Assessment Of Five Main Ecosystem Services In Baishan City And Analysis Of Their Driving Factors

Over the past half century,with the rapid development of social economy and the acceleration of industrialization and urbanization,disorderly and irrational land use has caused serious damage to the regional ecological environment,especially in developing countries and resource-based cities.This paper selects 1995,2000,2005,2010,2015,and2020 as the research periods,and takes Baishan City,a typical resource-based city in China,as the research area.The In VEST model is mainly used to quantitatively evaluate regional water production,carbon storage,soil conservation,habitat quality,and net primary productivity(NPP),clarify their spatiotemporal differences,and explore their trade-off/synergy relationships,scale effects,and driving factors,Finally,identify regional ecosystem service clusters and partition their functions in order to provide scientific basis for regional ecological governance.The main results are as follows:(1)The land use structure of Baishan City is relatively simple,with insignificant overall temporal changes,and the expansion of construction land is the main trend.Forest land is the main land type,accounting for about 90% of the total area of the study area;Cultivated land is the second terrestrial type,and is frequently and violently transformed from forest land;The continuous expansion of construction land has led to a trend of fragmentation and heterogeneity of forest and grass space.(2)There are significant differences in the spatiotemporal distribution and evolution of the five ecosystem service functions in Baishan City.In the past 25 years,the spatiotemporal changes in water production and soil conservation functions in Baishan City have been relatively obvious,with both total fluctuations and decreases.In terms of spatial distribution,the water production function is significantly affected by climate factors and the high and low values are concentrated.The function is highly consistent with the terrain distribution,and the spatiotemporal changes in carbon storage,habitat quality,and net primary productivity are relatively similar.(3)The services of various ecosystems in Baishan City exhibit different trade-off synergies at different scales.Only habitat quality and carbon storage services exhibit strong synergy at the global and county scales,while multiple sets of relationships exhibit continuous trade-offs or synergy at the global scale and have strong correlation,while in the county scale,the opposite or weak correlation occurs.(4)Human factors are the main factors affecting the ecosystem service functions of Baishan City.Preliminary analysis through maximum likelihood regression shows that there is a mediating effect between population number(POP)and the proportion of construction land,and POP directly or indirectly affects the change of service functions by affecting the expansion of construction land.Using the optimal geographic detector for further analysis,six natural environment factor factors such as slope(SLOP)and vegetation cover(NDVI)and four human activity representative factors such as human footprint index(HFI)and night light index(NTL)were selected to analyze the driving effects of each factor on each service function,and it was found that POP and NDVI had strong explanatory power on carbon storage,habitat quality and net primary productivity services,revealing the reasons for the high similarity of the spatiotemporal changes of the three.The ranking of strong explanatory factors(HFI,POP,NDVI)for carbon storage and habitat quality services was basically consistent,revealing the intrinsic relationship between the two scales showing strong synergy..(5)According to the spatial distribution characteristics of ecosystem service clusters,Baishan City can be divided into four functional areas: ecological protection area,ecological transition area,water and soil conservation area,and human activity area,with an area of8235 km2,4936 km2,2574 km2,and 1384 km2,respectively.Ecological reserves are dominated by carbon storage and habitat quality services,and are located in woodlands with low human activity and moderate altitude;The ecological transition zone is dominated by water production and net primary productivity services,mainly distributed in high altitude mountains;The water and soil conservation area is dominated by primary net productivity services,with a balanced proportion of other functions.The soil conservation function accounts for the highest proportion among clusters,mainly distributed in the southern gentle zone of the study area;Human activity areas are dominated by water production and primary net productivity services,with the main land types being cultivated land and construction land.(6)According to the spatial distribution of high and low values of ecosystem services in the study area,it can be divided into extremely important areas for ecosystem protection,various service core areas,key ecological protection improvement areas,and key functional improvement areas.Corresponding systems and policies should be formulated based on actual conditions around different regions to strengthen regional ecological protection.For key protected areas with high value clusters,it is necessary to strictly delineate ecological red lines,establish long-term mechanisms,and firmly give priority to ecological protection;For key upgrading areas with low value agglomeration,it is necessary to distinguish between different situations such as towns and cultivated land,implement policies by category,enhance the forward-looking nature of policy formulation,and organically integrate ecological protection theories.In terms of specific functional restoration and upgrading,the policy of giving priority to protection and giving priority to natural recovery should be adhered to;In terms of establishing the overall mechanism structure,it is necessary to comprehensively use various means such as legal,administrative,economic,ideological education,and explore the establishment of a "ecological assessment ecological assessment ecological compensation" mechanism between counties to ensure the sustainable improvement of the regional ecological environment.