不同高寒草甸土壤碳氮稳定同位素和密度的差异
发布时间：2018-11-04 09:45
【摘要】：为了解不同类型高寒草甸土壤碳氮稳定同位素和密度的差异,采用稳定同位素质谱仪Isoprime100对采自黄河源区不同高寒草甸覆被条件下0~30cm土壤进行了碳氮稳定同位素组成特征和密度分析。结果表明,高寒草甸土壤δ13 C值介于-25.42‰~-24.20‰之间,δ15 N值介于3.37‰~4.69‰之间,显著高于大气δ15 N值。δ13 C值和δ15 N值均随土壤深度加深而增大。人工草地土壤δ13 C值显著低于轻度和重度退化草甸(P0.05),而δ15 N值显著高于轻度和重度退化草甸(P0.05)。土壤碳氮比最小值为7.89,最大值为9.97,平均碳氮比为8.71。土壤有机碳含量和全氮含量呈正相关(P0.01),二者的回归方程为y=0.0963x+0.0336(R2=0.9619)。轻度退化草甸、严重退化草甸和人工草地0~30cm土壤碳密度依次为7.14、6.67和6.46kg/m2;全氮密度依次为0.83、0.77和0.75kg/m2。植物吸收、生长有利于12 C和14 N的输出,而将较重的13 C和15 N留在了土壤中。人工草地植物生长势强,形成的地上生物量多,吸收了较多的土壤氮素14 N,导致土壤15 N升高。植被退化或种植人工草地均可导致土壤碳氮密度的显著降低,这种变化主要发生在0~20cm土层。
[Abstract]:In order to understand the differences of carbon and nitrogen stable isotopes and densities in different types of alpine meadow soils, Carbon and nitrogen stable isotopic compositions and densities of 0~30cm soils collected from different alpine meadow cover conditions in the source region of the Yellow River were analyzed by means of stable isotope mass spectrometer (Isoprime100). The results showed that the 未 13 C and 未 15 N values of alpine meadow soil ranged from -25.42 鈥，
本文编号：2309463
[Abstract]:In order to understand the differences of carbon and nitrogen stable isotopes and densities in different types of alpine meadow soils, Carbon and nitrogen stable isotopic compositions and densities of 0~30cm soils collected from different alpine meadow cover conditions in the source region of the Yellow River were analyzed by means of stable isotope mass spectrometer (Isoprime100). The results showed that the 未 13 C and 未 15 N values of alpine meadow soil ranged from -25.42 鈥，
本文编号：2309463
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