The Response Of Ecosystem Services To Changing Landscape Patterns On The Qinghai-tibet Plateau

The alterations in the structure and functioning of ecosystems arise from the interplay of both natural and human factors.One of the significant ecological issues faced by the Qinghai-Tibet Plateau is the degradation of its landscape ecosystem structure and function due to human activities and global changes.The Qinghai-Tibet Plateau,renowned as the“roof of the world”and the“third pole of the earth”is an ecologically significant area in China.It harbors abundant natural resources and serves vital functions such as carbon fixation,water yield,soil conservation,sandstorm prevention,and global biodiversity conservation.The eastern Qinghai Province,situated in the northeastern part of the Qinghai-Tibet Plateau,acts as a pivotal barrier area in upholding ecological security for the entire plateau.However,in recent years,human activities have escalated,instigating continual modifications to the landscape pattern within the region and impacting the provisioning of ecosystem services.The entire ecosystem of the Qinghai-Tibet Plateau is confronted with an array of ecological issues,including land degradation,biodiversity loss,and heightened soil erosion.In light of these circumstances,exploring the response of ecosystem services to changes in landscape patterns can furnish a scientific foundation and theoretical underpinning for enhancing the ecological environment of the Qinghai-Tibet Plateau.Moreover,such studies can aid in mitigating prominent conflicts between human activities and land use,optimizing landscape management strategies,and establishing sustainable models for ecological governance.The study employed multiple sources of data,including meteorology,soil,vegetation,topography,socio-economic,and land use data.By utilizing the box diagram and landscape index method,the study quantitatively analyzed the spatiotemporal changes in the landscape pattern of the study area from 2000 to 2018.Furthermore,ecological models such as CASA,In VEST,RUSLE,and RWEQ were used to quantify five services,namely carbon fixation,water yield,soil conservation,sandstorm prevention,and habitat quality,from 2000 to 2018.The study explored the spatiotemporal change characteristics quantitatively and spatially mapped the interaction between the services based on correlation analysis and self-organizing map.Finally,this study employs various methods,including local spatial autocorrelation,natural breakpoints,redundancy analysis,and overlay analysis,to explore the response of ecosystem services to changes in landscape patterns.These methods allow for the examination of spatial correlation,the degree of service response to landscape pattern changes,changes in the spatial combination of service bundles and landscape patterns,as well as the interaction between services and natural and human factors.The primary conclusions are as follows:（1）The spatial distribution of land use types in the eastern Qinghai Province exhibits significant variation,predominantly comprising of forested land,grasslands,and unused land,collectively accounting for approximately 87%of the study area.The area of grassland has experienced the highest increase,reaching 2754km²;while cropland and built-up land have remained in a state of expansion,increasing by 251km²and 173km²,respectively.The area of water bodies has witnessed a minor increase of 203km2.On the other hand,unused land has decreased the most,by an area of approximately 3219km²,while forest land has continuously decreased at a small proportion（0.14%）.Approximately 36,225km²of land use was converted between 2000 and 2018,with grassland being the land type with the highest area transferred in and out.（2）The overall landscape aggregation and connectivity in the study area has increased,while landscape fragmentation,complexity,and diversity have decreased.AREA＿MN,AI,and CONTAG increased from 1474.63,69.80,and 34.62 in 2000 to 1656.73,72.33,and 37.16in 2018,respectively.Meanwhile,the rest of the indices indicated a declining trend.In terms of each landscape type,AREA＿MN,AI,and COHESION have been on an increasing trend,while ED,PD,and SHAPE＿AM have experienced a declining trend,indicating an increase in aggregation and connectivity within each landscape type in the study area,but the shape of the landscape is becoming more complex.（3）From 2000 to 2018,with the exception of sandstorm prevention,all other services increased at rates of 7.24g C·m^-2·a^-1,12.19mm·a^-1,6.64t·hm^-2·a^-1,and 0.01a^-1.The spatial distribution of the five services demonstrated obvious heterogeneity.carbon sequestration was high in the north and low in the middle,with high-value areas extending from the south to the middle.High-value areas of water yield were mostly distributed in high-altitude regions,decreasing from north to south in the middle,while the increase in the central south was significantly higher than that in the north.The distribution pattern of soil conservation was low in the middle and high around,and the high-value area extended from southwest to northeast.The distribution pattern of sandstorm prevention was high in the south and low in the north,and the overall spatial change rate increased from the southwest to the northeast.The habitat quality increase area was mainly located in the southwest,while the decrease area was mainly located in Hehuang Valley.（4）Between 2000 and 2018,there were synergistic relationships among carbon sequestration,water yield,and soil conservation.There was a synergy between carbon sequestration and soil conservation,as well as between carbon sequestration and habitat quality.However,trade-offs existed between water yield and habitat quality,and between sandstorm prevention and all other four services.Correlation coefficients among these services showed a weakening of trade-offs and synergies between the services,except for the synergies between carbon sequestration and habitat quality,which increased with inter-annual variation.Three ecosystem service bundles were identified:the human activity bundle,the habitat conservation bundle,and the integrated provisioning bundle.The human activity bundle covered less than 20%of the total study area and was scattered throughout the study area,with the most frequent human activities and a certain level of supply of carbon and water yield services.The habitat conservation bundle had high habitat quality but a low level of supply of other services.The integrated supply bundle covered more than 50%of the study area and provided a large number of ecosystem services.（5）Ecosystem services exhibit complex response relationships to landscape pattern changes.When considering correlations,with the exception of the feeble correlation between wind and sand fixation services and PD,ED,and AI,the remaining services exhibit a robust correlation with the AREA＿MN,AI,and CONTAG.From the standpoint of spatial correlation characteristics,the considerable heterogeneity in the distribution of landscape patterns within the study area can result in heterogeneity in the spatial distribution of various ecosystem services.Regarding the response of different ecosystem services to the landscape index,there is a discernible trend in the median of each service as the values of each landscape index increase.（6）From 2000-2018,the variation in the spatial combination of’bundle-landscape’suggests that the same landscape may provide more than one ecosystem service bundle,and that the ecosystem service bundles provided by a particular landscape may also be unique.The impact of natural factors on ecosystem services was stronger than that of human activities in the study area as a whole,with vegetation cover,meteorological conditions,soil texture,and landscape configuration being the main factors.However,the impact of human activities such as socio-economic and landscape configuration on ecosystem services gradually increased.In terms of ecosystem service bundles,human activities had the strongest influence on ESB1,while natural factors dominated in ESB2 and ESB3.