【摘要】 在科尔沁典型沙质草地 ,连续放牧 4年后对不同放牧强度的 4个样区中土壤颗粒组分、土壤养分含量 (有机碳和全氮 )进行了样方调查。通过统计学分析、秩相关系数和分维数等方法 ,分析了这些土壤指标在各样区的相关性和变化趋势。结果表明 ,(1)各样区土壤有机碳、全氮之间呈极显著正相关 ,并且二者与土壤中粘粒含量极显著正相关 ,与沙粒含量极显著负相关 ;(2 )放牧区土壤颗粒组分、土壤养分含量 (有机碳和全氮 )的分维数小于封育对照区。分析认为 ,在科尔沁沙质草地放牧强度应保持在低牧水平 ,更高的放牧强度将导致土壤某些性质发生大的改变更多还原

【Abstract】 Four plots with different grazing intensities,i.e.high grazing(6 sheep·hm -2 ,H),moderate grazing(4 sheep·hm -2 ,M),light grazing(2 sheep·hm -2 ,L)and control(0 sheep·hm -2 ,C)were settled in Horqin sandy pasture.After four years of successive grazing,soil granule content,organic carbon and total nitrogen were measured respectively in each plots.Through classical bio-statistics,rank correlation coefficient and fractal dimension,the main results were as follows:(1)Organic carbon and total nitrogen of soil in 4 plots always expressed extremely significant positive correlation with each other,and both were extremely significantly positively correlated with clay content and negatively with sand content.(2)The fractal dimension values of soil granule content,soil nutrients(organic carbon and total nitrogen)in grazing plots(H,M,L)were always larger than equivalent values in control plot.By comparing the fractal dimension values in 4 plots,it was suggested that grazing under light intensity would give less,even no influence on soil,while more intense grazing(like H and M)would change the soil characteristics patently, thus possibly resulting in desertification in Horqin sandy pasture.更多还原