loading page

Understanding soil moisture and salinity effects on greenhouse gas fluxes from coastal soils
  • Ben Bond-Lamberty,
  • Stephanie Pennington,
  • Nicholas Ward
Ben Bond-Lamberty
Pacific Northwest National Laboratory

Corresponding Author:bondlamberty@pnnl.gov

Author Profile
Stephanie Pennington
Pacific Northwest National Laboratory
Author Profile
Nicholas Ward
Pacific Northwest National Laboratory
Author Profile

Abstract

How will coastal forests respond to rising sea levels, disturbances such as storms, drought, and climate change, which are combining to cause widespread impacts on ecosystems at the terrestrial-aquatic interface? One particular area of uncertainty is how these processes may mobilize soil organic carbon, resulting in changes in the dissolved or gaseous greenhouse gas (GHG) fluxes. We present results from the first year of a manipulative experiment looking at the effects of changes in salinity exposure and water availability on soil GHG fluxes. Large (40 cm diameter) soil cores were transplanted along natural salinity and elevation gradients in a Maryland, USA, coastal forest subject to rapid sea level rise. Comparative observations were also made in a western Washington, USA watershed with slow sea level rise but strong tidal fluctuations. Disturbed and undisturbed control cores allow us to distinguish transplant from salinity effects; soil respiration measurements were made every 7-10 days. Cores transplanted to lower-salinity sites, and to higher-elevation plots, exhibited elevated GHG fluxes relative to disturbance controls. These preliminary results suggest that changes in salinity exposure and water availability may exert significant effects on coastal forest GHG fluxes and the stability of soil carbon.