A method of linking functional and structural connectivity analysis in urban green infrastructure network construction

Yang Liu,Xi Zheng,Ting-Ting Huang

doi:10.1007/s11252-022-01201-2

Abstract

Accelerated urbanization and population growth lead to the fragmentation of urban green space and loss of biodiversity. There are few studies on the integration of structural and functional connectivity to solve this problem. Our study aims to draw up a methodology to synthesize two methods of connectivity evaluation, accordingly, to construct an urban green infrastructure (UGI) network which is of great significance to maintain the stability of the urban ecosystem. Taking Beijing as a study area, we first used Morphological Spatial Pattern Analysis (MSPA) to identify the source patches, then combined with the graph theory-based landscape metrics to discuss the effect of different diffusion distances on the regional landscape connectivity and classify the importance level of the source patches. Finally, we used both least-cost path (LCP) and circuit theory to construct network and identify pinch areas in corridors for network optimization. The results show that (1) the landscape connectivity of the study area is obviously polarized. Source patches in mountain and hilly areas have good ecological bases and large areas, and the density of corridors is relatively high, which makes a large contribution to the overall landscape connectivity; Source patches in plain areas are severely fragmented, and there are only a small number of potential corridors connecting urban areas and suburban areas. (2) The UGI network is composed of 70 source patches and 148 potential corridors. The diffusion distance that is most beneficial to improve landscape connectivity is 20–25 km. (3) 6 pinch areas that are of great significance for improving the connectivity of the landscape present the coexistence of high migration resistance and large optimization potential, and urgently need to be restored first. This study provides a method to combine the structural and the functional analysis to construct a UGI network and formulate more scientifical protection strategies for planning departments.

Highlights

Urbanization and landscape fragmentation can affect the material flow and energy balance of the urban natural ecosystems, making the system more and more vulnerable to structural changes (Alberti and Marzluff 2004) and becoming one of the main reasons for the loss of biodiversity (Breuste et al 2015)
Took Beijing as the study area, firstly, we extracted source patches and explored the optimal distance threshold that is conducive to the improvement of connectivity based on Morphological Spatial Pattern Analysis (MSPA) and landscape connectivity metrics
According to the current density, the relative importance of source patches was analysed, and the pinch areas affecting corridor connectivity were identified for network optimization

Summary

Introduction

Urbanization and landscape fragmentation can affect the material flow and energy balance of the urban natural ecosystems, making the system more and more vulnerable to structural changes (Alberti and Marzluff 2004) and becoming one of the main reasons for the loss of biodiversity (Breuste et al 2015). MSPA is an image processing method that relies on land use data to quickly and objectively identify seven landscape classes that are important for maintaining connectivity (Riitters et al 2009; Shi and Qin 2018). It has been used in different world countries for GI assessment at national (Wickham et al 2009), regional (Carlier and Moran 2019) and urban scales (Shukla and Jain 2019). As with FRAGSTATS landscape metrics, MSPA is difficult to explain the response of the ecological process to landscape pattern and quantify the relative importance of landscape elements accurately (Wang and Liu 2019).

Objectives

Methods

Results

Discussion

Conclusion