中文摘要：

岸边带生态系统对氮元素的去除机理主要包括化学释放含氮气体过程,植物吸收过程和泥沙截留3方面.其中,土壤反硝化释氮是岸边带系统最为重要的生态功能之一.因此,建立适当的岸边带土壤释氮模型（包括土壤反硝化、硝化和氨挥发过程）,对准确评估岸边带生态功能和构建合理的岸边带生态系统具有重要意义.本研究依据岸边带去氮机理,参照已有的土壤释氮模型研究成果,构建了适用于水库库滨带土壤特性的土壤释氮速率估算模型（简称土壤释氮模型）,并以官厅水库库滨带小区为研究对象,对水库库滨带土壤释氮特性进行模拟分析与验证.模型模拟结果表明,在监测期间（6～9月）土壤水分平均含量分别为16.6%、37.3%、43.9%和55.2%的情况下,土壤反硝化释氮速率分别为0、（102.1±59.3）、（169.3±87.6）和（203.2±119.6）mg·m^-2·d^-1（以N计）;硝化速率分别为（233.3±121.4）、（177.9±69.3）、（187.7±75.0）和（166.7±121.9）mg·m^-2·d^-1（以N计）;氨挥发速率分别为（3.00±1.13）、（2.64±1.01）、（2.76±1.04）和（2.51±1.89）mg·m^-2·d^-1（以N计）;总释氮量分别为1.18、33.64、92.50和65.74g（以N计）.同时,结合同步监测的实验数据,应用总量平衡法对模拟结果进行了验证.验证结果表明,实验小区土壤释氮量模拟值与实验值的决定系数（R^2）为0.83,证明了该模型可有效地应用于水库库滨带区域.

英文摘要：

The processes that affect nitrogen removal in a riparian ecological system mainly include soil nitrous gas emission, plant uptake and sediment retention, of which nitrous gas release by soil denitrifieation is one of the most important functions for the riparian system. Therefore, it is critical to build an N removal model including soil denitrification, nitrification and ammonia volatilization to evaluate the riparian ecological functions and practice riparian management. In this work, a nitrous gas release model for the riparian zone was constructed based on a process-mechanlsm. The model includes three submodules： soil nitrification, soil denitrifieation and ammonia volatilization. Based on the pilot experiments carried out in the riparian zone of the Guanting reservoir, the characteristics of soil N removal in the riparian zone were analyzed and the model was calibrated and validated. The findings show that during the experiments （ June to Sep. , 2007 ）, under different soil moisture levels （ 16.63% , 37.26% , 43.92% and 55. 19% ）, the simulated average soll deuitrification rates were 0, （ 102.1 ± 59.3 ）, （ 169.3 ± 87.6） and （203.2 ±119.6 ） mg· m ^- 2· d ^- 1. With the same soil moisture levels, the simulated nitrification rates were （233.3 ± 121.4）, （177.9 ±69.3）, （187.7±75.0） and （166.7 ± 121.9） mg· m ^- 2· d ^- 1; and the ammonia volatilization rates were （ 3.00 ± 1.13 ） , （2.64 ± 1.01 ） , （2.76 ± 1.04） and （ 2.51 ± 1.89） mg· m ^- 2· d ^- 1. Also, under the same conditions, the total N removals were 1.18 g, 33.64 g, 92.50 g and 65.74 g, respectively, during the experiment from June to September. According to the conservation of mass of N in the pilot experiment system, the model was calibrated and validated. The correction analysis between the simulated and monitored values had a coefficient of determination （R^2 ） of 0.82, which indicated the simulated＇resuhs were sound and the model can be applied effectively in the riparian zon