利用样方法及GS+软件和地统计学分析方法对年荒漠草原植物种在不同放牧压下的空间异质性分布进行了研究。结果表明:不同放牧压对荒漠草原物种空间分布有明显影响。整个试验区植物种为38种。SA2(春季零放牧、夏季适度放牧和秋季重度放牧)处理区植物种数最多为10种。家畜选择性采食及践踏等随机因素引起的空间变异在SA2处理区中较小,在SA5(放牧季皆为适度放牧)处理区较大。植物种分布在不同放牧组合下存在强烈的空间自相关性,SA1(春季零放牧、夏季重度放牧及秋季适度放牧)处理区与SA5处理区空间自相关性表现强于SA2、SA3(放牧季皆为重度放牧)区和SA4(春夏季重度放牧、秋季适度放牧)处理区。SA3处理区分形维数最高,空间分布格局简单,空间依赖性强,空间结构性好;相反SA1分形维数最低,空间分布格局相对复杂,随机因素引起的异质性占有较大的比重。
Plant species were analyzed using GS + software and methods of statistical analysis under different grazing intensities on August 2011.The results were as follows: there was significant effect on spatial distribution of plant species under different grazing intensity.Total plant species of test area were 38.In test SA2(zero-grazing in spring,moderate grazing in summer and severe grazing in autumn) there had the maximum species of 10.Spatial variability caused by random factors was the least in test SA2 while the most in SA5(grazing seasons were all moderate grazing).Plant species in different grazing intensities had strong spatial autocorrelation which in test SA1(zero-grazing in spring,severe grazing in summer,moderate grazing in autumn) and SA5 were stronger than that in SA2、SA3(grazing seasons were all severe grazing) and SA4(severe grazing in spring and summer,moderate grazing in autumn).A higher fractal dimension showed in test SA3 and the spatial distribution pattern was simple,the spatial structure was good;however,fractal dimension in SA1 was the lowest,spatial distribution pattern was relatively complex which accounted for a large proportion in spatial heterogeneity caused by random factors.