河岸湿地土壤氧化亚氮产排通量对硝酸盐含量、土壤湿度的响应机制研究

项目名称： 河岸湿地土壤氧化亚氮产排通量对硝酸盐含量、土壤湿度的响应机制研究

项目编号： No.41301081

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 天文学、地球科学

项目作者： 姚允龙

作者单位： 东北林业大学

项目金额： 26万元

中文摘要： 长期接受氮输入的河岸湿地是重要的脱氮生物反应器，也是氧化亚氮的热点排放区，其氧化亚氮的排放通量问题是全球变化研究的重要议题之一。由于土壤环境和水文条件经常波动，河岸湿地氧化亚氮排放存在较大时空差异，估算其排放通量存在不确定性。本项目选择三江平原的七星河湿地自然保护区为研究区，从一定气温条件下，河岸湿地氧化亚氮排放通量的空间差异是由土壤硝酸盐浓度的不同造成，每个点上的时间排放差异是由土壤湿度的不同所造成的科学假设出发，根据河岸区的水文地貌特征和硝酸盐梯度设定野外观测剖面，利用原位观测和室内原状土柱控制实验的方法，分析不同土壤深度氧化亚氮浓度对其地气界面通量的影响；探讨硝酸盐浓度和土壤湿度对河岸湿地氧化亚氮产生和排放的影响机制；建立长期氮输入下，土壤环境为影响因素的河岸湿地氧化亚氮排放规律广义可加模型（GAM），揭示河岸湿地氧化亚氮的排放规律，提高北方温带河岸湿地氧化亚氮排放通量的估算精度。

中文关键词： 河岸湿地；氧化亚氮；湿地土壤；硝酸盐；通量

英文摘要： Chronically nitrate-loaded riparian wetland is a important denitrificatiion bioreactor, but also emit relatively high nitrous oxide emissions compared to many other ecosystems,which was classified as hotspot for nitrous oxide emission at the landscape scale.The problem of nitrous oxide emssion of riparian wetland is one of important issues?of Globle Change. Heterogeneity in nitrous oxide fluxes is expected in natural systems, especially those maintaining variable soil conditions and seasonally changing hydrology,such as riparian wetland.With the current knowledge, detailed prediction of nitrous oxide emission from riparian wetland was subject to large uncertainty.?Detailed predictions of emissions at large scales are therefore very hard to make.We took Qixing River National Nature Reserve as the research area, which located in Naoli river watershed of Sanjiang plain，Northeast China.At a certain temperature condition, We hypothesized that spatial differences in nitrous oxide fluxes across the riparian zone would be most strongly related to the concentration of nitrate supplied from different sources (agricultural field and stream), whereas temporal induced spatial variability at each site would be driven by changes in soil moisture.The observer profile and points will be difined by the characters of hydrogeomorph

英文关键词： Riparian wetland；Nitrouse Oxide；Soil；Nitrate；fluxes