Bryan Mark, the Ohio State University
With recognition that high-elevation environments are highly responsive to changes in temperature and precipitation, it is critical that we improve our understanding of how global climate change will affect freshwater resources and aquatic ecosystems in subalpine and alpine environments (Bradley et al. 2004; Parker et al. 2008). Further, the concern over changing water availability in the Intermountain West adds merit to alpine research. Improving our knowledge of the characteristics and behavior of aquatic ecosystems in alpine environments will strengthen our ability to develop meaningful adaptation strategies and scenarios describing the potential future response of these freshwater systems to projected climate change. Insight will also improve our ability to effectively manage these natural systems and the freshwater resources they contain (Adrian et al. 2009).
Lakes in Great Basin National Park are ideal for studying both past and future changes because of their protected status and relative lack of direct human influence. Paleolimnology is an excellent tool to study past changes by extracting information preserved in lake sediment records. In this way we can study the past distribution of aquatic fauna in high-elevation lakes and establish baseline conditions against which the effects of projected warming in these regions can be evaluated. In addition, paleolimnology can be used to assess how the biotic and abiotic components of aquatic ecosystems have responded to anthropogenic and natural stressors (Fenn et al. 2003; Parker et al. 2008).
Using remains of lake midges that are preserved in the lake sediments as a proxy for temperature, we have been able to describe variability in the park climate over almost 7,000 years.
We have initiated a collaborative research project to assess climate change in Great Basin National Park, Nevada, using paleolimnology and direct climate observations. Using remains of lake midges (insects in the order Diptera, family Chironomidae) that are preserved in the lake sediments as a proxy for temperature, we have been able to describe variability in the park climate over almost 7,000 years. We also have deployed a network of climate microloggers to complement the limnological work and better characterize current lake-specific climate conditions for comparison with today’s midge communities and the longer lake core records.