Development Division

External links

Universal FQA
Biodiversity Environmental conservation Community ecology Measurement of biodiversity Index numbers Summary statistics for categorical data