Measuring Variation in Ecosystem Sensitivity to Stress
Abstract
The objectives of this study were to develop a method for measuring biological responses to stress in situ and to use this method to evaluate the extent to which stream ecosystems vary their sensitivity to anthropogenic stress. Chemical-diffusing substrates were constructed from tissue culture flasks and ceramic tiles, which provided a surface that was suitable for the growth of stream microorganisms and porous to most chemicals. Static laboratory tests showed that many common classes of chemicals diffused through these substrates in a highly predictable manner. A laboratory stream study provided further evidence for repeatable diffusion rates and allowed for the standardization-of a sampling protocol for characterizing microbial community responses to stress. Two field studies were conducted using the diffusers to evaluate interecosystem variation in stream microbial responses to experimental gradients of sulfuric acid and chlorine. Data analyses from these experiments are ongoing, but indicate that predictable responses to such gradients can be obtained in situ and analyzed using conventional statistical techniques. The protocol developed during the first year of this study has broad applications for both basic and applied research in environmental science.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 28, 1992
- Accession Number
- ADA259521
Entities
People
- Eric P. Smith
- John Cairns Jr.
- Paul V. Mccormick
Organizations
- Virginia Tech