不同放牧模式下高原鼠兔洞口的空间分布格局变化

2019年4-11月,在四川省若尔盖县选取全年禁牧、冬季放牧、全年放牧3种放牧模式样地,对高原鼠兔(Ochotona curzoniae)洞口的数量、空间分布格局变化及影响因子进行了研究.计算平均最近邻指数和S2/m比值来分析样方(10m×10m)和样地水平下的空间分布格局,通过非参数检验评估空间分布格局在不同放牧模式...

Spatial pattern of plateau pika burrows under different grazing modes

We studied the impacts of grazing on the number and spatial patterns of plateau pika(Ochotona curzoniae) burrows in Zoige County of Sichuan Province, China from April to November, 2019.The grazing mode was categorized as grazing prohibition(GP), winter grazing(WG) and year-round grazing(YG).The average nearest neighbor ratio and the S²/m value(the ratio of variation to mean) were respectively used to assess the spatial patterns of burrows within quadrats(10 m×10 m) and at a larger scale within plots.A nonparametric test was used to evaluate differences in spatial patterns between grazing modes and investigation months.Our results showed that:(1) the total and available burrow numbers of plateau pika were significantly different between grazing modes, and WG plots had the highest number.The number of burrows in the WG plots and YG plots differed significantly between months.(2) There were significant differences in the spatial patterns of burrows between grazing modes in the scale of quadrat and plot.The spatial patterns of all burrows and available burrows showed different distributions.(3) The height and coverage of vegetation were correlated with the number and spatial patterns of pika burrows.(4) The total burrow number was positively correlated with the average nearest neighbor ratio.Our study indicated that grazing mode can affect the spatial patterns of plateau pika and subsequently population dynamics.The utilization and spatial pattern of pika burrows are highly influenced by the height and coverage of vegetation near and around burrows.