Loading...
Coastal Forest Seawater Exposure Increases Stem Methane Concentration
Norwood, Matthew J. Ward, Nicholas Kirwan, Matthew L. Hopple, Anya Megonigal, J. Patrick
Norwood, Matthew J.
Ward, Nicholas
Kirwan, Matthew L.
Hopple, Anya
Megonigal, J. Patrick
Abstract
Methane (CH4) exchange between trees and the atmosphere has recently emerged as an important, but poorly quantified process regulating global climate. The sources (soil and/or tree) and mechanisms driving the increase of CH4 in trees and degassing to the atmosphere are inadequately understood, particularly for coastal forests facing increased exposure to seawater. We investigated the eco‐physiological relationship between tree stem wood density, soil and stem oxygen saturation (an indicator of redox state), soil and stem CH4 concentrations, soil and stem carbon dioxide (CO2) concentrations, and soil salinity in five forests along the United States coastline. We aim to evaluate the mechanisms underlying greenhouse gas increase in trees and the influence of seawater exposure on stem CH4 accumulation. Seawater exposure corresponded with decreased tree survival and increased tree stem methane. Tree stem wood density was significantly correlated with increased stem CH4 in seawater exposed gymnosperms, indicating that dying gymnosperm trees may accumulate higher levels of CH4 in association with seawater flooding. Further, we found that significant differences in seawater exposed and unexposed gymnosperm tree populations are associated with increased soil and stem CH4 and CO2, indicating that seawater exposure significantly impacts soil and stem greenhouse gas abundance. Our results provide new insight into the potential mechanisms driving tree CH4 accumulation within gymnosperm coastal forests.
Description
Date
2021-02-01
Journal Title
Journal ISSN
Volume Title
Publisher
Collections
Download Dataset
Rights Holder
Usage License
Embargo
Research Projects
Organizational Units
Journal Issue
Keywords
Physical Sciences Peer-Reviewed Articles, coastal forest, greenhouse gas exchange, methane, seawater exposure
Citation
Advisor
Department
Virginia Institute of Marine Science
DOI
https://doi.org/10.1029/2020JG005915