How important are gas diffusion vs. microbial community properties for structuring rates of methane consumption in upland soils?
Two factors drive variability in methane consumption rates in upland soils: the transport of methane from the atmosphere into the soil and the consumption of methane by the community of methanotrophs. This microbial activity is, in turn, determined by methanotroph population size and enzymatic properties (i.e., Michaelis-Menten kinetics). My work on the Shortgrass Steppe Long Term Ecological Research site (SGS LTER) seeks to characterize the relative importance of these controls for structuring variance in the exchange of methane between soils and the atmosphere within and among sites. With funding from the SGS LTER, I regularly assay methanotroph activity using additions of an inert tracer that are coincident with methane flux measures. By measuring dynamics of both methane and the inert tracer, I simultaneously and uniquely measure the physical transport and biological transformations that collectively regulate methane flux. My results are revealing that the response of methane flux
