Floristic quality assessment as an indicator of human disturbance in forested wetlands of New Hampshire

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Bell, Jennifer-Lee
Across the country, degradation of freshwater wetlands has prompted a need for science-based methods for assessing and monitoring wetland condition. Floristic Quality Assessment (FQA) is an assessment that measures the health of an ecosystem. FQA is based on resilience values called Coefficients of Conservatism (C-values), pre-assigned to each plant species. The method has proven to signal human disturbance in most wetland types, but is unstudied in forested wetlands. I collected data from eleven Red Maple ���Sphagnum Basin Swamps to test the hypothesis that FQA signals human disturbance in forested wetlands of New Hampshire. I calculated four common indices of site Floristic Quality (Mean C, Cover Weighted Mean C, Floristic Quality Index, and Cover Weighted Floristic Quality Index) by strata and for all species in each 400 m2plot. I compared human disturbance proxies; Ecological Integrity Assessment (EIA) Scores (Level 2) and proportions of cleared land in contributing watersheds, to floristic quality indices using Spearman's test; Mean C (p= 0.04, rho=0.61) and Weighted Mean C (p=0.01, rho=0.71,) of all species were positively correlated with EIA scores. The Weighted Mean C of the herb layer (p=0.05, rho=0.61) was also positively correlated with EIA scores. Percentage of cleared land was also related to Weighted Mean C (p= 0.11, rho= -0.51). Overall, the Cover Weighted Mean C offered the most reliable metric for evaluating condition of forested wetlands, indicating a need for more intensive application and research in these systems.