三峡库区不同植被对土壤碳氮磷生态化学计量学特征影响.doc

三峡库区不同植被对土壤碳氮磷生态化学计量学特征的影响 　　摘要：土壤碳氮磷生态化学计量特征是陆地生态系统生物地球化学循环偶联的关键指标之一。以湖北宜昌点军区3种植被类型（柏树地、橘树地、菜地）的土壤作为研究对象，对土壤碳氮磷及其生态化学计量学进行了研究，探讨不同植被覆盖对土壤碳氮磷之间的关系与影响。结果表明，不同植被覆盖显著改变土壤碳氮磷含量，柏树地的土壤有机碳和全氮的含量显著大于柑橘地和菜地，而菜地和柑橘地土壤有机碳和全氮含量之间无显著差异，菜地的全磷含量最大，其次是橘树地，柏树地最小。3种植被覆盖的土壤碳氮比之间无显著差异，但是柏树地的土壤碳磷比最大，其次是橘树地，菜地的最小；土壤氮磷比是柏树地显著大于橘树地和菜地，而菜地和橘树地之间无显著差异。表明三峡库区土壤碳氮偶联反应，而氮磷之间以及碳磷之间并未发生偶联反应。相关性分析的结果表明，土壤碳磷比是柏树地橘树地菜地。碳磷比、氮磷比与有机碳之间的相关性大于全氮和全磷，表明土壤碳磷比和氮磷比主要受到碳的影响 关键词：不同植被；碳氮比；碳磷比；氮磷比；生态化学计量学特征 中图分类号：S153.6+1；Q948 文献标识码：A 文章编号：0439-8114（2016）14-3566-03 DOI：10.14088/j.cnki.issn0439-8114.2016.14.009 Abstract： Soil carbon （C），nitrogen （N） and phosphorus （P） stoichiometry is a critical indicator of biogeochemical coupling in terrestrial ecosystem. Taking 3 vegetation types（cypress，tangerine trees and vegetable） soil in Dianjun Yichang command of Hubei province as the research object，soil carbon，nitrogen and phosphorus and its ecological chemometrics were studied，and the relationship and influence of different vegetation on soil carbon，nitrogen and phosphorus were discussed. The results showed that although the contents soil organic C（OC） and total nitrogen（TN） of cypress site was significantly higher than those of vegetable site and citrus tree site，which were not significant difference，total phosphorus（TP） followed the order：Vegetable sitecitrus tree site cypress site. Although soil C/N had no significant diffence among three vegetation cover，C/P followed as cypress sitecitrus tree sitevegetable site，the trend of N/P was similar to OC and TN. It was suggested that soil C and N remained coupled whereas C and P，N and P become decoupled. The correlation analysis showed the relationship between soil C/P，N/P and OC was higher than those between soil C/P，N/P and TN，TP，indicating that C/P and N/P were mainly affected by soil organic carbon. Key words： different vegetation； C/N； C/P； N/P； stoichiometry 土壤碳氮磷是地球化学养分循环的核心，驱动着土壤内其他养分元素的循环和转化，在元素平衡中发挥着重要的作用[1，2]。同时土壤碳氮磷又是目前全球变化中碳循环和生物地球化学循环的研究热点[3