摘要
明确农牧交错带草坡地土壤-植物系统磷素分布特征对于草坡地生态系统磷素管理、空间分布和磷素流失预测具有重要科学意义。本研究针对黄土高原农牧交错带本氏针茅坡地,分析了草坡地土壤-植物系统磷素沿坡面的分布特征,并且从不同空间尺度研究了土壤-植物系统磷素的空间结构特征,以揭示农牧交错带草坡地土壤-植物系统磷素分布规律。结果表明,随坡位的降低,草坡地植物生物量、植物磷素含量和储量均逐渐增加,土壤全磷和速效磷含量在坡上部和坡中部相近,且均低于坡底部;这些变量的变异系数均以坡底部最小。植物磷素含量和土壤全磷的变异系数由坡顶向下依次为34.25%、25.98%、10.02%和24.05%、15.27%、10.85%,表明坡底部土壤-植物系统磷素分布相对均匀。各变量的最佳拟合模型在3个分析尺度上均保持一致,植物生物量和土壤速效磷的最佳拟合模型为指数模型,土壤全磷以球状模型拟合效果最佳,而植物磷素以高斯模型拟合效果最好。随分析尺度的增加,块金常数、块金效应逐渐增大。植物磷素含量在5、10、15 m 3个尺度上的块金常数和块金效应依次为0.010、0.010、0.011和7.9、8.5、8.9,即样点间的空间依赖性逐渐减弱,空间相关性减弱。这表明农牧交错带草坡地土壤-植物系统磷素在不同尺度上空间结构比较稳定,属中等或强空间相关性,其空间变异主要来源于结构性因素。
Understanding the phosphorous distribution of plantsoil system in a stipa bungeana slope land in the agro-pastoral transitional zone is fundamental for managing phosphorous and predicting phosphorous distribution and loss in slope lands. In this study, the spatial distribution of phosphorous in plant and soil along a stipa bungeana slope in the agro-pastoral transitional zone of the Loess Plateau was analyzed. Three spatial scales were used to analyze the spatial structure of phosphorous along slopes. The results show that the plant biomass, phosphorous content and amount in plant and soils are increased with the decreases of slope position and the variation coefficients of these variables are smaller in the low position than those in the middle and up position. The variation coefficients of phosphorous concentrations in plants and the total phosphorous in soils from the up position to the low position are 34.25%, 25.98%, 10.02% and 24.05%, 15.27%, 10.85%, respectively. The exponential model is the best fit model for plant biomass and soil available phosphorous, spherical model for soil total phosphorous, and Gaussian model for plant phosphorous, respectively. With the enlargement of the analysis scale, the values of C0 and C0/(C0+C) are increased, showing a decreased spatial dependence of sampling sites and weak spatial correlations. The C0 and C0/(C0+C) of phosphorous concentration in plants are 0.010, 0.010, 0.011, and 7.9, 8.5, 8.9, respectively, at the analytical scales of 5, 10, and 15 m. These results indicate that phosphorous in plant and soil has relatively stable spatial structure at different spatial scales which belongs to medium or strong spatial correlations, and its spatial variation mainly comes from structural factors.
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2013年第5期1192-1199,共8页
Journal of Plant Nutrition and Fertilizers
基金
国家自然科学基金项目(40901145)
西北农林科技大学基本科研业务费(QN2011147)
中国科学院西部行动计划项目(KZCX2XB3-13)资助
关键词
磷素空间分布
土壤-植物系统
本氏针茅坡地
农牧交错带
phosphorous spatial distribution
plant and soil system
stipa bungeana slope land
agro-pastoral transitional zone