Date of Award

January 2013

Degree Type

Open Access Thesis

Degree Name

Master of Science (MS)

Department

Biological Sciences

First Advisor

David R. Brown

Department Affiliation

Biological Sciences

Second Advisor

Stephen C. Richter

Department Affiliation

Biological Sciences

Abstract

The Kentucky Wetlands Rapid Assessment Method (KY-WRAM) is currently being developed by the collaborative efforts of the Kentucky Division of Water and Eastern Kentucky University as a tool to measure the function and condition of wetlands. To ensure the rapid assessment method properly evaluates wetland condition, the KY-WRAM needs to be validated by comparison to intensive biological data. This project initiated such a comparison using macroinvertebrate communities. Macroinvertebrates play a critical role in wetland ecosystem functioning, thus it is imperative to have an understanding of the macroinvertebrate community responses to degradation of wetlands. Whereas indices of wetland invertebrate communities have been developed for several states including Minnesota, Ohio, California, and Michigan, such research is lacking in Kentucky wetlands. The objectives of this study were to: (1) Determine which habitat and water quality variables macroinvertebrate communities are sensitive to; (2) Recommend macroinvertebrate metrics to be used in a multimetric index for macroinvertebrate biotic integrity for Kentucky wetlands; (3) Assess the correlation of macroinvertebrate communities of forested depressional wetlands in the Upper Cumberland basin to KY-WRAM scores. Nineteen naturally forested, isolated, ridge-top, ephemeral wetlands were selected in the Daniel Boone National Forest for study. Macroinvertebrates were collected conducting 1-meter sweeps with a D-frame dipnet every 5 meters in the emergent vegetation zone around the perimeter of the wetland. Habitat parameters were measured at the same time as macroinvertebrate sampling and water quality samples were taken one week after the completion of habitat and biotic sampling. All wetlands were scored using the Spring 2011 draft of the KY-WRAM and the Ohio Rapid Assessment Method. Multiple regression analysis comparing macroinvertebrate metrics to habitat variables, water quality, and RAMs were conducted as separate models. Principle Components Analysis was used to evaluate the amount of species variation explained by the RAMs and RAM metrics. A Redundancy Analysis was conducted to model the amount of species variation explained due to habitat and water quality variables. In both multiple regression and multivariate analyses, water quality was not significant and showed few significant relationships to macroinvertebrate community composition. Maximum depth, canopy closure, hummocks and tussocks, and percent vegetative cover were significant in explaining macroinvertebrate community composition in several analyses. These habitat features are also reflected in KY-WRAM metrics that were shown to have significant correlations to the macroinvertebrate community composition, including the KY-WRAM total score and metrics 2, 4, and 6. Some invertebrate metrics are recommended for further research. Because several significant habitat features are also reflective of certain metrics in the KY-WRAM, it is recommended these metrics that reflect important habitat features be considered for adjustment with greater weight so total KY-WRAM score will provide a better reflection of the status of macroinvertebrates. Because this study focused on forested, depressional wetlands, these results should be corroborated by similar macroinvertebrate studies in different wetland types across the varied regions of Kentucky for continued KY-WRAM calibration.

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