文献类型：期刊文献

英文题名：Contrasting SOC accumulation pathways in estuarine wetlands: evidence from isotopes, biomarkers, and 210Pb chronologies

作者：Gong, Jian[1,2,3,4] Liu, Weiwei[1,2,3,4] Cui, Lijuan[1,2,3,4] Li, Wei[1,2,3,4] Liu, Haoran[1,2,3,4]

第一作者：Gong, Jian

通信作者：Cui, LJ[1]

机构：[1]Chinese Acad Forestry, State Key Lab Wetland Conservat & Restorat, Beijing 100091, Peoples R China;[2]Chinese Acad Forestry, Inst Ecol Conservat & Restorat, Beijing 100091, Peoples R China;[3]Chinese Acad Forestry, Inst Wetland Res, Beijing 100091, Peoples R China;[4]Beijing Key Lab Wetland Ecol Funct & Restorat, Beijing 100091, Peoples R China

年份：2026

卷号：666

外文期刊名：JOURNAL OF HYDROLOGY

收录：;EI(收录号：20260219871167);Scopus(收录号：2-s2.0-105026665730);WOS:【SCI-EXPANDED(收录号:WOS:001653969400003)】；

基金：This work is supported from the National Key R & D Program of China (grant: 2022YFF1301000) , the National Natural Science Foun-dation of China (grant: 72474215 and 72104236) , the Fundamental Research Funds of Chinese Academy of Forestry (grant: CAFYBB2023MB018) .

语种：英文

外文关键词：SOC; Estuarine wetlands; Source attribution; Carbon sequestration; Pb-210 dating

摘要：The accumulation characteristics and evolutionary mechanisms of sedimentary organic carbon (SOC) density across diverse estuarine depositional environments remain insufficiently understood. Accordingly, we investigated the distribution patterns, source contributions, and long-term dynamics of SOC density using multi-proxy analyses of sediment cores from estuarine wetlands. Results revealed pronounced variations in SOC density between depositional settings. SOC density ranged from 0.06 to 1.85 kg/m(2), with significantly higher values in vegetated sediments (0.12-1.85 kg/m(2)) than in unvegetated ones (0.06-0.42 kg/m(2)). Vegetated environments exhibited surface-layer enrichment, primarily driven by sustained plant-derived carbon inputs. In contrast, unvegetated environments showed deep-layer accumulation, attributed to enhanced physical protection associated with fine-grained sedimentation. Random forest analysis identified organic carbon accumulation rate (OCAR) and particle size composition as the dominant controls on SOC accumulation. Source apportionment based on stable isotopes and lignin biomarkers revealed that vegetation-derived carbon (fv) dominated in vegetated habitats and significantly enhanced SOC density, whereas marine inputs (fm) remained spatially invariant. Chronologies based on Pb-210 dating revealed contrasting temporal trends in SOC density across habitats. In vegetated habitats, the SOC trajectory can be divided into three temporal phases-baseline (similar to 1944-1978), anthropogenic disturbance (1978-1990), and ecological restoration (post-1990). Across these phases, SOC increased from similar to 0.32 kg/m(2) in the 1940 s to similar to 1.85 kg/m(2) in the 2010 s, with the post-1990 rise driven by vegetation recovery and hydrological rehabilitation. In contrast, SOC in unvegetated habitats declined from similar to 0.42 kg/m(2) in the 1990 s to similar to 0.11 kg/m(2) after 2016, constrained by reduced fine-sediment input and limited organic supply. Partial Least Squares Structural Equation Modeling (PLS-SEM) identified divergent accumulation pathways: in vegetated systems, hydrology indirectly enhanced SOC through sediment fining and macrophyte inputs, whereas in unvegetated systems, SOC was predominantly controlled by OCAR and grain-size coarsening, with OCAR explaining up to 57 % of the variance.