Abstract

This case study examined the effect of grazing exclusion on the soil and vegetation characteristics to provide support for the restoration of the degraded desert steppe rangelands of the Arshagh ecoregion. Six sampling sites were selected (three overgrazed and three not grazed sites) from the ecoregion. Vegetation sampling (1 m² area at 10 intervals) was carried out along 18 pieces of 90 m long transects. Soil samples were collected from the plots at the beginning, middle, and end of each transect from 0–15 cm depths and then combined to get one sample per transect. Differences between vegetation and soil properties of the grazing exclusion and overgrazed sites were analyzed using the t-test statistic. Species richness index (2.32), the diversity index (1.87), and plant cover (69.46%) were maximum at sites after 20-years of grazing exclusion. All species of plant functional types at the exclusion sites were significantly (p < 0.05) different from those at the overgrazed site. Total aboveground net primary production was greater at the exclusion sites (56.50 g/m²) than at the overgrazed sites. Soil pH was significantly (p < 0.05) higher at the exclusion site than at the overgrazed sites. Electrical conductivity was significantly higher at the overgrazed sites than at the exclusion sites. These results imply that livestock exclusion plays an important role in such vegetation parameters as the diversity, cover and soil properties of degraded rangeland ecosystems. Moreover, grazing exclusion in Arshagh rangelands may be a promising management option for the restoration of such rangelands.

摘要

本案例研究考察了放牧对土壤和植被特征的影响，为恢复阿尔沙生态区退化的荒漠草原牧场提供了支持。从生态区域中选择了六个采样点（三个过度放牧和三个未放牧的站点）。沿着18个长90 m的样条进行了植被采样（每间隔1 m ^2的面积为10个间隔）。在每个样带的起点，中部和终点，从0-15 cm深度的样地中收集土壤样品，然后合并以获得每个样带一个样品。利用t分析了放牧场和过度放牧场的植被和土壤性质的差异。测试统计。放牧20年后，地点的物种丰富度指数（2.32），多样性指数（1.87）和植物覆盖率（69.46％）最大。排斥位点的所有植物功能类型物种 与过度放牧位点的植物均具有显着差异（p <0.05）。排斥地点的地上净初级生产力总量（56.50 g / m ²）大于过度放牧的地点。土壤pH值显着（p <0.05）在排除位点比在过度上釉的位点要高。在过度放牧的地点，电导率明显高于在排斥地点。这些结果表明，牲畜排斥在退化的牧场生态系统的多样性，覆盖率和土壤特性等植被参数中起着重要作用。此外，在阿尔沙（Arshagh）牧场禁止放牧可能是恢复此类牧场的一种有前途的管理选择。