The effects of salinity intrusion on the biogeochemistry of Hudson River tidal freshwater wetlands

摘要: Rising sea levels and stronger storm surges may cause a northward migration of the saltwater front in lower Hudson River estuary, exposing tidally influenced freshwater wetlands to saline waters. Previous research has documented changes tidal wetland biogeochemistry response salinity intrusion due increased sulfate reduction resulting sulfide concentrations. Sulfide not only favors shift from denitrification dissimilatory nitrate ammonia (DNRA), but can also increase organic matter mineralization, net loss material subsequent decreases elevation. Without continued accretion matter, will keep pace with rising levels. To better understand effects on biogeochemical cycling, descriptive measurements sediment along gradient were conducted using microelectrodes during two field sampling events (June August 2011). Additionally, series laboratory experiments sediments varying salinities measurement oxygen hydrogen profiles. Mean maximum concentrations varied 12 mg O2/L June <8 August. was present all site significantly higher retention more sites (p<0.01). Higher measured cores experimentally subjected (17 psu). These data suggest that exposure water threaten quality sustainability brackish region estuary through biogeochemistry.