Rose Martin

Ph.D. Candidate, University of Rhode Island

Conference Travel Grant Type 2 (Joint Aquatic Sciences Meeting)

Effects of Phragmites australis invasion and salinity on greenhouse gas fluxes in two New England salt marshes

ā€œCarbon dioxide (CO2) and methane (CH4) emissions are increasing as a result of anthropogenic activity, driving global climate change. Although salt marshes do not typically produce significant CH4 emissions, exotic species invasion has been shown to lead to increased CH4 fluxes from these systems. Given the rapid rate at which the invasive Eurasian grass Phragmites australis is invading wetlands on the North American East Coast, understanding its potential impacts on CO2 and CH4 emissions will help inform coastal management decisions. In this investigation, differences in CH4 and CO2 fluxes between two salt marsh zones, Spartina patens-dominated high marsh and a Phragmites stand, were measured and compared at two southern New England salt marshes (Fox Hill marsh in Jamestown, RI and Sage Lot Pond in Falmouth, MA) at low tide over the course of one growing season. CO2 consumption was significantly higher and a trend of larger CH4 emissions was detected from the Phragmites zone at Sage Lot Pond. At Fox Hill Marsh, increasing salinity negatively affected CH4 emissions. Further study is required to determine the extent to which abiotic parameters, as opposed to vegetation type, influence CO2 and CH4 fluxes in salt marshes.ā€