Project Title: Impacts of temperature and nitrogen addition on greenhouse gas fluxes from turfgrass and coastal salt marshes
Mentor: Serena Moseman-Valtierra, Ph.D.
Abstract: Climate change and nitrogen (N) loading from wastewater and fertilization are both increasingly significant anthropogenic drivers of ecosystem change. Among the ecosystems affected by these drivers are coastal salt marshes, although turf grasses are often direct recipients of N inputs prior to their discharge to the coast. To estimate changes in greenhouse gas emissions from coastal marsh grasses and turfgrasses, we created a mesocosm experiment using a common turfgrass (Schedonorus arundinaceus) and a dominant native coastal cordgrass (Spartina alterniflora) in growth chambers kept under current and projected future temperatures with or without added N inputs. For N fertilization, we used recovered biosolids from wastewater sludge. We measured fluxes of N2O, CO2, and CH4 in the mesocosms through a growing season, the summer of 2016. Above and belowground biomass will be compared between experimental treatments and tested as a potential proxy for CO2 fluxes along with soil properties, including salinity, moisture, and DIN. Preliminary results indicate that there were few significant fluxes of N2O from the mesocosm plots. Both the highest N2O and CO2 emissions (9.6 umol m-2 h-1 and 15.1 m-2 s-1 respectively) were measured from turfgrass mesocosms. The highest CH4 emissions (61.9 umol m-2 h-1) were measured from cordgrass mesocosms. This data will be used to determine if fertilization using recovered biosolids is a sustainable method of fertilizer application.