The Change And Relationships Of Ecology,Production And Livelihood In Different Pastoral Areas Of The Tibetan Plateau

With the global climate change and the development of human society,the structure,function and management patterns of grassland husbandry in China have undergone great changes,which have had a profound impact on the ecology,production and life of plateau pastoral areas.With the support of national policies and the drive of market economy.In the past 20 years,there have been great changes in the production scale and patterns of alpine grassland husbandry on the Qinghai-Tibetan Plateau,especially the rapid development of joint household and cooperative management on the basis of single household management.What are the effects of these changes on the ecology,production and life of alpine pastoral areas?What is the connection between them?What are the differences between pastoral areas?In order to solve the above questions,this study conducted field investigation on 427grassland husbandry system in four typical alpine pastoral areas of Maqu county in Gansu province,Ruoergi county in Sichuan province,Maqin county in Qinghai province,Naqu county in Tibet,including single-family,joint-family and cooperative management.The livestock species,herd structure,production scale,economic benefits and other grass husbandry were researched.The grassland vegetation and soil samples were collected,the dietary of 446 herdsmen were investigated,639 herdsmen health indicators were measured,116 herdsmen hair samples were collected.17 indicators including the grassland ecology and production parameters total carbon and total nitrogen of herdsman hair,total ¹³C,¹⁵N isotope and amino acid ¹³C,¹⁵N isotope amino acid content were analyzed.A systematic analysis was made from the grassland ecology,grass husbandry production,system carbon emission and nutrition and health of herdsmen.The structural equation model（SEM）,data envelopment analysis（DEA）,life cycle assessment（LCA）,TOPSIS model and multi-objective optimization model were used to study the effects on ecological function,production function and herdsmen’s life in alpine areas,the comprehensive benefits and potentials of three management patterns in different areas.The main findings are as follows.（1）The cooperative management pattern had higher soil organic carbon storage（511±137 Mg/ha）in Maqu country,nitrogen storage（14±2.3 Mg/ha）and relatively higher grassland health index（0.795）than other management patterns.The single-family management in Maqin county and Naqu county had high soil organic carbon storage（332±67.3 Mg/ha,231±24.4 Mg/ha）,total nitrogen storage（27.3±5.5 Mg/ha,19.1±2.2 Mg/ha）,excellent forage and forb biomass,and relatively high grassland health index（0.771,0.758）（P<0.05）.Based on the above ground vegetation and soil related indexes,the order of grassland ecological health index was single-family management（0.782）>joint-family management（0.756）>cooperative management（0.735）.（2）The crude protein yield of cooperative management in Maqu county and Ruoergai county was higher than other management patterns.The crude protein yield of single-family management in Maqin county（323±36 kg/ha DM）and Naqu county（224±37 kg/ha DM）were higher than other management methods.In general,the cooperative management system in the four pastoral areas has high comprehensive efficiency（0.780）,pure technical efficiency（0.869）and scale efficiency（0.890）,while the single-family management system has lower comprehensive efficiency（0.335）,pure technical efficiency（0.434）and scale efficiency（0.734）.At the same time,the cooperative management had high economic benefits（67992±5350 CNY/household）.（3）The total life cycle method（LCA）was used to evaluate the greenhouse gases emission equivalents of different management patterns in four regions.A total of 22greenhouse gases emission sources were selected,among which livestock accounted for the highest proportion of greenhouse gases emissions among all emission types.Compared with single-family(18.02 kg CO_2e/kg live body weight)and joint-family(15.62 kg CO_2e/kg live body weight),the cooperative management(21.43 kg CO_2e/kg live body weight)had higher greenhouse gases emission,which mainly due to higher electricity and fuel consumption.（4）The average consumption of meat,grain and vegetable was 42±3 kg/year,180±5kg/year and 47±2 kg/person/per year,respectively.From Ruoergai county in Sichuan province to Naqu county in Tibet,the herdsmen of animal food intake increased.Herders of Maqin county and Naqu county had a relatively high proportion of overweight.δ¹⁵N isotope content and branched chain amino acids in hair of Naqu county again to verify its diet high in meat intake increased the herdsmen potential health risks.Theδ¹³N isotope content ranged from-22.79 to-21.48‰,indicating that C₃plants were the main grain food of herdsmen in the four study areas.（5）Combining with TOPSIS model,the evaluation index system of the comprehensive effect of grassland management patterns was constructed by selecting 13 indicators.Considering the differences of grassland types,development status,policy background and climate characteristics in different regions of the Qinghai-Tibetan Plateau,the comprehensive benefits were high in joint-family management of Maqu county.The comprehensive benefits were high in cooperative management of Ruoergai county.The high comprehensive benefits were high in single-family management of Naqu county and Maqin county.In conclusion,there are regional differences in grassland health and significant impacts on greenhouse gas emissions.The comprehensive efficiency of grassland husbandry system was positively correlated with the size of grassland area,which indirectly affected the meat intake of herdsmen.The annual household income significantly affects the physical indexes of herdsmen.Therefore,the appropriate adjustment of alpine grassland husbandry management patterns according to regional differences can coordinate the balanced development of ecology,production and life,and contribute to the sustainable development of pastoral areas on the Qinghai-Tibetan Plateau.