岷江上游干旱河谷不同坡向土壤氮素分异研究

Study of Soil Nitrogen Heterogeneity among Different Slopes in the Semi-arid Areas of Upper Reaches of the Minjiang River

[目的]研究岷江上游干旱河谷不同坡向土壤氮分异特征。[方法]采用野外调查和室内分析相结合的方法,立足于岷江上游山地深林/干旱河谷交错带,对不同坡向土壤氮分异特征进行研究。[结果]阳坡坡面土壤全氮、水解性氮、硝态氮、微生物量氮随海拔降低和土壤剖面的加深而逐渐减少,彼此之间有显著的正相关关系。而在阴坡坡面全氮、水解性氮、硝态氮、微生物量氮含量随海拔降低而逐渐升高,剖面上的变化趋势与阳坡相似,相关分析结果表明,这种氮素形态之间的相关性与阳坡一致。[结论]不同坡向、不同海拔对氮分布有极大的影响。

[Objective]To study soil nitrogen heterogeneity among different slopes in the semi-arid areas of upper reaches of the Minjiang River.[Method]Using the method of combining field investigation and indoor analysis,based on the upper reaches of the Minjiang River deep mountain forest in the arid valley ecotone,soil nitrogen differentiation characteristics of different slopes were studied.[Result]Total nitrogen,hydrolyzable nitrogen,nitrate nitrogen,microbial biomass nitrogen in sunny slope soil decreased with decreasing altitude and soil depth,there was a significant positive correlation between each other,while in shady slopes,total nitrogen,hydrolyzable nitrogen,nitrate nitrogen,microbial biomass nitrogen content decreased gradually with altitude increasing.The variation trend in the profile was similar to that of the sunny slope,and the correlation analysis results showed that the correlation between different nitrogen forms was consistent with the sunny slope.[Conclusion]Different slope directions and altitudes have great influence on nitrogen distribution.