| Since the 80s of the 20th century,the problem of grassland degradation in China has become increasingly serious,due to the heavy use of grassland,light protection,heavy demand,light input,overload and overgrazing and the impact of climate change,90% of China’s grassland has been degraded to varying degrees.The grassland ecology showed a trend of "improvement in points,degradation on the surface,local improvement and overall deterioration".Based on the current situation,the state issued a grassland ecological protection subsidy and incentive policy in 2011 to protect ecological security and promote herdsmen’s income,in order to seek a balance between economic benefits and ecological benefits.This policy is mainly based on grazing ban subsidies and grass-livestock balance incentives,and the governance idea is to provide ecological incentives and subsidies to herders so that herders can reduce the number of livestock,so as to reduce the overload and overgrazing of pastoral areas and restore the dynamic balance between grassland and livestock.It can be seen that exploring the mechanism of the grassland ecological reward policy is very important for comprehensively and objectively evaluating the implementation effect of the policy and the next step of grassland ecological protection and governance.The study first used ArcGIS software to measure the ecological effects of grasslands in Inner Mongolia and further analyzed their spatiotemporal evolution patterns.Secondly,taking the grassland ecological reward policy as a natural experiment,a "grassland ecological reward policy-livestock production-ecological effects" analysis framework was constructed.Using 20-year panel data for county-level in Inner Mongolia and building a difference-in-differences(DID)model to evaluate and test the ecological effects of the grassland ecological reward policy.Furthermore,a mediating effect model was used to analyze the mechanism of the policy.Finally,heterogeneity of the ecological effects of the grassland ecological reward policy was analyzed from the perspective of regional and vegetation endowment differences.The study draws the following conclusions: First,there are differences in the spatiotemporal distribution of grassland ecological value,but it shows an overall improving trend.Second,the grassland ecological reward policy has a significant positive effect on grass production,water conservation,and carbon fixation ecological function in Inner Mongolia grassland.Third,the scale of livestock production has a mediating effect on the ecological effects of the grassland ecological reward policy,and the indirect negative effect of livestock scale on grass production ecological effects was observed.Fourth,there are significant differences in the ecological effects of the policy in the eastern,central,and western regions,as well as in regions with good or poor vegetation endowment.Based on these findings,the study proposes the following recommendations: First,strengthen the supervision and punishment of illegal grazing and other behaviors.Second,control the scale of livestock breeding,optimize livestock breeding technology,increase the incentive strength and methods for enclosed breeding methods,and increase the quantity and quality of artificial grassland construction.Third,increase the support for enclosed breeding models,promote the further expansion of enclosed breeding scale and supporting facility construction.Fourth,strengthen the cultivation and promotion of dominant grass resources to further enhance the effectiveness of water and soil conservation and windbreak and sand fixation ecological effects.Fourth,according to the grassland vegetation endowment and animal husbandry production in different regions,we should adapt measures to local conditions and highlight the heterogeneity and focus of policies. |
