| Abstrakt: |
Effects of herbicides on periphyton communities were evaluated in situ using the Matlock periphytometer to monitor total chlorophyll, chlorophyll a, chlorophyll b, and chlorophyll c after exposure to the herbicides Aatrex®, Roundup®, and Glean® (active ingredients atrazine, glyphosate, and chlorsulfuron). The results indicated that agriculturally (environmentally) realistic concentrations (0–39.0 mg L-1 of active ingredient) of these herbicides did not significantly decrease periphyton biomass. Chlorophyll ratios suggest that these herbicides did change the community composition. Roundup and Glean appear to favor eukaryotic periphyton, and Aatrex appears to favor prokaryotic periphyton. Glean may have an additional hormetic effect on eukaryotic periphyton at low concentrations. [ABSTRACT FROM AUTHOR] |
