Identifying wildlife corridors for the restoration of regional habitat connectivity: A multispecies approach and comparison of resistance surfaces

Canran Liu,Matt White,Graeme Newell,Andrew F Bennett,Bi-Song Yue

doi:10.1371/journal.pone.0206071

Abstract

Many large-scale connectivity initiatives have been proposed around the world with the aim of maintaining or restoring connectivity to offset the impacts on biodiversity of habitat loss and fragmentation. Frequently, these are based on the requirements of a single focal species of concern, but there is growing attention to identifying connectivity requirements for multi-species assemblages. A number of methods for modelling connectivity have been developed; likewise, different approaches have been used to construct resistance surfaces, the basic input data for connectivity analyses. In this study we modelled connectivity for a multi-species group of vertebrates representative of heavily fragmented forests in north-central Victoria, Australia. For each species, we used least-cost modelling and compared two alternate resistance surfaces, based on species distribution models and on expert opinion, respectively. We integrated the connectivity results across individual species to obtain a multi-species connectivity map for the region. A resistance surface based on expert assessment of the relative use of land-cover classes by the target species was more informative than one based on species distribution models. The former resulted in pathways more strongly aligned with existing patches and strips of native vegetation. In this region, pathways aligned with streams and their associated riparian vegetation have relatively high ecological potential and feasibility to contribute to regional connectivity for the assemblage of forest vertebrates.

Highlights

Ecological connectivity provides the capacity for the movements of organisms, for gene flow, and for range shifts [1,2,3,4], and thereby is a key factor in the long-term viability of populations, for animal species [5]
Linkage Mapper analyses for each species, based either on resistance surfaces derived from species distribution models (SDMs) or expert-assigned scores, produced generally similar results for most taxa when considering the whole study region at a coarse scale (Fig 3 and S1 and S2 Figs)
In more fragmented landscapes in the study area, linkages more closely followed strips of trees when using the expert-assigned resistance surfaces, whereas linkages arising from the SDM-based resistance surfaces displayed more diffuse patterns through the landscape

Summary

Introduction

Ecological connectivity provides the capacity for the movements of organisms, for gene flow, and for range shifts [1,2,3,4], and thereby is a key factor in the long-term viability of populations, for animal species [5]. An ideal method for designing connectivity networks for a region would be to identify linkages or corridors based on empirical observations of the movements of particular focal species of concern [11]. The least-cost path is a contiguous vector of cells that has the lowest cumulative ‘cost’ to an organism, as the path crosses from one point (e.g. a known population or habitat patch) to another [6]. This method has been used in many conservation projects [14,15,16,17]

Objectives

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Results

Conclusion