Landscape Change And Ecosystem Service Function Evaluation In Yongshou County

The Loess Plateau is a typical ecologically fragile area.Studying the land-use and ecosystem services changes in this area can provide theoretical support for comprehensively improving the stability of the ecosystem,planning of landscape patterns and rational use of resources.In this study,Yongshou County,a typical hilly and gully area on the Loess Plateau,was selected as the study area,land use data in 1985,1995,2005,2015,and landscape indexes were selected to analyze the landscape pattern changes in county.Besides,the CA-Markov model used to predict the future landscape pattern and discussed the landscape pattern changes under the Business as Usual,the Agriculture Protection Scenario and the Ecological Protection three different scenarios.The InVEST model was used to evaluate the carbon storage,soil conservation,water yield,and habitat quality services in Yongshou County,analyzed the ecosystem services spatio-temporal changes characteristics,and the different landscape types changes on ecosystem services.Correlation analysis and root-mean-square deviation method adopt to evaluate ecosystem services comprehensively.On this basis,K-means method was used to divide the ecological function areas in Yongshou County.The results as follows:(1)The main landscape type in Yongshou County is cropland.Due to the ecological restoration project implemented,from 1985 to 2015,the area of cropland decreased by1746.36 ha(4.13%),the area of grassland increased by 1410.03 ha(4.54%),the area of forestland and shrubland increased by 130.86 ha(1.6%)and 14.04 ha(0.53%),respectively.The area of cropland converted to grassland is the largest,mainly distributed in the northeast and middle of the study area.The overall patch number and patch density of Yongshou County have increased,and the landscape has been severely fragmented,but the clustering of patches is relatively high and the spatial pattern is relatively stable.In addition,the shape of landscape patches tends to be more regular,and the ecosystem is becoming more complex.(2)Under the Business as Usual,the Agriculture Protection Scenario and the Ecological Protection three different scenarios in 2035 and 2055,the area of cropland and construction land will decrease.Among them,the area of cropland will decrease the most under the Business as Usual Scenario,the least decrease under the Agriculture Protection Scenario.Oppositely,the construction land will decrease the most under the Agriculture Protection Scenario,the least decrease under the Business as Usual Scenario.Forestland,shrubland and grassland have increased the most under the Ecological Protection Scenario.The fragmentation degree of the landscape in the three scenarios is reduced,the connectivity between the landscapes are strengthened,and the shape tends to be regular.The aggregation between each type of landscape is strengthened.(3)From 1985 to 2015,Carbon Storage increased by 0.17×10~6t.The total Carbon Storage of cropland was the largest.The average Carbon Storage in the northwest of the study area was the largest,while in the east was smaller.Soil Conservation service decreased by 3,575.52×10~6t.The grassland type had the largest soil conservation.The average Soil Conservation in the northwest of the study area was the largest,while the southern was smaller.Water Yield service has reduced by 235.51×10~6mm.The Water Yield of cropland type is the largest,and the average Water Yield is the largest in the northwest of the study area,while smaller in the east.Habitat Quality services increased.The forest type had the highest Habitat Quality index.The northwest of the study area had the Habitat Quality index,while the east and central area had the lowest.(4)Carbon Storage and Soil Conservation services of Yongshou County are the largest under the Agriculture Protection Scenario,Water Yield service are the largest under the Business as Usual Scenario,and the Habitat Quality service is the largest under the Agriculture Protection Scenario and Ecological Protection Scenarios.(5)Carbon Storage is highly positively correlated with Water Yield.The relative benefits of Water Yield services in high-altitude areas are relatively large,while the relative benefits of Carbon Storage and Habitat Quality services in low-altitude areas are relatively large.The impact of landscape indices on ecosystem services is as high as 80%.Most areas of Yongshou County are in key water conservation areas.High-functional areas are mainly located near forestland,while low-functional areas are mainly located around construction land.(6)Based on the analysis of landscape patterns and ecosystem services in different scenarios,the following suggestions are put forward for the sustainable development of Yongshou County:adhere to the principle of"ecology first,protection first",and further improve the intensification of construction land to build a green and ecological urbanization system;planning the permanent basic farmland protection red line,adjust the unreasonable farmland structure and improve the quality of farmland;Strengthen the management of forest land,scientifically delineate the red line of ecological protection,optimize the structure of forest stands,and rationally adopt measures such as thinning to improve ecological benefits.