外源添加对黄河流域典型湿地土壤矿化及硝化的影响

以黄河上游若尔盖湿地（A土）、中游包头南海湿地（B土）、下游黄河三角洲湿地（C土）为研究对象，分别选用NH₄NO₃和葡萄糖作为外加氮源和碳源，采用28 d恒温培养法，研究了外源添加对黄河流域典型湿地土壤日平均碳矿化速率（C_average）、净氮矿化速率（NN_min）、净硝化速率（NN_nitri）的影响。结果表明，湿地类型对土壤碳、氮矿化及硝化速率影响显著，土壤理化性质差异是主要影响因素。外源碳添加对不同类型湿地C_average均显著提高，且对A土促进作用最显著；外源氮添加对C_average影响不显著。外源碳、氮添加水平对不同类型湿地NN_min的影响存在显著差异。低水平碳源添加显著抑制C土NN_min，但对A土和B土NN_min影响不显著；高水平碳源添加对不同类型湿地NN_min均表现出显著的抑制作用。低水平氮源添加对不同类型湿地NN_min影响不显著；高氮添加显著抑制B土、C土NN_min，但对A土NN_min影响不显著。外源碳、氮添加对不同类型湿地NN_nitri的影响不显著。

Effects of exogenous addition on soil mineralization and nitrification of typical wetlands in the Yellow River Basin

Taking Zoige Wetland (soil A) in the upper reaches of the Yellow River, Baotou Nanhai Wetland (soil B) in the middle reaches, and the Yellow River Delta Wetland (soil C) in the lower reaches as the research objects, NH₄NO₃ and glucose were used as external nitrogen and carbon sources, respectively, and a 28 d constant temperature cultivation method was used. The effects of exogenous addition on daily average carbon mineralization rate (C_average), net nitrogen mineralization rate (NN_min), and net nitrification rate (NN_nitri) of typical wetland soil in the Yellow River Basin were studied. The results show that wetland types have significant effects on soil carbon and nitrogen mineralization and nitrification rates, and differences in soil physical and chemical properties are the main influencing factors. Carbon addition significantly increased C_average of different wetland soils and the most significant promotion was exerted on soil A. However, nitrogen addition had no significant effect on C_average. Addition level had significant influence on NN_min. Low level carbon addition significantly inhibited NN_min of soil C while had no significant effect on that of soil A or soil B. High level carbon addition significantly prevented NN_min of different wetland soils. Low level nitrogen addition had no significant effect on NN_min. High level nitrogen addition significantly inhibited NN_min of soil B and soil C, while had no significant effect on soil A. Exogenous addition had no significant effect on NN_nitri.