SOMMER STARR

In addition to providing critical habitat, marshes offer invaluable ecosystem services like the ability to buffer storm damage to coastal communities and mitigating global change by sequestering CO₂. Salt marshes also filter environmental pollutants and excess nutrients that would otherwise flow into the ocean, thus mitigating marine eutrophication that would impact marine fisheries. Salt marshes do this by providing optimal environmental conditions for anaerobic microorganisms like bacteria and fungi to reduce ammonium and nitrate to atmospheric N₂ gas through the process of denitrification. Marshes have declined globally by 50% in the 20^th century and this loss is projected to worsen with climate change. As a result, $80 million a year is invested towards restoring or building coastal wetland habitat. These manmade marshes quickly return to a natural-looking level of vegetation, but soil chemistry and biogeochemical cycling is slower to stabilize and may never reach natural equivalency. My thesis research explores the role of fungal succession and carbon quality in recovering nitrogen removal ability in engineered coastal wetlands.