| In order to develop tools to assess the biotic integrity of isolated herbaceous depressional wetlands of peninsular Florida, 75 small (∼1 ha) wetlands along a gradient of human disturbance were studied, and algae (diatoms), macrophytes, and macroinvertebrates collected and analyzed. Physio-chemical constituents of the water and soil were also collected and analyzed. Three indices of wetland integrity were developed based on measurable attributes (metrics) of the assemblages sampled: the Diatom Index of Wetland Condition (DIWC, 14 metrics), Vegetative Index of Wetland Condition (VIWC, 5 metrics), and the Macroinvertebrate Index of Wetland Condition (NIIWC, 5 metrics). Each index was significantly correlated (Spearman's r ≥ 10.751, p < 0.0001) with an independent geographic information systems-based measure of human landscape modification, the Landscape Development Intensity index.; A secondary goal of this research was to elucidate the various landscape and soil/water physio-chemical constituents responsible for determining the community composition of the sampled wetlands, as understanding the driving forces may aid in managing wetland resources. The dimensionality of each dataset was reduced using non-metric multidimensional scaling (NMDS), and correlations of site scores in ordination space made with measured physio-chemical constituents, LDI score, and latitude/longitude. Four variables acting on various spatial scales were correlated (Pearson's r2 > 0.30) with all three assemblages: soil pH, water column specific conductivity, water column total phosphorous (TP), and LDI score. In addition, water color (macroinvertebrates) and latitude (macrophytes) were also correlated with the ordination site scores.; The indices of biotic integrity developed from this research may be used to provide quantitative and objective measurement of the aquatic resources of peninsular Florida and may form the scientific basis for an objective and quantifiable rapid assessment procedure. In addition, results from this study suggested that efforts to restore community composition and associated processes and functions should focus on amending inflows and fluxes of water, materials, and energy that affect soil pH, specific conductivity, and water TP, as well as decreasing the abundance of human-developed lands within 100m of wetlands. |
