SOMMER STARR

Fungi are ubiquitous across ecosystems and play diverse roles therein. Best known for their role in decomposition, fungi are the primary mineralizers of lignin, a recalcitrant carbon compound found in woody plant tissues. Through decomposition, fungi help to release sequestered carbon and nutrients back into the system and are thus important players in the global carbon and nitrogen cycles. In salt marshes, highly diverse communities of fungi are largely responsible for carbon and nitrogen mobilization between the primary production and detrital food webs. Importantly, fungi can remove excess nitrogen directly via denitrification; but little is known about whether fungal denitrification is an important nitrogen removal pathway in coastal wetlands. My thesis research evaluates the contribution of fungi to total denitrification in salt marshes and compares the denitrifier communities of natural and constructed salt marshes in Mobile county, Alabama. By using selective inhibitory compounds and acetylene block technique, we can measure the contributions of both fungi and bacteria to nitrous oxide production using gas chromatography. We are also looking at how each group of microorganisms responds to different types of carbon additions and working with collaborators to characterize the fungal communities of these systems using eDNA analysis.