Reconsidering the efficiency of grazing exclusion using fences on the Tibetan Plateau

重新认知青藏高原围栏禁牧的作用

Grazing exclusion using fences is a key policy being applied by the Chinese government to rehabilitate degraded grasslands on the Tibetan Plateau(TP)and elsewhere.However,there is a limited understanding of the effects of grazing exclusion on alpine ecosystem functions and services and its impacts on herders’livelihoods.Our meta-analyses and questionnaire-based surveys revealed that grazing exclusion with fences was effective in promoting aboveground vegetation growth for up to four years in degraded alpine meadows and for up to eight years in the alpine steppes of the TP.Longer-term fencing did not bring any ecological and economic benefits.We also found that fencing hindered wildlife movement,increased grazing pressure in unfenced areas,lowered the satisfaction of herders,and rendered substantial financial costs to both regional and national governments.We recommend that traditional free grazing should be encouraged if applicable,short-term fencing(for 4-8 years)should be adopted in severely degraded grasslands,and fencing should be avoided in key wildlife habitat areas,especially the protected large mammal species.

围栏禁牧是中国政府为恢复青藏高原等地退化草地而采取的一项重要政策.然而,关于围栏对高寒草地生态系统功能和服务及其对牧民生计的影响,人们的认识还很有限.本研究荟萃分析和基于问卷的调查显示,围栏禁牧时间长达4年和8年的时间里可以有效地促进高寒草甸以及草原的地上植被生长,更长时间的围栏并没有带来任何生态和经济效益.研究还发现,围栏限制了野生动物的活动范围,增加了非围栏地区的放牧压力,降低了牧民的满意度,且给地区和国家政府带来了巨大的财政成本.因此,建议在适当的情况下,应鼓励传统的游牧方式来利用草地,在严重退化的草地上应采用短期围栏(4~8年),在重要的野生动物栖息地应避免使用围栏,特别是受保护的大型哺乳动物分布的区域.研究结果可为青藏高原草地可持续管理提供一定的参考.