纳帕海湿地退化对碳氮积累影响的研究

Research on the Effect of Wetland Degradation on the Accumulation of Organic Carbon and Total N in Napahai

以纳帕海原生沼泽湿地作为参照，选择人为干扰下的草甸作为研究对象，研究人为干扰对纳帕海湿地土壤碳氮积累的影响。结果表明，原生沼泽演化为草甸后，土壤容重增加，土壤含水量降低；原生沼泽的C／N值较大；纳帕海湿地土壤的有机碳和氮含量在空间分布上是不平衡的，且土壤全氮空间分布呈现与有机碳相同的趋势，在垂直空间分布上，土壤有机碳0～20cm表层与20～40cm下层相差15倍，土壤全氮0～20cm表层与20～40cm下层相差8倍；在水平空间分布上，0～20cm表层的有机碳相差7倍，20～40cm下层的有机碳相差15倍；0～20cm表层的全氮相差5倍，20～40cm下层的全氮相差8倍，并经估算，表明纳帕海湿地退化为草甸后，导致有机碳的损失约为4．44×10^9t，损失率为89．4％，氮的损失约为2．43×10^8t，损失率为79．67％，损失的碳氮以CO2、C地和NO2等温室气体的形式释放到大气中，加重温室气体对全球气候的影响。

Taking the prinmary swamp wetlands in Napahai as the reference, choosing meadow under jamming as the study object, the effects of jamming on the accumulation of carbon and nitrogen in Napahai wetland were studied. The results showed that the weadow was evolved from the primary swamp, the density of soil increased and water content reduced. C/N was high in the primary marsh. The organic matter and total N in soil were not balanced in the spatial distribution. The distribution of total N in soil had the same trend with the organic matter. In perpendicular space distribution, organic matter in 0-20cm soil layer was 15 times as much as 20-40 cm layer. Total N in 0-20cm soil layer was 8 times as much as 20-40 cm soil layer. In the horizontal spatial distribution, there was 7 times difference of organic matter in 0 - 20 cm surface layer and there was 15 times difference of organic matter in 20 - 40 cm soil layer. There was 5 times difference of total N in 0 - 20 cm surface layer and 8 times difference in 20 - 40 cm soil layer. Through budgets on the degeneration of Napahai wetland, the carbon stock losses reached 4.44 × 109 t and the loss percentage was 89.4%. The nitrogen stock losses reached 2.43 ×10s t and the loss percentage was 79.67%. The lost carbon and nitrogen released into air in a form of greenhouse gases, such as CO2, CH4 and NO2. These actions increased the inmpact of greenhouse gases for global climate.