The Construction Of Ecological Security Pattern In Jiangsu Province Oriented By Connectivity Protection

With the rapid urbanization,frequent human activities and high-intensity land development and utilization are constantly changing the earth surface form.Habitat patches gradually tend to "island",and the ecological space will continue to be fragmented,which has caused problems for the migration of organisms.Biodiversity is threatened,the sustainability of regional development is affected,and the protection of the connectivity of the ecological space is urgent.Since the 18th National Congress of the CPC,the Party Central Committee has attached great importance to the construction of ecological civilization and environmental protection.The report of the 19th National Congress once again emphasized "building ecological corridors and biodiversity protection networks".How to achieve connectivity protection and build an ecological security pattern has become a major proposition in my country's ecological protection work.Jiangsu Province has abundant resources,developed economy,rapid urbanization,and significant differences in the level of regional economic development and ecological protection,which is typical and exemplary.This study takes Jiangsu Province as the research area and aims to realize the provincial ecological security pattern guided by the protection of ecological spatial connectivity.First,the study uses the ecological connectivity evaluation model based on Morphological Spatial Pattern Analysis(MSPA)and Minimum Cumulative Resistance(MCR)to analyze the changes in ecological connectivity at the provincial scale,and simulates the ecological network structure,connectivity and changes of Jiangsu Province.Secondly,the thesis conducts a refined research on connectivity changes in typical areas,and uses Geographically Weighted Regression(GWR)to analyze its spatial response relationship with each influencing factor,and derives the spatial differentiation of the degree of each influencing factor.Finally,combined with the status of ecological protection,the ecological space of Jiangsu Province is simulated and optimized,and a connected protection-oriented ecological security pattern is constructed.The main conclusions are as follows:(1)The study puts forward an ecological connectivity evaluation model that integrates connectivity status and connectivity quality.It is found that the connectivity of the ecological network in Jiangsu Province continues to decline,the ecological network in the north is seriously damaged,and the network relay point in the south is brokenThe study used the MSPA method combined with the area threshold method to identify the ecological source node,constructed the ecological resistance surface corrected by night light data,used the MCR model to simulate the ecological spatial structure of Jiangsu Province,and used the multi-factor comprehensive evaluation method to evaluate the ecological quality.Finally,this paper substitutes the ecological quality and corridor resistance into the Integral Index of Connectivity and Probability of Connectivity to evaluate the connectivity of the ecological space in Jiangsu Province,and constructs an ecological connectivity evaluation model with strong spatial orientation.The study found that from 2000 to 2018,13 ecological nodes in Jiangsu Province were broken and 5 were added.The ecological quality has generally declined,ecological corridors have generally been closed,and the connectivity of ecological spaces has continued to decline.Among them,the northern ecological network is seriously damaged.The fragmentation of important nodes such as the Maling Mountain Scenic Area in Xinyi City and the Dayan Mountain in the north of Danyang City has a greater impact on connectivity.(2)The study verifies the applicability of the ecological connectivity evaluation model on a detailed scale.Combined with the GWR model,it is found that the adjustment of the planting and breeding structure in the direction of urban expansion and the continuous development of industrial parks have the most significant impact on the connectivity of the ecological spaceThis study uses the ecological connectivity evaluation model proposed in the previous article to explore typical areas and verifies the applicability of the model at a fine scale.Finally,exploratory regression is used to determine the six best explanatory variables of housing construction,land consolidation,agricultural adjustment,ecological construction,economic development,and population density.Then this study uses the GWR model to analyze the spatial differentiation of the impact of different variables on ecological connectivity.The results show that the connectivity of the land ecological space in the typical area from 2015 to 2018 is slightly improved,and the three important nodes,including the Jinji Lake Scenic Area,are of great significance to the north and south ecological spaces in the main urban area of Suzhou.The connectivity of the ecological space is affected by a variety of activities.Among them,the adjustment of the planting and breeding structure in the direction of urban expansion,the continuous development of industrial parks in the process of economic development,and the expansion of emerging towns have a significantly higher impact on the connectivity of the ecological space than other regions.The consolidation of residential areas in the suburbs and the ecological construction within the cities and towns have significantly improved ecological connectivity.(3)The research puts forward a new ecological node location model based on improved approximate search method.Combined with measures such as source restoration,stepping stone construction,and breakpoint restoration,the establishment of an ecological security pattern has been achievedBased on the structural importance index and ecological quality index,the study identified 7 ecological sources that are recommended for restoration.Then,based on graph theory,this paper proposes a new ecological node location model with improved approximate search method,which solves the problem of strong subjectivity in ecological construction in the past.The results show that the addition of 9 ecological nodes,including the Tangshan Scenic Area in Jiangning District,Nanjing City,will maximize the efficiency of ecological connectivity.In addition,the study established53 ecological "stepping stones" for high-resistance corridors,and suggested repairing252 ecological "breaking points" caused by high-grade road networks.And 25 corridor maintenance areas and 11 corridor dredging areas were identified based on the circuit theory and barrier restoration method.Through the above measures,an ecological security pattern with unobstructed ecological communication and complete network structure has been constructed.