祁连山典型流域青海云杉林土壤氮磷钾空间变异性研究

Spatial Variability of Soil Nitrogen,Phosphorus and Potassium in Picea crassifolia Forest in the Typical Watershed of the Qilian Mountains,Northwestern China

基于祁连山中段排露沟流域海拔2600~3300 m的带状青海云杉林中0~10、10~20、20~40 cm的土壤TN、TP、TK的测定分析数据,运用经典统计学、地统计学的方法对其土壤TN、TP、TK含量的空间变异特征及空间分布特点进行研究。结果表明,1)研究区内土壤TN含量为1.34~8.98 g·kg^(-1),土壤TP含量为0.46~1.12 g·kg^(-1),土壤TK含量为9.75~24.17 g·kg^(-1);不同土层土壤TN、TP、TK变异系数为13.26%~35.47%,均属中等程度变异;2)10~20 cm TP的块金系数为0.617,属于中等空间相关性,其余块金系数均<0.25,具有强烈空间相关性;3)克里格插值结果显示,土壤TN、TP含量随海拔的升高而升高,土壤TK含量随海拔升高而降低。不同土层土壤TN、TP、TK含量的空间变异性特征,与海拔、土壤母质及云杉林枯落物等结构性因素有关。

We conducted a research on soil total nitrogen,total phosphorus and total potassium based on the measurement and analysis of the data from the three soil layers at the depths of 0-10,10-20,and 20-40 cm from Picea crassifolia forest,located at altitudes of 2600-3300 m in the Pailugou watershed in the middle portion of the Qilian Mountain.The spatial variations and distribution characteristics of soil total nitrogen,phosphorus,and potassium were analyzed by adopting classical statistics and geostatistics methods.The results showed that 1)the contest ranges of soil total nitrogen,phosphorus,and potassium were 1.34-8.98,0.46-1.12,and 9.75-24.17 g·kg^(-1),respectively,with the variation coefficients of 13.26%-35.47%,which belonged to medium level.2)The Nugget coefficient of soil total phosphorus at the depth of 10-20 cm was 0.617,which belonged to medium spatial correlation,and the other Nugget coefficients were less than 0.25,indicating significant solid spatial correlation.3)Kriging interpolation results showed that the contents of total soil nitrogen and phosphorus increased with the increase of altitude,and the content of total soil potassium decreased with the increase of altitude.The spatial variability of soil total nitrogen,phosphorus and potassium contents in different soil layers was related to structural factors such as altitude,soil parent material and spruce forest litter.