放牧管理模式对高寒草甸鼢鼠鼠丘群落演替的影响

高寒草甸放牧利用下高原鼢鼠(Eospalax baileyi)等危害的发生是草地管理的关键难题,分析放牧管理模式对鼢鼠鼠丘植被群落演替的影响能为草地管理提供重要依据。研究选择划区轮牧(RG)、生长季休牧(GSG)、连续放牧(CG)和禁牧(PG)4种放牧管理模式,以及各模式下不同年限鼠丘(一年(ZM1)、两年(ZM2)、三年(ZM3)和多年鼠丘(ZMM))与对照(CM)草地。分析不同放牧管理模式对鼠丘植被群落特征和生物量等的影响,结果发现:PG和GSG下所有年限鼠丘的植被高度、地上生物量均高于RG和CG;RG和GSG下ZM1和ZM2物种Shannon-wiener指数均高于对照样地物种Shannon-wiener指数。主成分分析表明:RG下地上生物量和物种丰富度指数是影响鼠丘植被群落演替的重要因子,PG下地上生物量、盖度、Shannon-wiener指数和均匀度指数是鼠丘植被群落演替的重要因子,CG下物种丰富度和重要值是影响鼠丘植被群落演替的重要指标,GSG下Shannon-wiener指数、盖度和高度是影响鼠丘植被群落演替的重要指标。可见,不同放牧制度对鼠丘植被群落演替的影响不同,禁牧和生长季休牧管理模式能够较好地恢复鼠丘植被群落演替。

Effects of different grazing strategies on zokor mounds plant community succession in alpine meadow

The rodent damage by plateau zokor in the process of alpine meadow grazing is a key problem in its utilization and management. Grazing is one of the most important ways of using grassland. The grazing system is used as a utilization system in grazing management. It regulates the use of livestock in the time and space of grazing land, and adjusts the grazing intensity and grazing frequency to balance vegetation grow and livestock. A reasonable grazing system can improve the diversity of grassland plant communities and the stability of grassland ecosystems, and is of great significance for promoting the healthy development and sustainable use of grassland. Plateau zokor is one of the dominant mounds of alpine grassland on the Qinghai-Tibet Plateau. It mainly feeds 3-20 cm of plant roots and stems below the surface. Excavation and hill-building activities of plateau zokor is one of the important driving factors for grassland degradation. The zokor mound is one of the important ways to affect grassland. It is mainly reflected in the coverage of grassland original vegetation, the reduction of species diversity in the community and affecting the productivity of grassland vegetation and the composition of aboveground vegetation. Vegetation community succession of zokor mounds under different grazing management models can provide important basis for grassland management. To analyze the effects of different grazing management models on the vegetation community characteristics and biomass of the rodent mound, four different grazing management models were selected in this study: rotational grazing (RG), growing season grazing (GSG), continuous grazing (CG) and prohibition grazing (PG), with different ages of zokor mounds in each model including one-year (ZM1), two-year (ZM2), three-year (ZM3), multi-year (ZMM) zokor mounds, and control meadow (CM). The results showed that under PG and GSG, the vegetation height and aboveground biomass of zokor mounds in all ages were higher than those of RG and CG. The Shannon-Werner index of ZM1 and ZM2 species under RG and GSG was higher than the species of control meadow. The results of principal component analysis (PCA) showed that aboveground biomass and species richness under RG, while aboveground biomass, coverage, Shannon-Wiener diversity index, and uniformity under PG were important factors of vegetation community succession on zokor mounds. Species richness and important value under CG and Shannon-Wiener diversity index, coverage and height under GSG were critical indicators affecting the vegetation community succession of zokor mounds. In conclusion, different grazing modes have different effects on vegetation community succession of zokor mounds. It can be effectively restored under PG and GSG.