Characteristics and optimization strategies of ecosystem service spatial network in Poyang Lake urban agglomeration

Objective Taking Poyang lake urban agglomeration as an example，this study explores the characteristics of the spatial network structure of ecosystem services of urban agglomeration and their optimisation strategies，thus providing references for ecological environmental protection，territorial space governance and high-quality development of urban agglomeration. Method The InVEST model was used to measure the supply of ecosystem services in the study area from 2000 to 2020 and analyzed its spatial and temporal evolution，the spatial autocorrelation and modified gravity models were used to explore the spatial autocorrelation and spatial network structure of the integrated ecosystem services，and targeted optimization strategies were proposed. Result （1）From 2000 to 2020，water yield and soil conservation increased by 5.665% and 16.240%，respectively，while carbon storage and habitat quality decreased by 1.842% and 4.509%，and the integrated services mainly showed a spatial pattern of ‘high in the surroundings，low in the middle and along the river’；（2）Ecosystem services showed significant spatial proximity effects and spatial spillover phenomena，with inter-area linkages tending to decline，inter-area spillover effects appearing to weaken，the contiguity of hotspots and coldspots was obvious，and there was significant fluctuations and expansion in some of the coldspot areas；（3）The structure of the spatial network of ecosystem services had the complex characteristic of multiple interconnections，showing the spatial distribution pattern of ‘one big core and three small cores’ as a whole，and the tendency of the complex network of multiple interconnections gradually evolving into a simple and independent network in time；（4）In terms of the optimization strategy，it is recommended to cultivate and maintain core ecological source areas，reasonably optimize the “three living spaces” pattern，accelerate the establishment of cross regional ecological protection compensation mechanisms，and coordinate the coordinated development between various systems. Conclusion The network connectivity of ecosystem services in the Poyang Lake urban agglomeration is gradually weakening.Promoting the multi connectivity of cities through reasonable means can help establish an ecological compensation mechanism for the urban agglomeration.