西宁市湿地沉积物有机碳及碳储量变化研究

Study on changes of organic carbon and carbon storage in wetland sediments in Xining City

关键词:  高寒湿地  沉积物  有机碳  碳储量  环境因子

Key words:  alpine wetland  sedimen  organic carbon  carbon storage  environmental factors

摘要:

开展西宁市湿地沉积物碳储量变化研究，有助于评估西宁市湿地沉积物碳汇能力，可为高原城市湿地保护和修复提供理论依据。本文以西宁市北川河湿地、宁湖湿地和海湖湿地为研究对象，分析不同湿地枯水期和平水期沉积物碳密度和碳储量，探究各湿地沉积物有机碳（TOC）含量与环境因子之间的相关性。结果表明：枯水期北川河湿地、宁湖湿地和海湖湿地不同采样区沉积物有机碳含量均高于平水期的有机碳含量，枯水期和平水期宁湖湿地芦苇区沉积物有机碳含量最高，分别为2.709%和 1.653%，三个湿地不同采样区沉积物有机碳含量均为TOC芦苇区>TOC无植被区＞TOC香蒲区。从垂直分布看，有机碳含量最高值分布在 0-10cm沉积物层，各层沉积物有机碳含量存在显著性差异，随着沉积物深度的增加，沉积物有机碳含量均呈现逐渐降低的趋势。三个湿地不同采样区沉积物碳密度最大的均为芦苇区，碳储量最大的均为无植被区，且枯水期的碳储量均高于平水期，其中宁湖湿地碳密度和碳储量最大，其次为北川河湿地、海湖湿地。西宁市湿地沉积物有机碳含量主要受硝态氮（NO3--N）和含水率变化的影响。总体上，枯水期西宁市湿地沉积物有机碳含量、碳密度及碳储量均高于平水期，宁湖湿地沉积物有机碳含量、碳密度及碳储量最大，可能与不同时期各湿地植被覆盖度、凋落物的分解以及环境因子对湿地水体和沉积物微生物活动的影响有关系。

Abstract:

The study on the change of wetland sediment carbon storage in Xining City is helpful to evaluate the carbon sink capacity of wetland sediment in Xining City, and can provide theoretical basis for the protection and restoration of wetland in plateau city. In this paper, Beichuanhe Wetland, Ninghu wetland and Haihu Wetland in Xining City were selected as research objects to analyze the sediment carbon density and carbon storage of different wetlands during dry season and normal season, and to explore the correlation between the sediment organic carbon (TOC) content and environmental factors. The results show that: The sediment organic carbon content of Beichuanhe wetland, Ninghu Wetland and Haihu wetland in dry season is higher than that in normal season. The sediment organic carbon content of reed area of Ninghu wetland in dry season and normal season is the highest, which is 2.709% and 1.653%, respectively. The sediment organic carbon content in different sampling areas of the three wetlands was TOC reed area >TOC non-vegetated area >TOC cattyma area. From the vertical distribution, the highest value of organic carbon content was distributed in the 0-10cm sediment layer, and there were significant differences in the organic carbon content of sediments in each layer. With the increase of sediment depth, the sediment organic carbon content showed a gradually decreasing trend. The largest sediment carbon density in different sampling areas of the three wetlands is reed area, and the largest carbon storage is non-vegetated area, and the carbon storage in dry season is higher than that in normal season, among which the carbon density and carbon storage of Ninghu wetland are the largest, followed by Beichuan River wetland and Haihu wetland. The organic carbon content of wetland sediments in Xining City is mainly affected by the changes of NO3--N and water content. In general, the organic carbon content, carbon density and carbon storage of wetland sediments in Xining City during dry season were higher than those in normal season, and the organic carbon content, carbon density and carbon storage of wetland sediments in Ninghu Lake were the largest, which may be related to the vegetation coverage of each wetland in different periods, the decomposition of litter, and the effects of environmental factors on the microbial activities of wetland water and sediment.