Driving Mechanism And Repair Strategy Of Grassland Ecological Degradation In Altay Region

In order to explore the driving force and change mechanism of grassland ecosystem degradation in temperate zone under the background of global warming,this paper,with the help of regional advantages of remote sensing technology,integrates the basic principles and methods of ecological hydrology,restoration ecology and geography,and combines the data of meteorology,vegetation,social economy,etc.,takes Altay area,which is rich in grassland types,as the research area In this paper,the coverage,grass yield and ecological service value(ESV)were selected as the quantitative indexes to analyze the trend,law and spatial difference of grassland degradation,evaluate the loss of ESV of grassland degradation,clarify the main driving factors and influence intensity of grassland degradation,and put forward the specific measures and guarantee mechanism of ecological restoration of grassland degradation area.It provides a scientific basis for controlling the trend of grassland ecological degradation in Altay.The results show that:(1)From 2000 to 2017,the degree of grassland degradation in Altay region was increasing.In terms of space,more than 50% of the grasslands in the whole area are degraded in varying degrees,the fragmentation degree of grassland landscape continues to increase,and the diversity and evenness continue to decrease;the area of grassland with higher coverage(coverage > 0.6)decreases significantly,and it constantly transfers to the grassland with lower coverage(coverage < 0.4),the grass amount of the grassland decreases,and the mountain areas with higher vegetation coverage in the Altai mountain area and in front of the mountain area The degradation of meadow and temperate grassland is obvious.(2)Using the time integrated normalized difference vegetation index(TI-NDVI)as the equivalent correction coefficient of ESV,the loss of grassland ecosystem service value in Altay region was calculated for the first time by enhancing the heterogeneity expression of ESV spatial distribution.The loss of grassland ESV in Altay region during the 18 years from 2000 to 2017 was 5.10%.(3)In terms of nature,starting from the relationship between the development of grassland and the changes of precipitation and temperature,more than 92% of the grassland distribution areas in Altay region became warm and wet from 2000 to 2017,and a large area of grassland in the arid plain region improved under the improved water supply conditions,while in the relatively cold mountainous region,a large area of grassland degraded under the improved natural conditions.(4)In terms of human factors,the rate of grassland overload in Altay is as high as 52%,and that in spring and autumn is 69%.48.47% of the grassland vegetation changes were dominated by human factors,46.82% by climate factors,and 4.71% by both.At the same time,94.00% of degraded grassland was dominated by human factors,and 93.13% of improved grassland was dominated by climate factors.Thus,for the first time,the relationship between Grassland Change and nature and man-made is clearly distinguished,and the main causes of grassland degradation in Altay area are pointed out,which provides scientific basis for future grassland protection and improvement of grassland conditions.(5)According to the current situation and causes of ecological degradation,combined with the local actual situation,the following specific measures can be taken: A.the appropriate time for grass cutting should be from July 26 to August 9,and the reasonable use of grassland resources is conducive to the restoration of grassland as soon as possible.B.We will carry out engineering measures such as grassland restoration and protection projects,ecological corridor construction,fencing,artificial replanting and control of poisonous weeds and rats and insects.C.Non engineering measures such as the development of animal husbandry industrial park,the planting of feed shrubbery,the reasonable control of grazing intensity and the adjustment of industrial structure were taken.Adhere to the purpose of promoting the sustainable development of social economy and the harmonious development of ecological environment,rely on the ecological compensation policies,projects and measures to promote the development of local agriculture and animal husbandry to the modernization process,promote the ecological compensation and policy reward and punishment mechanism to ensure the smooth implementation of ecological restoration measures,and gradually realize the grassland recovery and sustainable development and utilization in Altay area.