The objective of the proposed research is to understand how temperature and colored dissolved organic matter (CDOM) influence the impact of UV on food webs in lakes. We hypothesize that climate change will regulate UV damage at both the molecular level (by altering temperature), and at the ecosystem level (by altering CDOM). We hypothesize that high UV, low temperature conditions will favor plant-based food webs while lower UV: temperature ratios conditions will favor bacteria-based food webs, with important consequences for zooplankton, fish, and ecosystem structure and function. A carefully focused set of analytical and experimental approaches will test these hypotheses in the lab, and in the field at different elevations with different UV and CDOM conditions.
It is widely recognized that environmental UV is damaging, but little is known about how molecular repair of UV damage varies with temperature or how these effects propagate up to the ecosystem level. The proposed research will advance our understanding of how lakes are likely to respond to future changes in temperature and UV related to alteration of climate and ozone. Students will be closely integrated into the research to provide them with the diverse range of quantitative skills necessary to tackle some of the complex issues that environmental biologists face in this period of human-accelerated environmental change.
