贵州省旱地黄壤Zn和有机质的空间异质性特征

Spatial heterogeneity of Zn and organic matter in dryland yellow soil of Guizhou Province

探究黄壤Zn和有机质的空间分布特征及其变异规律,分析环境因子对黄壤Zn和有机质空间分异的影响,对贵州省山地复杂环境下土壤资源的科学管理和可持续利用具有重要意义.基于130914个野外采样点,综合运用多种地统计学与传统统计学的方法,分析了贵州省旱地黄壤Zn和有机质的空间变异特征及其驱动因子.结果表明:(1)贵州省旱地黄壤Zn的平均含量略低于全国土壤Zn的平均含量(100 mg·kg^(-1)),处于中等水平,而有机质含量则较为丰富;变异系数表明两者均属于中等程度的空间变异.(2)黄壤Zn和有机质均存在显著的空间自相关性,呈聚集分布,其中以Zn的Moran's I指数更大、自相关程度更强;两个养分的最优理论模型均为指数模型,且块基比均介于25%~50%,具有中等程度的空间相关性,但结构性因素的作用更大;有机质的分形维数较Zn要高,其空间格局更复杂,对尺度的依赖性大.(3)Zn的高值区主要集中在西部和西北部地区,低值区多位于东南部和南部地区;有机质高值区沿西北东南带斜线分布,而低值区则沿东北西南方向与高值区呈现交叉分布的格局.(4)空间自相关分析和方差分析表明,选取的7个环境因子均对黄壤Zn和有机质的空间变异具有不同程度的影响,其中,高程和NDⅥ与两者的相关性更强.

It is of great significance for scientific management and sustainable utilization of soil resources in complex mountainous environment of Guizhou Province to explore the spatial distribution characteristics and variation rules of Zn and organic matter in dryland yellow soil and analyze the influence of environmental factors on spatial differentiation of Zn and organic matter in yellow soil.Based on 130914 field sampling sites,the spatial variation characteristics and driving factors of Zn and organic matter in dryland yellow soil in Guizhou Province were analyzed by using multiple geostatistics and traditional statistical methods.The results showed that:(1)The average Zn content of dryland yellow soil in Guizhou province was slightly lower than the average Zn content of soil in China(100 mg·kg^(-1)),which was at a medium level,while the organic matter content was relatively rich.The coefficient of variation shows that both of them belong to the medium degree of spatial variation.(2)Zn and organic matter in the yellow soil showed significant spatial autocorrelation and aggregation distribution,and the"Moran's I"index of Zn was larger and the degree of autocorrelation was stronger.The optimal theoretical models of the two nutrients were both exponential models,and the nugget coefficient was between 25%~50%,showing moderate spatial correlation,but the structural factors played a more important role.The fractal dimension of organic matter is higher than that of Zn,and the spatial pattern of organic matter is more complex and has greater scale dependence.(3)The high value region of Zn is mainly concentrated in the western and northwestern regions,while the low value region is mainly located in the southeastern and southern regions.The high value of organic matter distributed diagonally along the northwest and southeast zone,while the low value distributed diagonally along the southwest direction and the high value zone.(4)Spatial autocorrelation analysis and variance analysis showed that the seven environmental factors had different effects on the spatial variability of Zn and organic matter in yellow soil,among which elevation and NDⅥwere more strongly correlated with them.