1. 南京林业大学生物与环境学院;2. 南京林业大学南方现代林业协同创新中心
1. College of Biology and the Environment, Nanjing Forestry University;2. Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University
Supported by the National Natural Science Foundation of China（Nos.41871097，41471078） and the 333 High-level Talents Fostering Project of Jiangsu Province（Nos. BRA2020339）
滨海湿地生态系统碳汇功能强大，探究其固碳能力对于降低温室气体浓度，缓解全球气候变暖具有重要意义。基于谷歌地球引擎（Google Earth Engine, GEE）提供的1987—2020年Landsat遥感数据及已发表的滨海湿地碳密度数据，使用遥感定量反演与生命地带法相结合的方法，研究中国滨海湿地30多年来碳储量时空变化，结果表明：（1）盐沼湿地主要分布于沿海北部区域，光滩主要分布于沿海东部区域，红树林湿地主要分布于沿海南部区域；（2）中国南部滨海湿地碳密度明显高于北部和东部滨海湿地；（3）中国滨海湿地总碳储量整体呈降低趋势，沿海北部区域与东部区域总碳储量大于南部区域。气候、植被与土地利用变化共同影响了滨海湿地碳储量的时空动态，以围填海为主的人类活动是影响滨海湿地碳储量变化的主要因素。研究结果可为有效评估滨海湿地的碳汇能力，制定减排增汇措施，应对气候变化提供理论依据，也可为我国滨海湿地生态系统管理和退化湿地生态恢复提供决策支持。
【Objective】Rapid increase in the concentrations of greenhouse gases leads to an increase in global warming. The coastal wetland ecosystem has been identified as an important place to fix atmospheric carbon dioxide because of its powerful carbon sink function. Thus, this study aimed to quantitatively assess the temporal and spatial changes of carbon storage in coastal wetlands in China, explore its influencing factors, and augment current global warming management practices. 【Method】Remote sensing data preprocessing, vegetation index calculation and land cover type extraction were carried out based on the data of Landsat atmospheric correction surface reflectance from 1987 to 2020 provided by Google Earth Engine, and then the carbon density data of coastal wetlands in more than 30 literature were collected. Combining remote sensing quantitative inversion with the life zone method, the soil carbon reserves and biomass carbon reserves of coastal wetlands in China were calculated to research the temporal and spatial dynamics of carbon reserves in coastal wetlands in China over 30 years. 【Result】The results showed that: (1) Saltmarsh wetlands were mainly distributed in the northern coastal area, tidal flats in the eastern coastal area, and mangrove wetlands in the southern coastal area; (2) The spatial distribution of carbon density of coastal wetlands in China was quite different. Also, the maximum biomass carbon density, soil carbon density and total carbon density all existed in the region of Shankou mangrove national nature reserve. The values of maximum biomass carbon density, soil carbon density and total carbon density were 220.21 t·hm-2, 130.46 t·hm-2, and 350.46 t·hm-2, respectively. Comparatively, the carbon density of coastal wetlands in southern coastal wetlands was significantly higher than that in northern and eastern coastal wetlands; (3) It was observed that the total carbon storage of coastal wetlands in China showed a decreasing trend as a whole, and its change trend was consistent with the soil carbon reserves. The biomass carbon storage had an increasing trend, with the maximum value of 5.02 Tg, and the soil carbon storage decreased first and then increased, with a maximum value of 35.54 Tg. Also, the total carbon reserves in the northern coastal region and eastern coastal region were greater than that in the southern coastal area. In addition, biomass carbon storage in the northern coastal region showed a decreasing trend, while biomass carbon storage in the eastern and southern coastal areas showed an increasing trend. The soil carbon storage in the northern coastal area, the eastern and southern coastal areas all had a decreasing trend. 【Conclusion】The results estimated in this study are comparable with those published in previous literature. Climate, vegetation and land-use change lead to a decrease in carbon storage in a coastal wetland. Human activities dominated by reclamation are the main factors affecting the dynamics of carbon storage in coastal wetlands. This paper provides a theoretical basis for effectively evaluating the carbon sequestration capacity of coastal wetlands, Also, it outlines suggestions for emission reduction, guidelines for increasing carbon sequestration measures, guides for coping with climate change, and decision support for coastal wetland ecosystem management and ecological restoration of degraded wetlands in China.
LI Jingtai, YAN Dandan, YAO Xiuying, XIE Siying, LIU Yao, SHENG Yufeng, LUAN Zhaoqing. Carbon Storage Estimation of Coastal Wetlands in China[J]. Acta Pedologica Sinica, DOI:10.11766/trxb202106290335,[In Press]