Climate Change
Currently, most research in the Casper lab takes place in semi-arid steppe grassland in Northern Mongolia, a fascinating ecological system that has supported nomadic pastoralism for thousands of years and is experiencing some of the greatest temperature increases worldwide. Studies are aimed at understanding the basic ecology of the system and how that ecology will be impacted by climate change. The main experiment involves the use of open top and open-sided warming chambers to elevate temperature, crossed with watering and grazing treatments. Of particular interest is how warming affects the structure of the plant and soil microbial communities. The experiment takes into account landscape scale variation in grazing patterns, soil moisture, nitrogen inputs via nitrogen fixation (as suggested by nitrogen isotopes in plant tissue), and nutrient availability. One project asks whether functional leaf traits predict species-specific responses to warming. Another examines whether the strength of plant-plant competition varies across the landscape and with the experimental treatments. Still another examines the pollination biology of dicotyledons within the steppe and whether and how grazing affects floral traits and pollination success.
For more information, please visit our website:
http://mongolia.bio.upenn.edu/