不同水位梯度和植被类型对洞庭湖湿地土壤有机碳储量的影响  

Influences of DifferentWater Level Gradients and Vegetation Types on Soil Organic Carbon Storage in the Dongting LakeWetland

作　　者：彭方成 汤安民 边华林 李有志[1] PENG Fangcheng;TANG Anmin;BIAN Hualin;LI Youzhi(Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area,College of Environment and Ecology,Hunan Agricultural University,Changsha 410128,Hunan,P.R.China;Management Office of Xinqiang River National Wetland Park,Yueyang County,Yueyang 414100,Hunan,P.R.China;Guangdong International Engineering Consulting Co.Ltd.,Guangzhou 510030,Guangdong,P.R.China)

机构地区：[1]湖南农业大学环境与生态学院洞庭湖区农村生态系统健康湖南省重点实验室,湖南长沙410128 [2]湖南省岳阳县新墙河国家湿地公园管理处,湖南岳阳414100 [3]广东省国际工程咨询有限公司,广东广州510030

出　　处：《湿地科学》2023年第6期868-875,共8页Wetland Science

基　　金：国家自然科学基金区域创新发展联合基金重点项目(U21A2009);湖南省重点研发计划项目(2022SK2088);湖南省自然科学基金项目(2021JJ30330)资助。

摘　　要：湿地土壤有机碳受到水文和植被的双重调控。以洞庭湖湿地川三蕊柳(Salix triandroides)和短尖薹草(Carex brevicuspis)群落为研究对象,研究3种水位梯度(−60 cm、−40 cm和−20 cm,分别表示水位在土壤表层以下60 cm、40 cm和20 cm)下湿地土壤有机碳储量及碳输入特征,从而为湿地碳汇评估提供科学依据。结果表明,川三蕊柳群落土壤有机碳储量以高水位区域较高,而短尖薹草群落土壤有机碳储量以中水位区域较高;在低水位和高水位区域,川三蕊柳群落土壤有机碳储量高于短尖薹草群落,而在中水位区域,川三蕊柳群落土壤有机碳储量低于短尖薹草群落;两种植物群落泥沙淤积有机碳密度随着水位的增加而增加,并在两种植物群落之间无显著差异;凋落物有机碳密度随水位的增加先增加后降低,且在川三蕊柳群落显著高于短尖薹草群落;在土壤有机碳来源上,两种植物群落均以泥沙淤积有机碳为主、植物凋落物有机碳为辅,泥沙淤积有机碳对短尖薹草群落土壤有机碳的贡献高于川三蕊柳群落。可见,在湿地恢复过程中,可以根据水位特点,选取适宜的植被类型,以增强湿地碳汇功能。Soil organic carbon in wetland is regulated by both hydrology and vegetation.Taking communities of Salix triandroides and Carex brevicuspis in the Dongting Lake wetland as research objects,the characteristics of soil organic carbon storage and carbon input under three water level gradients(−60 cm,−40 cm and−20 cm,indicating the water level is 60 cm,40 cm,and 20 cm below the soil surface,respectively)were studied to provide scientific basis for the assessment of wetland carbon sink.The results showed that soil organic carbon storage in the Salix triandroides community was higher in the high water level,while the soil organic carbon storage in the Carex brevicuspis community was higher in the medium water level.In the low and high water levels,the soil organic carbon storages of the Salix triandroides community were higher than those of the Carex brevicuspis community,while in the medium water level,the soil organic carbon storage of the Salix triandroides community was lower than that of the Carex brevicuspis community.The organic carbon density of sediment increased with the increase of water level both in Salix triandroides community and in Carex brevicuspis community,and did not differ significantly between the two communities.The organic carbon density in litters increased firstly and then decreased with the increasing water levels,and was higher in the Salix triandroides community than that in the Carex brevicuspis community.The sources of soil organic carbon in both plant communities were dominated by sediment organic carbon,and supplemented by litter organic carbon.The contribution of sediment organic carbon to the soil organic carbon in the Carex brevicuspis community was higher than that in the Salix triandroides community.These results indicated that in the process of wetland restoration,appropriate vegetation types can be selected according to the water level characteristics to enhance the function of carbon sink.

关 键 词：水位梯度 植被类型 有机碳 泥沙淤积 凋落物 

分 类 号：S153.6[农业科学—土壤学]