Impacts Of Changes In Climate And Landscape Patterns On Ecosystem Services In The Qinghai Lake Basin

Ecosystem services,as one of the important indicators to measure the quality of the regional ecological environment,are the bridge and tie between the natural environment and human society,and are the theoretical basis for ecological protection,ecological function zoning,natural asset accounting and ecological compensation.Changes in climate and land use interfere with the evolution of landscape patterns,causing changes in the supply capacity of ecosystem services,and profoundly affecting human well-being.Understanding the impact mechanism of climate and landscape pattern changes on ecosystem services is the basis for coping with climate change and scientific management of land resources.Therefore,based on meteorological data,land use data,remote sensing data,soil data,and environmental data,this paper selects the Qinghai Lake basin(QLB)in the northeastern part of the Qinghai-Tibet Plateau.the ANUSPLIN interpolation method and the landscape index method are used to analyze the temporal and spatial characteristics of temperature,precipitation and landscape pattern in the Qinghai Lake basin from 2000 to 2018;Using the In VEST model and CASA model to analyze the quality of the ecosystem services(water supply services,soil conservation services,and net primary productivity services)in the Qinghai Lake Basin,as well as trade-offs and synergies;using Person correlation coefficients and bivariate spatial autocorrelation analysis Method,analyzed the impact of temperature,precipitation and landscape index on ecosystem services,identified the main driving factors of ecosystem services,and explored the driving mechanism of ecosystem services in the alpine environment of the Qinghai-Tibet Plateau.Finally,based on the regional differences and key driving factors of ecosystem services,the county-level environmental protection and ecological construction management countermeasures in the QLB are proposed.It provides a reference for the optimization of land resources in the QLB,the improvement of ecosystem service capabilities,and the management and protection of natural resources,and enriches the case studies of ecosystem services in the alpine climate zone of the Qinghai-Tibet Plateau in my country.The results of the study show:(1)From 2000 to 2018,the temperature in the Qinghai Lake basin showed an upward trend,with a growth rate of 0.3°C·10a^-1,and the precipitation showed a significant upward trend,with a growth rate of 73.2mm·10a^-1,and the overall climate in the basin tended to be warm and humid.In the context of global warming,the temperature in the Qinghai Lake basin has changed significantly,which has an important indicator of global climate change;(2)During the study period,the desert has been reduced by 31.43×10⁸m²,and the grassland has increased by30.32×10⁸m².The desert area in the northwestern part of the basin has been reduced and turned into grassland.The regional ecological environment has improved.The main reason is the implementation of large-scale ecological construction projects,as well as natural factors such as the climate in the basin tending to be warm and humid,and vegetation coverage has increased.The same kind of landscape index in different years took 2000-2010 as the transition period.The structure and spatial configuration of the landscape changed significantly in the northwest of the basin,and the landscape pattern in other regions was relatively stable.(3)The multi-year average of water resources supplied in the QLB from 2000 to 2018 was 3.72×10⁹ m²·a^-1.From 2000 to 2012,Water supply increased slowly year by year,and after 2012,it showed an increasing trend of fluctuations;The multi-year average of soil conservation in the QLB from 2000 to 2018was 1.09×10⁹ t·a^-1,and the soil conservation per unit area was 365.91 t·hm^-2·a^-1.The overall soil conservation from 2000 to 2018 was increasing trend of volatility,slower growth rate and violent fluctuations;From 2000 to 2018,the multi-year average of the total amount of NPP was 3.70×10¹² gc·a^-1,and the average per unit area was 148.59gc·m^-2·a^-1.The NPP in the QLB showed a fluctuating upward trend,with a growth rate of 1.69 gc·m^-2·a^-1.The trade-offs and synergy between ecosystem services have obvious scale effects.Water supply and NPP generally show a trade-off relationship,and soil conservation and NPP,soil conservation and water supply are generally synergistic.(4)From the perspective of climatic factors,temperature has a significant negative correlation with water supply and soil conservation,and a significant positive correlation with net primary productivity;Precipitation has a significant positive correlation with water supply and agglomeration characteristics,an insignificant positive correlation with soil conservation,and an insignificant negative correlation with net primary productivity.From the perspective of landscape pattern factors,with the exception of grassland,the correlation between landscape indices of other landscape types and ecosystem services(water resource supply services,soil conservation services,and net primary productivity services)is not significant.In the northwest of the basin,Patch density(PD),Area-weighted Mean Perimeter-Area Ratio(PARA?AM),and Mean Patch Fractal Dimension(FRAC?MN)are negatively correlated with ecosystem services(water supply services,soil conservation services,and NPP services).Largest Patch Index(LPI)is negatively correlated with water supply services,and positively correlated with soil conservation and NPP.(5)In Tianjun County's ecosystem services,water supply is the advantage and net primary productivity is the disadvantage.Attention should be paid to the protection of surface vegetation to prevent the expansion of land desertification.The negative correlation between the supply of water resources and the NPP balance is transformed into a positive synergistic correlation through the protection of vegetation,and the increase in vegetation coverage is transformed;Both Gangcha County and Gonghe County take the NPP supply function as the advantage,and the water supply and soil conservation services are the disadvantages.Appropriate development of grassland resources and tourism service industry activities,reduce soil erosion along the lake,and prevent the expansion of land desertification.The negative correlation between soil conservation services and NPP is transformed into a synergistic positive correlation through the increase of vegetation coverage;Haiyan County has low water resources supply,soil conservation and NPP services.We should attach great importance to vegetation protection and vegetation restoration,strengthen wind and sand fixation,maintain water and soil and enhance soil conservation services along the lake.The negative correlation between soil conservation services and NPP is transformed into a synergistic positive correlation through the increase of vegetation coverage.