The Effect of Blue-Green Infrastructure on Habitat Connectivity and Biodiversity: A Case Study in the Ōtākaro/Avon River Catchment in Christchurch, New Zealand

Thuy Thi Nguyen,Markus Pahlow,Colin Meurk,Bethanna Jackson,Rubianca Benavidez

doi:10.3390/su13126732

Abstract

The natural capital components in cities (“blue-green infrastructure” BGI) are designed to address long-term sustainability and create multi-benefits for society, culture, business, and ecology. We investigated the added value of BGI through the research question “Can the implementation of blue-green infrastructure lead to an improvement of habitat connectivity and biodiversity in urban environments?” To answer this, the Biological and Environmental Evaluation Tools for Landscape Ecology (BEETLE) within the Land Utilisation and Capability Indicator (LUCI) framework was adopted and applied in Christchurch, New Zealand, for the first time. Three ecologically representative species were selected. The parameterisation was based on ecological theory and expert judgment. By implementation of BGI, the percentages of habitats of interest for kereru and paradise shelduck increased by 3.3% and 2.5%, respectively. This leads to improved habitat connectivity. We suggest several opportunities for regenerating more native patches around the catchment to achieve the recommended minimum 10% target of indigenous cover. However, BGI alone cannot return a full suite of threatened wildlife to the city without predator-fenced breeding sanctuaries and wider pest control across the matrix. The socio-eco-spatial connectivity analysed in this study was formalised in terms of four interacting dimensions.

Highlights

More than half of the world’s population lives in urban areas and this proportion is growing [1]
To demonstrate and quantify benefits for wildlife in the Ōtākaro/Avon River catchment and the OARC through changes in land use/type proposed in the OARC Regeneration
2018 and land use changes in the OARC Regeneration Plan proposed by Regeneration

Summary

Introduction

More than half of the world’s population lives in urban areas and this proportion is growing [1]. Urbanisation is causing habitat loss and fragmentation of complex ecosystems typical of human settlements at the junction of hills, harbours, plains, rivers, and estuaries resulting in biodiversity decline [3,4,5,6,7]. Key biological processes such as breeding, dispersal, and resource utilisation are disrupted [8]. The importance of urban environments for wildlife and their interactions with people is recognised [14]

Methods

Results

Discussion

Conclusion