Climate change in Great Basin National Park: Lake sediment and sensor-based studies

Alpine and subalpine aquatic ecosystems are highly susceptible to direct and indirect effects of climate change, making them ideal study sites. We recovered a sediment core spanning the last 7,000 years from Stella Lake and a core of the last 100 years from Baker Lake in Great Basin National Park, Nevada, in 2005 and 2007. We examined the cores for subfossil chironomid (Insecta: Diptera: Chironomidae; i.e., midge) remains. The midge communities in the lakes underwent little compositional change through much of the 20th century; however, after 1980 a rapid lake-specific faunal turnover was observed. Because of limited dispersal ability and restricted habitats, some lake species will be extirpated by climate change. Fortunately, lake cores show that even during the most arid periods the lakes did not completely desiccate, but continued to support lake biological communities. To complement the limnological work, an air temperature and humidity micrologger network was deployed in 2005 and expanded in subsequent years, now numbering 36 instruments. The sensor network that spans the full park elevation range (1,639-3,892 m/5,377-13,063 ft) indicates coherent seasonal and elevational variations, which help to interpret the paleolimnology data. Climate models indicate increasing temperatures and uncertain change in precipitation for the Great Basin region. Although we may not be able to protect all ecosystems faced with climate change, our collaborative educational research project exemplifies how the National Park Service is equipped to document and interpret climate change.