NEIWPCC banner

Water Quality | Wetlands | NEBAWWG

Northeast Regional Floristic Quality Assessment

forest image

The Floristic Quality Assessment (FQA) is a widely used method for ecological condition assessments in the United States. The foundation of the index is the conservatism concept, which estimates a species' ecological sensitivity or propensity to occur in areas least-altered by humans. Plant species are assigned coefficients of conservatism (CoC) where ruderal and exotic species receive the lowest scores, competitors and matrix species intermediate scores, and remnant-dependent species the highest scores. The method has spread to over half of the United States, but New York and New England have lacked CoC coverage. With funding from the Environmental Protection Agency and using some of the region's most experienced botanists, an effort was undertaken to assign CoC scores for the complete vascular flora of each New England state and New York State.

Botanists were asked to assign CoC according to this basic set of criteria:

0Non-native with a wide range of ecological tolerances. Often these are opportunistic invaders of intact undisturbed habitats.
1 to 2Native invasive or widespread native that is not typical of (or only marginally typical of) a particular plant community; tolerant of anthropogenic disturbance.
3 to 5Native with an intermediate range of ecological tolerances and may typify a stable native community, but may also persist under some anthropogenic disturbance.
6 to 8Native with a narrow range of ecological tolerances and typically associated with a stable community.
9 to 10Native with a narrow range of ecological tolerances, high fidelity to particular habitat conditions, and sensitive to anthropogenic disturbance.

In addition they were instructed to think about the statewide "average behavior" or ecological tolerance of each species. For purposes of floristic quality assessment, ecological tolerance is considered against disturbances and stressors occurring outside of the environmental variation to which the species is evolutionarily adapted. A species that needs periodic or annual disturbance (e.g., fire) may still be highly conservative (see Taft et al. 1997 for a detailed exposition of these concepts). Botanists were asked to select CoC using primarily their field experience and literature knowledge and without consulting other botanists. For each CoC, they assigned a personal confidence rating from 1 (low) to 5 (high).

The CoC lists for each state are available for download in excel format. Please note that revisions and updates to the lists are on-going in many of the states. *Contact Kimberly Roth for more information on how to obtain updated lists.* 


| Home | About Us | Contact Us | Back to Top | ©1997-2017 New England Interstate Water Pollution Control Commission; Connecticut, Maine, Massachusetts, New Hampshire, New York, Rhode Island, Vermont