Ecological network resilience evaluation and ecological strategic space identification based on complex network theory: A case study of Nanjing city

Constructing a resilient ecological network (EN) and identifying critical strategic nodes and corridors within the EN, stands as a pivotal approach toward achieving a harmonious equilibrium between regional development and ecological conservation. It is imperative to expand the perspective to encompass the holistic resilience of the EN, thus identifying and safeguarding ecologically strategic nodes and corridors that play pivotal roles throughout the entire network. Therefore, this study takes Nanjing City as a case study and establishes a comprehensive EN resilience assessment framework based on resilience theory and complex network theory, grounded in a foundation of multidimensional indicators. Building upon this, the research develops the ‘regional network simulation - ecological spatial analysis - strategic spatial identification’ investigative framework. The results show that a core EN structure centered around green spaces, rivers, lakes, and similar features has taken shape, encompassing a total of 39 ecological nodes and 69 ecological corridors. Examining from six perspectives, connectivity, integration, complexity, centrality, efficiency, and substitutability, and their integrated assessment, this study analyzed the impact of single and sequential failures in different EN component spaces on the overall resilience of the EN. The study aimed to identify the component space that significantly contributes to the network's resilience. As a result, the strategic space of the EN was divided into three levels. The ecological source areas 1, 2, 7, and 34, along with ecological corridors 1–34, 1–4, 4–11, 19–34, 18–19, and 27–39, emerge as the primary strategic spaces within the study region. Previous research primarily emphasized the individual characteristics of ecological spaces. However, this study adopts a systemic perspective rooted in resilience theory and complex network theory to meticulously explore the pivotal impact of specific ecological spaces on the overall resilience of the ecological system network. Moreover, it amalgamates considerations of both the significance and scale of ecological spaces, conducting a comprehensive assessment of their combined influence on the overall EN resilience. This approach not only aids in identifying and preserving strategic ecological nodes and corridors but also contributes to evaluating, planning, and restoring regional EN resilience. This progression plays a crucial role in establishing an equilibrium between regional advancement and ecological conservation.