DISSERTATION RESEARCH: Identifying Ecological Mechanisms Underlying Soil Microbial Functional Responses to Climate Change

University Of Texas At Austin, Austin TX

Investigators

Abstract

Soil bacteria and fungi are strongly influenced by local precipitation regimes, which are rapidly changing as the planet warms. Because these microorganisms regulate nutrient cycling through ecosystems, it is important to understand how they will respond to wetter or drier conditions. The Edwards Plateau in central Texas is an ideal 'natural laboratory' to study microbial responses to changes in precipitation regime, since mean annual rainfall decreases by 40 cm over a short distance while soil chemistry and plant communities do not change. This project uses both laboratory and field experiments along the Edwards Plateau to understand how changes in microbial populations and communities affect soil processes. Intact soil cores have been transplanted from the dry western end of the Edwards Plateau to the wet eastern end, and vice versa. By monitoring changes in microbial community composition in these cores over time, researchers can link changes in microbial communities with alterations in carbon cycling in response to rainfall. Since many regions of the United States are expected to experience dramatic increases or decreases in precipitation over the next century, farmers, ranchers, and land managers need to understand how plant and soil communities will respond to changing climates. This study will shed light on the mechanisms by which microbial communities acclimate to altered rainfall patterns; results will help local landowners prepare for changes in precipitation. The investigators will engage undergraduate students, and particularly those from under-represented groups, in their field research. Through the University of Texas Freshman Research Initiative program, undergraduates will have the opportunity to learn standard field ecology techniques and novel, next-generation sequencing methods for identifying bacterial and fungal species in environmental samples.