TY - JOUR
T1 - Floristic quality assessment signals human disturbance over natural variability in a wetland system
AU - Bried, Jason T.
AU - Jog, Suneeti K.
AU - Matthews, Jeffrey Wayne
N1 - Funding Information:
We thank Amanda Dillon and Arianne Messerman for helping with vegetation surveys, and the many volunteers (especially Barb Hager and Grace Barber) who helped monitor water levels. We also thank the Albany Pine Bush Preserve Commission , t he Wilton Wildlife Preserve & Park , and The Nature Conservancy Eastern New York Chapter for site access and their interest in the project. The manuscript has benefitted greatly from the insightful criticism provided by several anonymous reviewers. Financial support was provided by the New York State Department of Environmental Conservation, Environmental Protection Fund.
PY - 2013
Y1 - 2013
N2 - A common concern regarding the popular Floristic Quality Assessment (FQA) method is whether the site floristic quality scores change with natural temporal and site-specific variability. The more ignored question is whether this background variability will confound the index of human disturbance. Using non-forested seasonal wetlands in the northeastern United States, we tested if two common indices of site floristic quality (FQAI, Mean CoC) provide clear signals of site condition relative to gradients of wetland area and surface water depth, and consistent signals across time of year (early vs. late growing season), geomorphic setting (connected vs. isolated), and vegetation community type (pine barrens vernal pond, wet sedge meadow, shrub swamp). Mean CoC is the coefficient of conservatism (a qualitative estimate of species' sensitivity to human disturbance) averaged across the native and exotic taxa observed at a given site, and FQAI is the traditional Floristic Quality Assessment Index where Mean CoC is multiplied by square root of taxa richness. The FQAI did not linearly correspond to the site condition gradient and thus it could not be evaluated. Mean CoC was clearly associated with site condition, with no interference from wetland area or water level (based on computer-intensive resampling of linear model fit). Mean CoC also varied consistently with site condition between the surveys, geomorphic settings, and community types (based on computer-intensive resampling of linear model slope). However, connected wetlands showed inherently greater Mean CoC than isolated wetlands, suggesting a comparison of floristic quality between these categories would not be prudent. Overall this study suggests that FQA in the form of Mean CoC may withstand natural variability in certain non-forested wetland systems. Instead of assuming FQA is overly sensitive to natural variability, we recommend further efforts to identify situations in which FQA is robust.
AB - A common concern regarding the popular Floristic Quality Assessment (FQA) method is whether the site floristic quality scores change with natural temporal and site-specific variability. The more ignored question is whether this background variability will confound the index of human disturbance. Using non-forested seasonal wetlands in the northeastern United States, we tested if two common indices of site floristic quality (FQAI, Mean CoC) provide clear signals of site condition relative to gradients of wetland area and surface water depth, and consistent signals across time of year (early vs. late growing season), geomorphic setting (connected vs. isolated), and vegetation community type (pine barrens vernal pond, wet sedge meadow, shrub swamp). Mean CoC is the coefficient of conservatism (a qualitative estimate of species' sensitivity to human disturbance) averaged across the native and exotic taxa observed at a given site, and FQAI is the traditional Floristic Quality Assessment Index where Mean CoC is multiplied by square root of taxa richness. The FQAI did not linearly correspond to the site condition gradient and thus it could not be evaluated. Mean CoC was clearly associated with site condition, with no interference from wetland area or water level (based on computer-intensive resampling of linear model fit). Mean CoC also varied consistently with site condition between the surveys, geomorphic settings, and community types (based on computer-intensive resampling of linear model slope). However, connected wetlands showed inherently greater Mean CoC than isolated wetlands, suggesting a comparison of floristic quality between these categories would not be prudent. Overall this study suggests that FQA in the form of Mean CoC may withstand natural variability in certain non-forested wetland systems. Instead of assuming FQA is overly sensitive to natural variability, we recommend further efforts to identify situations in which FQA is robust.
KW - Conservatism
KW - Ecological condition
KW - Human disturbance
KW - Monitoring
KW - Seasonal wetlands
KW - Vascular plants
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U2 - 10.1016/j.ecolind.2013.05.012
DO - 10.1016/j.ecolind.2013.05.012
M3 - Article
AN - SCOPUS:84879345746
VL - 34
SP - 260
EP - 267
JO - Ecological Indicators
JF - Ecological Indicators
SN - 1470-160X
ER -