张雪冰+闫玉琴+陈国静+申卫博+王国栋

摘要：通過对陕西毛乌素沙地典型湖滨带湿地有机碳和氮素的空间分布特征进行研究，为探讨湿地生态系统如何在沙化环境下发挥其特有的功能提供科学依据。在巴吓采当湖泊湖滨带A～F类型区采集土壤，测定土壤的有机碳、全氮、有机氮、硝态氮和铵态氮等指标。利用方差分析、Spearman相关性分析和主成分分析等方法分析对湖滨带有机碳、氮素空间分布特征进行研究。土壤表层0～10 cm的有机碳和全氮含量随水位升高呈增加趋势。除了铵态氮外，有机碳、全氮、有机氮和硝态氮含量垂直分布上随着土壤深度增加呈降低趋势。 土壤有机碳、全氮含量分别与全磷、土壤容重、含水率、水位显著相关。铵态氮和全磷、含水率、土壤容重、全氮、有机碳和水位等显著相关。硝态氮与微生物生物量碳、氮的相关系数分别为r=0.637和r=0.617（中度正相关）。有机碳及氮素的含量与土壤粘粒含量相关性不高。主成分分析提取3个主成分，累积贡献率达76.15%。土壤全磷、土壤含水率、土壤容重和水位是影响湖滨带土壤有机碳、氮素空间分布的主要因子。

关键词：湖滨带；有机碳 ；全氮； 分布特征；水位

中图分类号：S153.6 文献标识码：A 文章编号：1672-1683（2017）04-0087-07

Abstract：This study was aimed to analyze the spatial distribution characteristics of soil organic carbon and nitrogen in soils from typical lake littoral wetland of Mu Us Sandland in Shaanxi Province and to provide a scientific basis for studying the way in which wetland ecosystem plays its special function in desertified environment.We collected soil samples from A-F zones along Baxiacaidang Lake and measured the contents of soil organic carbon，total nitrogen，organic nitrogen，nitrate nitrogen，and ammonium nitrogen.Soil organic carbon and nitrogen distribution were analyzed by ANOVA，Spearman correlation coefficients，and principal components analysis.At the depth of 0-10 cm，the contents of soil organic carbon and total nitrogen would increase with the increasing water level.Regarding vertical distribution，except for ammonium nitrogen，the contents of soil organic carbon，total nitrogen，organic nitrogen，and nitrate nitrogen would all decrease with the increasing soil depth.The contents of soil organic carbon and total nitrogen were significantly and positively correlated with total phosphorus，volume weight of soil，soil moisture content，and water level.The content of soil ammonium nitrogen was significantly and positively correlated with total phosphorus，soil moisture content，volume weight of soil，total nitrogen，organic carbon，and water level.Between nitrate nitrogen and microbial biomass carbon，the correlation coefficient was 0.637；between nitrate nitrogen and microbial biomass nitrogen，the correlation coefficient was 0.617.The contents of soil organic carbon and nitrogen were not significantly correlated with soil clay content.The cumulative contribution rate of the three principal components was 76.15%.Total phosphorus，soil moisture content，volume weight of soil，and water level were major factors which can affect the spatial distribution of soil organic carbon and nitrogen distribution.

Key words：lake littoral zone；soil organic carbon；total nitrogen；distribution characteristics；water level

湿地是自然界具有最富生物多样性的生态景观之一，并且是人类赖以生存的环境[1]，也是陆地和水生生态系统间的过渡带，具有极高的资源开发价值和环境调节功能[2]。全球湿地有机碳储量约为450 Gt（1 Gt=109 t），占陆地生态圈表层碳总储量的20%～30%[3]，但湿地面积仅占陆地总面积的4%～6%[4]。……