{"title":"河口红树林湿地沉积物有机碳动态与积累","authors":"Jian Gong , Weiwei Liu , Wei Li , Lijuan Cui","doi":"10.1016/j.catena.2025.109317","DOIUrl":null,"url":null,"abstract":"<div><div>Estuarine mangrove wetlands are important carbon sinks, yet the mechanisms driving sediment organic carbon (SOC) accumulation and burial remain insufficiently understood. Here, we present comprehensive insights into the distribution, sources, and decomposition of SOC and its fractions, as well as temporal variations in organic carbon accumulation rate (OCAR), across a land-to-sea gradient in mangrove and unvegetated habitats. Our results show that SOC content and storage are significantly higher in mangrove habitats compared to unvegetated ones, both of which decrease with increasing sediment depth, primarily controlled by bulk density (BD) and sediment water content (SWC). Similarly, the distribution patterns of active organic carbon fractions, including easily oxidizable organic carbon, microbial biomass carbon, and dissolved organic carbon, exhibit similar spatial patterns to SOC across habitats. Stable isotope analyses (δ<sup>13</sup>C and δ<sup>15</sup>N) and lignin biomarkers reveal that SOC decomposition is markedly higher in mangrove habitats than in unvegetated areas, potentially driven by plant inputs that enhance microbial processes and accelerate carbon turnover. The contribution of C3 vascular plant-derived terrestrial organic carbon declines significantly along the land-to-sea gradient (from 62.8 % in mangrove habitats to 28.0 % in unvegetated areas), likely due to reduced in situ plant inputs. Structural equation modeling results indicate that sediment accumulation rate (SAR), BD, and SWC are key environmental factors influencing OCAR, while other relevant environmental factors may also contribute. This study enhances our understanding of carbon cycling mechanisms in mangrove wetlands and provides a scientific foundation for their conservation and management.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"259 ","pages":"Article 109317"},"PeriodicalIF":5.7000,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Sediment organic carbon dynamics and accumulation in estuarine mangrove wetlands\",\"authors\":\"Jian Gong , Weiwei Liu , Wei Li , Lijuan Cui\",\"doi\":\"10.1016/j.catena.2025.109317\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Estuarine mangrove wetlands are important carbon sinks, yet the mechanisms driving sediment organic carbon (SOC) accumulation and burial remain insufficiently understood. Here, we present comprehensive insights into the distribution, sources, and decomposition of SOC and its fractions, as well as temporal variations in organic carbon accumulation rate (OCAR), across a land-to-sea gradient in mangrove and unvegetated habitats. Our results show that SOC content and storage are significantly higher in mangrove habitats compared to unvegetated ones, both of which decrease with increasing sediment depth, primarily controlled by bulk density (BD) and sediment water content (SWC). Similarly, the distribution patterns of active organic carbon fractions, including easily oxidizable organic carbon, microbial biomass carbon, and dissolved organic carbon, exhibit similar spatial patterns to SOC across habitats. Stable isotope analyses (δ<sup>13</sup>C and δ<sup>15</sup>N) and lignin biomarkers reveal that SOC decomposition is markedly higher in mangrove habitats than in unvegetated areas, potentially driven by plant inputs that enhance microbial processes and accelerate carbon turnover. The contribution of C3 vascular plant-derived terrestrial organic carbon declines significantly along the land-to-sea gradient (from 62.8 % in mangrove habitats to 28.0 % in unvegetated areas), likely due to reduced in situ plant inputs. Structural equation modeling results indicate that sediment accumulation rate (SAR), BD, and SWC are key environmental factors influencing OCAR, while other relevant environmental factors may also contribute. This study enhances our understanding of carbon cycling mechanisms in mangrove wetlands and provides a scientific foundation for their conservation and management.</div></div>\",\"PeriodicalId\":9801,\"journal\":{\"name\":\"Catena\",\"volume\":\"259 \",\"pages\":\"Article 109317\"},\"PeriodicalIF\":5.7000,\"publicationDate\":\"2025-07-25\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Catena\",\"FirstCategoryId\":\"97\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0341816225006198\",\"RegionNum\":1,\"RegionCategory\":\"农林科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"GEOSCIENCES, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Catena","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0341816225006198","RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
Sediment organic carbon dynamics and accumulation in estuarine mangrove wetlands
Estuarine mangrove wetlands are important carbon sinks, yet the mechanisms driving sediment organic carbon (SOC) accumulation and burial remain insufficiently understood. Here, we present comprehensive insights into the distribution, sources, and decomposition of SOC and its fractions, as well as temporal variations in organic carbon accumulation rate (OCAR), across a land-to-sea gradient in mangrove and unvegetated habitats. Our results show that SOC content and storage are significantly higher in mangrove habitats compared to unvegetated ones, both of which decrease with increasing sediment depth, primarily controlled by bulk density (BD) and sediment water content (SWC). Similarly, the distribution patterns of active organic carbon fractions, including easily oxidizable organic carbon, microbial biomass carbon, and dissolved organic carbon, exhibit similar spatial patterns to SOC across habitats. Stable isotope analyses (δ13C and δ15N) and lignin biomarkers reveal that SOC decomposition is markedly higher in mangrove habitats than in unvegetated areas, potentially driven by plant inputs that enhance microbial processes and accelerate carbon turnover. The contribution of C3 vascular plant-derived terrestrial organic carbon declines significantly along the land-to-sea gradient (from 62.8 % in mangrove habitats to 28.0 % in unvegetated areas), likely due to reduced in situ plant inputs. Structural equation modeling results indicate that sediment accumulation rate (SAR), BD, and SWC are key environmental factors influencing OCAR, while other relevant environmental factors may also contribute. This study enhances our understanding of carbon cycling mechanisms in mangrove wetlands and provides a scientific foundation for their conservation and management.
期刊介绍:
Catena publishes papers describing original field and laboratory investigations and reviews on geoecology and landscape evolution with emphasis on interdisciplinary aspects of soil science, hydrology and geomorphology. It aims to disseminate new knowledge and foster better understanding of the physical environment, of evolutionary sequences that have resulted in past and current landscapes, and of the natural processes that are likely to determine the fate of our terrestrial environment.
Papers within any one of the above topics are welcome provided they are of sufficiently wide interest and relevance.