BRC-BIO: Interactive effects of ecosystem warming and precipitation regime disturbance on tropical soil greenhouse gas emissions

Forests store large amounts of carbon, not only in the tissues of plants, but also in their soils, in the form of soil carbon. That stored soil carbon can be broken down by soil microbes, such as bacteria and fungi, releasing carbon dioxide and methane to the atmosphere in the process. If changing ecosystem conditions lead to an increase in the rate of carbon dioxide and methane emissions from soils, the storage of forest soil carbon could decrease, with implications for ecosystem carbon balance and soil fertility. This research will examine how two changing ecosystem conditions, temperature and precipitation patterns, may interact to shift the emissions of carbon dioxide and methane from soils in a tropical forest. In addition, this research will enhance the research and quantitative skills of undergraduate students by providing hands-on experiences to both summer research students and students enrolled in a course-based undergraduate research experience class, providing professional development and preparing them for careers in STEM. This research examines how ecosystem warming and altered precipitation regimes affect tropical soil greenhouse gas emissions. This project leverages the Tropical Responses to Altered Climate Experiment (TRACE) in Puerto Rico by adding precipitation manipulations to the existing warming experiment. The objectives are to: (1) quantify soil carbon dioxide and methane flux under varying warming and precipitation scenarios in a field experiment, (2) assess how preceding soil moisture and temperature regimes over time affect carbon dioxide and methane emissions in lab incubations, and (3) predict future soil carbon dioxide and methane fluxes using hierarchical Bayesian models. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.