EAPS

Atmos/Chem Seminar: Laura Meredith, Arizona University
Date Time Location
February 3rd, 2016 12:00pm-1:00pm 54-1827
"Ecosystem fluxes of hydrogen - new insights into soil microbial H2energy metabolism and linkages to forest phenology" | Atmospheric H2, an indirect greenhouse gas, plays an important role in the chemistry of the atmosphere and stratospheric ozone layer. The budget of atmospheric H2is poorly constrained by the limited available data, especially the largest budget component - uptake of H2 by soil microorganisms. Microbial scavenging of atmospheric H2 has recently been proposed to play a key role in soil microbial survival but confirmation by field measurements is lacking. In this talk, I revisit H2fluxes measured in a mixed temperate forest at the Harvard Forest, MA to investigate the importance of H2 as an energy source to soil microbes, especially in comparison to carbon substrates. The relationship between hydrogen- and carbon-derived energy varied with environmental conditions, such as snow cover, and with forest phenology (e.g., dormant vs growing seasons), which we characterized using automated repeat digital imagery. These camera-based measures of phenology also revealed linkages between emissions of H2from the canopy and forest senescence. The findings at Harvard Forest will help characterize the current role of H2 in the atmosphere and soil biosphere and help reveal the sensitivity of the H2 biogeochemical cycle to environmental change.

EVENT WEBSITE