The Relationship Between Provision And Demand Of Ecosystem Services And Its’ Spatial Variation In Wuhan

Natural ecosystems such as forests and wetlands play an important and diverse role in ecosystem services,serving as the foundation for the survival and development of human society.However,climate change and the continuous increase in human activities are changing the structure and function of various ecosystems,leading to varying degrees of threat or degradation of global ecosystem services.At the same time,the process of urbanization is rapidly changing the population distribution in cities and surrounding areas,leading to changes in the demand for ecosystem services.The combined effects of the two have exacerbated the imbalance and variability in the supply and demand relationship of ecosystem services.In this context,understanding the variability and complexity of the supply transmission consumption process of ecosystem services has become one of the most critical scientific issues facing regional sustainable development.Especially in rapidly urbanizing areas,the uneven land use coverage pattern and its changes further exacerbate the complexity of the supply-demand relationship of ecosystem services,which still lacks in-depth understanding.In order to reveal the spatial heterogeneity of the supply and demand relationship of Urban ecosystem at multiple spatial scales,this study takes Wuhan as the research object,evaluates the supply and demand of key ecosystem services in Wuhan,and analyzes the spatial pattern and matching characteristics of the supply and demand relationship of ecosystem services;The spatial heterogeneity of the supply and demand relationship of Urban ecosystem at multiple spatial scales is revealed by selecting a variety of evaluation unit scales;Evaluate the level of urbanization based on socio-economic indicators and analyze the spatial interaction relationship between urbanization level and the matching characteristics of ecosystem service supply and demand.The research results can provide a basis for the scientific planning of urban ecological function zoning and urban landscape pattern.The main research findings are as follows:(1)There is spatial heterogeneity in the supply of ecosystem services in Wuhan.The supply of material products presents a distribution pattern of four weeks high and middle low,with a range of 0～10010.95kg·ha-1yr-1.The water resource supply range is 5165.83～19576.40m3 ha-1 yr-1,with a relatively high supply capacity in the central and southeastern regions.Water quality purification and carbon sequestration exhibit a similar distribution pattern,with an overall spatial distribution pattern of high in the north and south,and low in the middle,respectively with values ranging of 0～8.89kg·ha-1yr-1 and 0～4698.92kg·ha-1yr-1.Except for the Mulan Mountain area,the soil conservation supply in other areas is relatively low,with a range of 0～382.10t·ha1yr-1.In comparison,the distribution of recreational services is relatively uniform throughout the entire area of Wuhan,with a range of 0～1088.89 people·ha-1.(2)The spatial distribution of ecosystem service demand in Wuhan is uneven.The supply of material products,carbon sequestration,water resource supply,and water quality purification demand all show a distribution pattern of high in the middle and low in surrounding areas,respectively with ranges of 0.09～129224kg·ha-1y-1,223.19～165449 m3～ha-1yr-1,0.14～1521.32kg·ha-1yr-1,1.58～2.33×106 kg·ha-1yr-1.The demand for soil conservation is relatively low across the entire region,ranging from 0 to 64.37 t·ha-1yr-1.The demand for recreation in the central urban area is relatively high,but the overall distribution is relatively uniform,with a demand range of 0～1088.89 people·ha-1.(3)The spatial heterogeneity of the supply and demand relationship of ecosystem services in Wuhan is obvious,and the mismatch between supply and demand in the central city is more prominent than that in the far city.The central city as a whole is in a state of supply deficit.Carbon sequestration services and water quality purification services are generally in a relatively balanced state of supply and demand in remote urban areas,while material product supply,water resource supply,and soil conservation are in surplus.The supply and demand ratio range of various services within the city is:grain production(-1.95～0.04),aquatic product supply(1.072～0.927),water resource supply(-1.651～0.204),water quality purification(1.988～0.011),carbon sequestration(-1.996～0.003),soil conservation(-0.018～1.678),and recreation(-0.011～1.901).(4)Key ecosystem service relationships have scale complexity.The supplydemand ratio of ecosystem services is sensitive to changes in the evaluation unit scale,and water quality purification services are within 500m × 500m grid scale,there is a relatively low spatial discrete distribution pattern,but as the scale expands,the water quality purification services exhibit a spatial aggregation distribution pattern.The smaller the grid evaluation unit scale,the more refined the spatial distribution characteristics of other services.However,as the evaluation scale unit expands,the spatial agglomeration effect decreases,and different services have different sensitivities to changes in scale units.(5)The relationship between the supply and demand of ecosystem services and the level of urbanization is complex.The supply-demand relationship of ecosystem services in areas with higher levels of urbanization is more affected by demand,with all other services showing a strong supply deficit except for soil conservation services.The supply and demand relationship of ecosystem services in low urbanization areas is more determined by the joint supply and demand.And the degree of negative correlation between different service supply and demand relationships and urbanization space varies,with the order of magnitude being:water resource supply(0.581),carbon sequestration(-0.507),water quality purification(-0.477),material product supply(-0.476),soil conservation(-0.137),and recreation(-0.111).This research reveals that the urbanization gradient in Wuhan has a prominent impact on the supply and demand relationship of ecosystem services.The supply and demand relationship of ecosystem services has obvious spatial differentiation characteristics,and presents differentiated spatial distribution patterns at different spatial scales.In the process of protecting and restoring ecological resources such as forests and wetlands,it is necessary to comprehensively consider key ecological construction projects,clarify the composition of regional demand structure and natural resource supply capacity,select appropriate scale units for ecological function zoning,and implement differentiated management strategies.