Ecosystem Services Changes And Restoration Strategies Of Grassland In Western Jilin Province

Grassland degradation is serious in western Jilin Province,salinization is one of the main limiting factors of grassland productivity in this area.Therefore,effective ecological restoration of degraded grassland is an urgent problem to be solved,which will help to enhance the stability and ecological security of grassland ecosystem in western Jilin Province.Based on the four periods of land-use and cover data from 1990 to 2018,this paper analyzes the spatiotemporal features of grassland.Four ecosystem services,including carbon storage,soil conservation,water supply,and habitat quality,were quantitatively evaluated by In VEST model.Based on these four services,the spatiotemporal variation of grassland ecosystem services was analyzed.Spearman correlation analysis was used to determine the relationships among the four ecosystem services,and the hot spots of each ecosystem service were identified.According to the above-mentioned research,a suitable,convenient,and effective grassland ecological restoration strategy was explored.The results suggest:1.From 1990-2018,the overall grassland area presented a tendency of decrease,with the most obvious reduction in high-coverage and medium-coverage grassland.The external factors were mainly the artificial reclamation of grassland into farmland and the degradation of grassland into saline-alkali land.The internal factor was the degradation of grassland coverage.2.During 1990 and 2018,the total carbon storage of grassland in the study area decreased significantly,in which the high-coverage grassland decreased by 20.4841 million Mg(Mg is megagram,1Mg = 1t),the medium-coverage grassland decreased by2.7714 million Mg,and the low-coverage grassland increased slightly to 3002 million Mg.Meanwhile,the total amount of soil conservation showed a downward trend,with the descending order of high coverage grassland > unutilized land > water area >salinized land > medium-coverage grassland > cultivated land > urban and rural construction land > forest land,and the average amount of soil conservation was basically consistent with it.From the perspective of water supply,high-coverage grassland > medium-coverage grassland > low-coverage grassland,but from the perspective of average water supply,low-coverage grassland > high-coverage grassland >medium-coverage grassland,indicating that the function of water supply is directly related to vegetation coverage and area.In the habitat quality assessment of distinct habitats,the average habitat quality index of grassland was the highest(0.98),and that of salinized land was the lowest(0.20).3.During 1990 and 2018,a synergistic relationship exists among soil conservation services,carbon storage and habitat quality;trade-off relationship always exists between water supply and other services.We identified and divided the types of grassland service hotspots.High-coverage grassland and medium-coverage grassland were stable in four types(habitat quality-carbon storage-type,habitat quality-water supply-carbon storage-type,habitat quality-carbon storage-soil conservation-type and a type distributed in four types of service hotspots),while low-coverage grassland was mainly in two types(habitat quality-type and habitat quality-water supply-type).Habitat quality-soil conservation type was added in 2010 and 2018.4.With the support of government policy,the ecological restoration of grassland with different coverage is carried out by means of technology,intergrating the distribution characteristics of the hot spots of grassland ecological service in Western Jilin Province.The restoration strategy of policy + technology + industry is proposed to form a sustainable benign restoration system,At the same time,the relevant government departments need to formulate a perfect system of laws and regulations,strengthen the law enforcement management,and guide the whole society to promote the consciousness of grassland protection.