Date of Award

8-10-2000

Degree Type

Thesis

Degree Name

Master of Science

Department

Integrated Environmental Sciences

First Advisor

Mary E. Lehman, Ph.D.

Second Advisor

Dana P. Johnson, M.S.

Third Advisor

Kathleen Register

Abstract

Heavy metals in the environment pose a risk to human health as well as to ecosystem health. These metals are released into the atmosphere as a result of industrial processes, and can be transported away from their sources to be deposited into the environment. Ectohydric mosses are known accumulators of atmospheric heavy metals, and their tissue can be used to quantify integrated deposition of these metals over time in the ecosystem.

In this study, the moss Thuidium delicatulum (Hedw.) was used to quantify lead (Pb), copper (Cu), chromium (Cr), and nickel (Ni) concentrations in the central Blue Ridge of Virginia . Projects using moss as a bioindicator of heavy metals on a landscape scale have been infrequent in the southern U.S. and have never occurred in the Blue Ridge. The objectives of the project were to evaluate the suitability of this moss for a moss-monitoring study, to assess the effects of several geographical and environmental variables on deposition, and to contribute to the current literature regarding the deposition of heavy metals in the Appalachians.

The moss was sampled on four mountains in the Blue Ridge in the Spring of 2000 following the protocol of the standard European moss-monitoring method (Markert et al. 1996). Metal concentrations in the samples of T. delicatulum corresponded with levels found in other North American and European studies.

Overall concentrations of three metals were significantly higher on one mountain, and some trends based on elevation were observed among metal concentrations in the moss sampled at all sites. A significant difference in mean metal levels, however, was observed in moss sampled under pine canopies as opposed to moss sampled under deciduous canopies. Data was standardized to account for this disparity. After reanalysis, some previous trends were altered or no longer significant, however, some new correlations emerged within the entire data set.

A lack of substrate association for metals tested and significant metal/metal correlations between Pb, Cu, and Ni suggest that the concentrations observed during this study are accurate representations of local levels of these three metals. Therefore, the applications of this method throughout the physiographic province of the Blue Ridge and the southern Appalachians in future biomonitoring are discussed.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.