Differential effects of chronic and acute simulated seawater intrusion on tidal freshwater marsh carbon cycling.

ABSTRACT: Tidal freshwater ecosystems experience acute seawater intrusion associated with periodic droughts, but are expected to become chronically salinized as sea level rises. Here we report the results from an experimental manipulation in a tidal freshwater Zizaniopsis miliacea marsh on the Altamaha River, GA where diluted seawater was added to replicate marsh plots on either a press (constant) or pulse (2 months per year) basis. We measured changes in porewater chemistry (SO₄ ^2-, Cl^-, organic C, inorganic nitrogen and phosphorus), ecosystem CO₂ and CH₄ exchange, and microbial extracellular enzyme activity. We found that press (chronic) seawater additions increased porewater chloride and sulfate almost immediately, and ammonium and pho

SUBMITTER: Herbert ER 

PROVIDER: S-EPMC6750722 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature