| Harding’s "tragedy of the commons" theory has been cited as the theoretical basis for grassland privatization worldwide,although there are many research and practical programs on grassland degradation,it is undeniable that the problem of grassland degradation is still widespread.Moreover,a large number of ecological studies have proved that restricting the movement of herds through fences will have many negative impacts on ecology,production,and livelihoods.However,grassland animal husbandry management often follows different models,these important grassland management practices provide a valuable reference for the construction of sustainable grassland animal husbandry management models in the Qinghai-Tibet Plateau region.In order to explore the impact of different grassland animal husbandry management models on grassland ecosystem and which grassland animal husbandry management model is more conducive to the sustainable development of grassland animal husbandry,we use the ordinary pastoral area in the eastern part of the Qinghai-Tibet Plateau as the research area.And take the direct participants in the management and utilization of the Qinghai-Tibet Plateau grassland-herders,as the research objects.First,we use 30-year time series of high-resolution satellite images to study the changes in the normalized vegetation index(NDVI)of grassland vegetation before and after the implementation of the household contract management system(HCMS).And establish a GLMM model based on long-term series of NDVI data and field survey data to explore the response of grassland vegetation NDVI to different grassland animal husbandry management models.Secondly,we use field survey data based on the perception and evaluation of herders to deeply explore the impact of different grassland animal husbandry management models on the grassland ecosystem,on this basis,the herdsmen’s perception and evaluation information of grassland ecosystem changes are matched and verified with the grassland vegetation NDVI change information monitored by remote sensing,in order to jointly explain the actual impact of the grassland animal husbandry management model on the grassland ecology and whether the herders have an accurate cognition of the advantages and disadvantages of the grassland animal husbandry management model.We use the field survey data to establish a Logistic regression model to systematically analyze the herdsmen’s behavioral choices(cooperative grazing behavior)and influencing factors on grassland animal husbandry management models.And combines the current situation of the herdsmen’s grassland animal husbandry management models in the study area to make an in-depth interpretation of the model results.We also use the quantitative and qualitative data collected from field surveys to further analyze and reveal the grassland ecological changes and livelihood risks faced by local herdsmen in the production and life of animal husbandry,by combining empirical cases and framework models to explore the important role played by community organizations of animal husbandry in coping with these difficulties and challenges,and the possibility of reshaping the sustainable management model of grassland animal husbandry in the pastoral areas of the Qinghai-Tibet Plateau.At the end of the thesis,we also actively explore the dilemmas that need to be broken through from the perspective of government departments and herdsman,and put forward relevant suggestions that can effectively protect the grassland ecology and maintain and improve the livelihoods of herdsmen.Through research we got the following results:1)There is no evidence that the grassland household contract management system is improving the current state of grassland degradation in the eastern part of the Qinghai-Tibet Plateau.By linking the Normalized Vegetation Index(NDVI)and grassland animal husbandry management models,it is found that in terms of spatial scale and herd size,the higher the fragmentation degree of grazing and pasture,the lower the NDVI value,and the stronger the degree of grassland degradation.2)The analysis results of herders’ perception and evaluation of grassland ecological status show that herders have a clear understanding of the ecological problems that may be caused during the implementation of the grassland household contract management system.The size of the fence is considered to be the main cause of grassland degradation,that is,the smaller the fenced plot,the more severe the degradation,which is consistent with the conclusion we reached by linking the Normalized Vegetation Index and the grassland animal husbandry management model.3)The Logisitic regression model is used to analyze the behavior choice and influencing factors of grassland husbandry management models of herders.The results show that: family income source items,family social relations,livestock species,herders’ grazing preferences,internal management mechanism,transportation,grassland quality,and the difficulty of moving pastures has a positive and significant impact on the herdsmen’s selection of the grassland animal husbandry management model based on group(cooperative grazing behavior);Income and expenditure items,livestock inventory,grassland heat distribution and distance between winter pasture and summer pasture have a negative and significant impact on the herdsmen’s selection of the grassland animal husbandry management model based on group(cooperative grazing behavior).4)From 1999 to 2015,the total population of the study area has increased by40.88%,and the grassland area has basically remained unchanged due to the implementation of the grassland contracting policy,resulting in a decrease of 26.33%in the grassland area per household,therefore,the overload phenomenon is still serious,and the contradiction between grass and livestock is still prominent.In addition,due to varying degrees of degradation of Maqu grassland in recent decades,the availability of grassland has been significantly reduced,and the balance between herdsmen,livestock,and grassland has long been broken,the degradation of grassland and livestock will continue,and as the population increases,the grassland ecology and the livelihoods of herders are facing greater difficulties.5)As an important practice of grassland animal husbandry management,the research results clearly point out that the grassland animal husbandry management model based on groups(cooperative grazing)and its derived internal management mechanism are effective measures that can restrain the herdsmen’s grazing management behavior produced during the implementation of grassland contracting policy,and also play an important role in the protection of the grassland ecosystem and the maintenance of the herdsmen’s livelihood,as an important breakthrough in the sustainable management of grassland and animal husbandry,to some extent,it has pointed out new models and development directions that may be tried in the future for herders and government departments. |
