Examining the Impacts of Valley Fills on Amphibian and Aquatic Insect Communities in Southeastern Kentucky

Document Type

Dissertation

Publication Title

Biology Department, College of Arts and Sciences, Eastern Kentucky University

Abstract

Chapter 1. Abstract: Biodiversity is not evenly distributed, and understanding factors that determine spatial patterns of species diversity remains a key question in ecology. Because of their relatively high abundance and complex life cycles, stream salamanders and aquatic insects are important trophic links and serve a critical role in transferring energy. Despite this importance little research has examined their community structure simultaneously in aquatic ecosystems. The primary objective of this research was to determine the structure of these communities across natural areas of southeastern Kentucky and understand what factors impact their abundances and distributions. To address this, we sampled eight reference quality streams across the region, March–June 2014. Salamander sampling consisted of three sampling periods on a monthly basis, April–June 2014. Aquatic insect sampling consisted of a single sampling event in March 2014, with water and habitat sampling occurring during each aquatic insect and salamander sampling event. Within each stream, a 100-m reach was sampled for salamanders, aquatic insects, water quality, and habitat measurements. A principle component analysis (PCA) approach was used for factor reduction to create predictive models of environmental variables associated with salamander and aquatic insect abundance and richness. 390 salamanders (155 adult, 235 larvae; 7 species) and 1,163 aquatic insects (8 orders, 33 families) were sampled. Predictive models revealed associations between salamander and aquatic insect abundance and richness, presence and composition of cover objects, and stream pH and conductivity. Understanding patterns of community composition and distribution of aquatic insects and salamanders within reference quality aquatic ecosystems provides important information about ecosystem functioning in undisturbed habitats in this region of high disturbance and anthropogenic land use.

Chapter 2 Abstract: Valley fills due to mountaintop-removal mining bury headwater streams and affect downstream water quality and ecological function. Past studies have focused on generally one taxonomic group or purely habitat and water quality affects. In this study we evaluated stream salamander and aquatic insect communities, metal concentrations in water and tissue, and stream quality and habitat in 10 streams affected by Valley fills (VFS) and 5 reference streams (RS) located in natural areas within 15 km of VFS. Within each stream, a 100-m reach was sampled for the above stated parameters. Salamander sampling consisted of three sampling periods on a monthly basis, April–June 2015. Aquatic insect sampling consisted of a single sampling event in March 2015, with water and habitat sampling occurring during each aquatic insect and salamander sampling event. This study captured 529 individual salamanders of eight species, with captures in RS (n=335) higher than in sampled VFS (n=194). A total of 1,034 aquatic insects representing 8 orders and 37 families were collected, and captures were higher for RS (n=597) than VF (n=447). Abundance, richness, and other community metrics of sampled salamander and aquatic insects were significantly higher in RS than VFS. Several habitat and environmental factors significantly differed between treatments including % silt, conductivity, selenium concentration in water and tissue, and canopy closure likely leading to the reduced communities of salamanders and aquatic insects observed. By approaching the issue of stream health through multiple abiotic factors and taxa, this study provides critical information of the effects of valley fills on stream quality and function.

Publication Date

1-2015

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