Soil carbon consequences of historic hydrologic impairment and recent restoration in coastal wetlands

作者：Meagan J. Eagle, Kevin D. Kroeger, Amanda C. Spivak, Faming Wang, Jianwu Tang, Omar I. Abdul‐Aziz, K. S. Ishtiaq, Jennifer A. O'Keefe Suttles, Adrian G. Mann · 发表于：The Science of The Total Environment · 年份：2022 · DOI：10.1016/j.scitotenv.2022.157682 · 被引用次数：39 · 研究领域：Coastal wetland ecosystem dynamics、Peatlands and Wetlands Ecology、Geology and Paleoclimatology Research

Coastal wetlands provide key ecosystem services, including substantial long-term storage of atmospheric CO2 in soil organic carbon pools. This accumulation of soil organic matter is a vital component of elevation gain in coastal wetlands responding to sea-level rise. Anthropogenic activities that alter coastal wetland function through disruption of tidal exchange and wetland water levels are ubiquitous. This study assesses soil vertical accretion and organic carbon accretion across five coastal wetlands that experienced over a century of impounded hydrology, followed by restoration of tidal exchange 5 to 14 years prior to sampling. Nearby marshes that never experienced tidal impoundment served as controls with natural hydrology to assess the impact of impoundment and restoration. Dated soil cores indicate that elevation gain and carbon storage were suppressed 30–70 % during impoundment, accounting for the majority of elevation deficit between impacted and natural sites. Only one site had substantial subsidence, likely due to oxidation of soil organic matter. Vertical and carbon accretion gains were achieved at all restored sites, with carbon burial increasing from 96 ± 33 to 197 ± 64 g C m−2 y−1. The site with subsidence was able to accrete at double the rate (13 ± 5.6 mm y−1) of the natural complement, due predominantly to organic matter accumulation rather than mineral deposition, indicating these ecosystems are capable of large dynamic responses to restoration when conditi...