Annual carbon sequestration and loss rates under altered hydrology and fire regimes in southeastern USA pocosin peatlands.

Journal Article (Journal Article)

Peatlands drained for agriculture or forestry are susceptible to the rapid release of greenhouse gases (GHGs) through enhanced microbial decomposition and increased frequency of deep peat fires. We present evidence that rewetting drained subtropical wooded peatlands (STWPs) along the southeastern USA coast, primarily pocosin bogs, could prevent significant carbon (C) losses. To quantify GHG emissions and storage from drained and rewetted pocosin we used eddy covariance techniques, the first such estimates that have been applied to this major bog type, on a private drained (PD) site supplemented by static chamber measurements at PD and Pocosin Lakes National Wildlife Refuge. Net ecosystem exchange measurements showed that the loss was 21.2 Mg CO2  ha-1  year-1 (1 Mg = 106  g) in the drained pocosin. Under a rewetted scenario, where the annual mean water table depth (WTD) decreased from 60 to 30 cm, the C loss was projected to fall to 2 Mg CO2  ha-1  year-1 , a 94% reduction. If the WTD was 20 cm, the peatlands became a net carbon sink (-3.3 Mg CO2  ha-1  year-1 ). Hence, net C reductions could reach 24.5 Mg CO2  ha-1  year-1 , and when scaled up to the 4000 ha PD site nearly 100,000 Mg CO2  year-1 of creditable C could be amassed. We conservatively estimate among the 0.75 million ha of southeastern STWPs, between 450 and 770 km2 could be rewet, reducing annual GHG emissions by 0.96-1.6 Tg (1 Tg = 1012  g) of CO2 , through suppressed microbial decomposition and 1.7-2.8 Tg via fire prevention, respectively. Despite covering <0.01% of US land area, rewetting drained pocosin can potentially provide 2.4% of the annual CO2 nationwide reduction target of 0.18 Pg (1 Pg = 1015  g). Suggesting pocosin restoration can contribute disproportionately to the US goal of achieving net-zero emission by 2050.

Full Text

Duke Authors

Cited Authors

  • Richardson, CJ; Flanagan, NE; Wang, H; Ho, M

Published Date

  • November 2022

Published In

Volume / Issue

  • 28 / 21

Start / End Page

  • 6370 - 6384

PubMed ID

  • 36054687

Electronic International Standard Serial Number (EISSN)

  • 1365-2486

International Standard Serial Number (ISSN)

  • 1354-1013

Digital Object Identifier (DOI)

  • 10.1111/gcb.16366


  • eng