川西北高寒沙地不同大小高山柳对土壤氮素的影响

为揭示不同大小高山柳灌丛对高寒半固定沙地土壤氮素的影响,本研究选取川西北红原县沙化治理典型示范区内两组不同大小的高山柳灌丛,研究分析其内外土壤氮素的空间异质性,表层土壤含水量及pH变化规律。研究结果表明,高山柳灌丛内部土壤含水量高于边缘和外部;而高山柳灌丛内部土壤pH均低于灌丛边缘和外部;灌丛内部土壤全氮、碱解氮、铵态氮和硝态氮含量均显著高于灌丛外部(P<0.05),其中,大高山柳灌丛全氮最高达0.301 g/kg,碱解氮达24.75 mg/kg;而高山柳灌丛内部土壤亚硝态氮含量低于外部。以上结果表明,高山柳灌丛在生长过程中对养分有富集作用。

Effect of Salix cupularis shrubs on soil nitrogen in the alpine sandy land of Northwest Sichuan

In this study,we evaluated the effect of Salix cupularis shrubs on the spatial heterogeneity of soil nitrogen,soil water content,and soil pH in the alpine sandy land of Northwest Sichuan,China.The soil water content was higher inside shrub canopies than outside.However,the soil pH was higher outside of shrub canopies than inside.Soil total nitrogen,available nitrogen,ammonium nitrogen,and nitrate nitrogen contents were significantly higher inside the shrub canopies than outside (P＜0.05).Soil nitrite nitrogen was higher outside of shrub canopies than inside.These results indicate that the presence and distribution of S.cupularis shrubs can affect the nutrient patterns in soil.