The Kueppers lab is pursuing four main research areas using both field measurements and computational approaches.
Ecological Consequences of Climate Change
Past and future climate change can have diverse effects on ecological systems, including shifts in the geographic ranges of species. We began the Alpine Treeline Warming Experiment to learn how subalpine and alpine species' geographic distributions may be altered by climate warming in the Colorado Rocky Mountains. We also have established GLORIA sites to observe alpine ecosystem change through time near the Rocky Mountain Biological Lab. Finally, we have modeled potential range shifts by endemic species, such as California's blue oak, with projected regional climate change, using statistical models and GIS software, as well as output from regional climate models.
Alpine Treeline Warming Experiment
Alpine ecosystems can thought of as islands of biodiversity, isolated from each other by surrounding lower elevation forested areas. The species in these ecosystems may be particularly vulnerable to a warming climate given their isolation and adaptations to very cold conditions and short growing seasons. In addition, an advance in high-elevation treeline may alter local hydrology, biodiversity, and nutrient cycling. The ATWE uses infrared heaters to warm soil and plant surfaces by an amount comparable to current average projections of climate warming in the year 2100. We are examining the effects this warming may have on alpine and subalpine plant species and communities. The experiment is being conducted on Niwot Ridge, above Boulder, Colorado.
Two-way interactions between climate and ecosystems that amplify or damp the climate's initial response to elevated greenhouse gas concentrations are known as feedbacks. Amplifying interactions are considered positive feedbacks, and dampening interactions are considered negative feedbacks. We are currently using a regional climate model to quantify the climate's sensitivity to regional scale changes in ecosystem properties and distribution. In past work at the Rocky Mountain Biological Laboratory, we conducted field measurements to help us understand how montane and subalpine forest carbon cycling responds to natural climate variation.
Regional Land Use Change
Land cover and land use change (i.e., converting natural vegetation to a new type, or to agricultural or urban land) has profoundly affected the landscape. In California alone, over 18 million acres are used for irrigated agriculture. Changing land cover and land use may significantly affect local and regional climate. We are exploring these effects using regional climate models and the state of California as our initial case study. We hope to establish some new field sites in California’s Central Valley to help us improve the way our models represent agricultural and suburban land.