太子河源头水源涵养林不同植被类型矿质态氮流失特征及其对环境因子的响应

Mineral Nitrogen Loss in Different Types of Vegetation and Its Response to Environmental Factors in the Water Conservation Forest in the Headstream of Taizi River

以太子河源头水源涵养林为研究对象,分析不同植被类型地表径流和壤中流的氮流失特征,运用冗余分析和偏冗余分析对氮流失特征与环境因子之间的关系进行分析,并对其主要影响因子进行定量分解,探寻太子河源头水源涵养林氮流失特征的关键影响因子。结果表明:不同植被类型地表径流和壤中流硝态氮是氮流失的主要形态,地表径流硝态氮的浓度是铵态氮浓度的1.5倍,壤中流硝态氮的浓度是铵态氮浓度的20.5倍。无论是地表径流还是壤中流铵态氮和硝态氮流失浓度的大小顺序均为人工林>杂木林>次生林。受径流量和壤中流量的影响,铵态氮流失量表现为次生林最大,硝态氮流失量表现为人工林最大。土壤物理性质和土壤化学性质是影响氮流失浓度的关键因子,分别能解释氮流失浓度总变异的46.36%和16.42%。地形水文因子和植被特征是影响氮流失量的关键因子,分别能解释氮流失量总变异的22.85%和15.09%。而地形水文因子、植被特征、土壤物理性质、土壤理化性质4者混合作用在对氮流失特征中也起到了重要影响,分别能解释氮流失浓度和流失量总变异的36.03%和51.36%。

The characteristics of mineral nitrogen loss through surface flow and interflow in different types of vegetation in a water conservation forest were analyzed in the headstream of Taizi river.To explore the limiting factors which affect nitrogen loss,redundancy analysis and partial redundancy analysis were applied to study the relationship between nitrogen loss and environmental factors,and quantitative analysis was applied among the main influential factors.The results showed that nitrate nitrogen was the main form of nitrogen loss in both the surface flow and interflow.The concentration of nitrate nitrogen was 1.5times more than the ammonium nitrogen in the surface flow and 20.5times in the interflow.Whether in the surface flow or interflow,ammonium and nitrate concentrations were in the order of plantation forest hardwood forestsecondary forest.Owing to the effects of surface flow and interflow,the amount of ammonium loss was the largest in secondary forest;the amount of nitrate loss was the largest in plantation forest.Soil physical and chemical properties were the main influential factors of the concentration of nitrogen loss,with their effects accounting for 46.36%and 16.42% of the total explanation,respectively.Geomorphology-hydrology factors and vegetation types were the main influential factors of the amount of nitrogen loss,with their effects accounting for 22.85% and 15.09% of the total explanation,respectively.The mixed effects of hydrological factors,vegetation characteristics,soil physical properties,soil chemical properties on nitrogen loss charac-teristics also played an important role,accounting for 36.03% and 51.36% of the total explanation for the concentration and the amount of nitrogen loss,respectively.