thumbnail

The role of the upper tidal estuary in wetland blue carbon storage and flux

Global Biogeochemical Cycles

By:
https://doi.org/10.1029/2018GB005897

Links

Abstract

Carbon (C) standing stocks, C mass balance, and soil C burial in tidal freshwater forested wetlands (TFFW) and TFFW transitioning to low‐salinity marshes along the upper estuary are not typically included in “blue carbon” accounting, but may represent a significant C sink. Results from two salinity transects along the tidal Waccamaw and Savannah rivers of the US Atlantic Coast show total C standing stocks were 321‐1264 Mg C ha‐1 among all sites, generally shifting to greater soil storage as salinity increased. Carbon mass balance inputs (litterfall, woody growth, herbaceous growth, root growth, surface accumulation) minus C outputs (surface litter and root decomposition, gaseous C) over a period of up to 11 years were 340‐900 g C m‐2 yr‐1. Soil C burial was variable (7‐337 g C m‐2 yr‐1), and lateral C export was estimated as C mass balance minus soil C burial as 267‐849 g C m‐2yr‐1. This represents a large amount of C export to support aquatic biogeochemical transformations. Despite reduced C persistence within emergent vegetation, decomposition of organic matter, and higher lateral C export, total C storage increased as forests converted to marsh with salinization. These tidal river wetlands exhibited high N mineralization in salinity‐stressed forested sites and considerable P mineralization in low salinity marshes. Large C standing stocks and rates of C sequestration suggest that TFFW and oligohaline marshes are considerably important globally to coastal C dynamics and in facilitating energy transformations in areas of the world in which they occur.

Study Area

Additional publication details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
The role of the upper tidal estuary in wetland blue carbon storage and flux
Series title:
Global Biogeochemical Cycles
DOI:
10.1029/2018GB005897
Volume:
32
Issue:
5
Year Published:
2018
Language:
English
Publisher:
AGU
Contributing office(s):
Wetland and Aquatic Research Center
Description:
23 p.
First page:
817
Last page:
839
Country:
United States
State:
Georgia, South Carolina