河口型红树林湿地土壤有机碳储量与来源特征  

Characterizing Storage and Sources of Soil Organic Carbon in Estuarine Mangrove Wetlands

作　　者：王飞飞 吴高杰 杨盛昌 曹文志 WANG Feifei;WU Gaojie;YANG Shengchang;CAO Wenzhi(Key Laboratory of Ministry of Education for Coastal and Wetland Ecosystems,College of Environment and Ecology,Xiamen University,Xiamen 361102,Fujian,P.R.China)

机构地区：[1]厦门大学滨海湿地生态系统教育部重点实验室,厦门大学环境与生态学院,福建厦门361102

出　　处：《湿地科学》2024年第5期664-673,共10页Wetland Science

基　　金：国家自然科学基金重点项目(42230407);国家重点研发计划项目(2022YFF1301301)资助。

摘　　要：红树林在沿海生态系统碳循环和碳收支过程中发挥着重要作用,识别红树林土壤有机碳来源和变化特征具有重要意义。2016年3月(春季)和11月(秋季),以福建省龙海九龙江口红树林省级自然保护区河口型红树林湿地为研究对象,采集秋茄(Kandelia obovata)中龄林和成熟林中靠陆端和靠海端林内土壤及光滩土壤,研究0~100 cm深度土壤有机碳含量和储量的变化特征,并利用稳定同位素混合模型(SIMMR)识别土壤有机碳不同潜在来源的贡献。结果表明,中龄林和成熟林土壤有机碳质量分数分别为9.80~30.10 g/kg和9.40~30.97 g/kg,秋季土壤有机碳储量分别比春季高了25.6%和19.1%;土壤δ^(13)C值和δ^(15)N值范围分别为-28.20‰~-23.68‰和2.39‰~10.98‰,其中δ^(13)C值在靠海端和光滩中均高于靠陆端;海水养殖产生的颗粒有机物是土壤有机碳的主要来源,其平均贡献率为(32.6±3.7)%,其次是上游河流带来的颗粒有机物和C3植物,平均贡献率分别为(23.3±10.2)%和(20.1±0.9)%;海水养殖和C3植物的贡献率均在靠陆端红树林最高,而河流的贡献率在光滩土壤中最高,本地源对土壤有机碳的贡献率存在季节差异;红树林湿地土壤有机碳储量沿由内陆向海岸方向逐渐降低,土壤有机碳主要来源于外来源,本地源在红树林林内土壤中起到了重要作用。可见,红树林生态系统具有较强的碳捕获和碳固存能力。Mangroves play a crucial role in carbon cycle and budget of coastal ecosystems,and it is important to identify the source and variation characteristics of mangrove soil organic carbon.In March(spring)and No-vember(autumn)of 2016,mangrove wetland in the Jiulong River Estuary Mangrove Provincial Nature Re-serve in Longhai,Fujian Province was selected as study object,soils of landward mangrove,seaward man-grove,and tidal flat in half-mature and mature forests of Kandelia obovate were collected to analyze the changes of soil organic carbon contents and storages at 0-100 cm depths,and the contributions of different po-tential sources of soil organic carbon were identified using the Stable Isotope Mixing Model(SIMMR).The re-sults showed that the soil organic carbon contents in half-mature and mature forests were ranged from 9.80 to 30.10 g/kg and 9.40 to 30.97 g/kg,respectively,and their storages in autumn were 25.6%and 19.1%higher than those in spring,respectively.The δ^(13)C and δ^(15)N values in all soils ranged from-28.20%o to-23.68%o and 2.39%o to 10.98%o,respectively.The δ^(13)C values in seaward mangrove and tidal flat soils were higher than in landward mangrove.Maricultural particulate organic matter was the main source of soil organic carbon,with an average relative contribution of(32.6±3.7)%,followed by riverine particulate organic matter(23.3±10.2%)and C3 plants(20.1±0.9%).The contribution proportion of mariculture and C3 plants was highest in the land-ward mangrove,while the contribution of river was highest in the tidal flat soil.Moreover,the contribution of autochthonous sources to soil organic carbon showed seasonal differences.Soil organic carbon storage in man-grove wetland decreased from landward to seaward,and soil organic carbon mainly originates from allochtho-nous sources.Therefore,mangrove ecosystems have strong capacity for carbon capture and sequestration.

关 键 词：红树林 土壤有机碳 稳定同位素 溯源 

分 类 号：S153[农业科学—土壤学]