杭州城市湿地沉积物碳、氮垂向分布特征研究

Vertical Distribution of Carbon and Nitrogen in the Sediments of Urban Wetlands of Hangzhou

2012年6月采集了杭州市西溪I期、II期、III期及和睦湿地柱状沉积物样品，研究沉积物中有机碳、全氮含量的垂向分布特征及影响因素。结果表明，西溪湿地I期、II期、III期及和睦湿地柱状沉积物样层理明显，沉积特征变化不大，剖面各层容重随沉积物深度增加均呈“S”型增长趋势；沉积物中有机碳的含量和密度均以0～10 cm层最高，全氮含量均以0～5 cm层较高；有机碳储量大小顺序为西溪湿地III期＆gt;和睦湿地＆gt;西溪湿地I期＆gt;西溪湿地II期；总氮储量大小顺序为和睦湿地＆gt;西溪湿地III期＆gt;西溪湿地II期＆gt;西溪湿地I期。相关分析表明，沉积物中有机碳含量与全氮含量呈显著线性相关，两者均与沉积物深度或容重呈指数式负相关关系。人为扰动明显降低了西溪湿地I、II期沉积物中的碳、氮含量及储存。

Patterns of vertical distribution of total organic carbon and total nitrogen in the sediments of Xixi wetland and Hemu wetland, Hangzhou city and causes for the distribution were studied in June, 2012. Results indicated that all samples of sediment cores had significant bedding layers and did not change in sedimentary characteristics in phases I, II, III of Xixi wetland and Hemu wetland. The depth of sediments increased in a＆quot;S＆quot; shape in all 4 sediment profiles. The content and density of organic carbon were the highest in 0~10 cm layer of each sediment, and the total nitrogen contents were relatively higher in 0~5cm layer, but the order of organic carbon reserves and total nitrogen reserves in the sediments was followed by Xixi wetland phase III＆gt;Hemu wetland＆gt;Xixi Wetland phase I＆gt;Xixi Wetland phase II and Hemu wetland＆gt;Xixi Wetland phase III＆gt;Xixi Wetland phase II＆gt;Xixi Wetland phase I, respectively. Correlation analysis showed that the total organic carbon content was significantly correlated with the total nitrogen content for each sediment core, and the contents of total organic carbon and total nitrogen had exponentially negatively relationship with both sediment depth and sediment bulk density in Phase I, II, III of Xixi wetland and Hemu wetland. Human disturbance significantly reduced the carbon and nitrogen contents in the sediments in Phase I and Phase II of Xixi Wetland.