A multi-species approach for assessing the impact of land-cover changes on landscape connectivity

Abstract

International audienceLand-cover changes (LCCs) could impact wildlife populations through gains or losses of natural habitats and changes in the landscape mosaic. To assess such impacts, we need to focus on landscape connectivity from a diachronic perspective.We propose a method for assessing the impact of LCCs on landscape connectivity through a multi-species approach based on graph theory. To do this, we combine two approaches devised to spatialize the variation of multi-species connectivity and to quantify the importance of types of LCCs for single-species connectivity by highlighting the possible contradictory effects.We begin with a list of landscape species and create virtual species with similar ecological requirements. We model the ecological network of these virtual species at two dates and compute the variation of a local and global connectivity metric to assess the impacts of the LCCs on their dispersal capacities.The spatial variation of multi-species connectivity showed that local impacts range from −6.4% to +3.2%. The assessment of the impacts of types of LCCs showed a variation in global connectivity ranging from −45.1% for open-area reptiles to +170.2% for natural open-area birds with low-dispersion capacities.This generic approach can be reproduced in a large variety of spatial contexts by adapting the selection of the initial species. The proposed method could inform and guide conservation actions and landscape management strategies so as to enhance or maintain connectivity for species at a landscape scale

Environmental impact assessment of development projects improved by merging species distribution and habitat connectivity modelling

“…Using a habitat-oriented approach based on expert opinions or literature is one alternative (Avon and Bergès, 2016;Mimet et al, 2016;Sahraoui et al, 2017). This approach has the advantage of making the ecological network visible and understandable to all the territory's stakeholders.…”

“…To indicate the local contribution of each patch to the global PC index, we used the local metric of interaction flux IF (Eq. 3) (Sahraoui et al, 2017).…”

The r toolbox grainscape for modelling and visualizing landscape connectivity using spatially explicit networks

“…And retrospectively: how has the landscape shaped the observed demographic and genetic structure of the populations? Landscape connectivity models have been used for a variety of purposes including: conservation planning, managing landscape change and habitat fragmentation, constructing corridors and protected area networks, understanding impediments to dispersal and gene flow, estimating the availability of ecosystem services to agriculture, helping wildlife populations adapt to climate change and, reducing risks associated with the spread of human diseases or invasive species (Albert, Rayfield, Dumitru, & Gonzalez, ; Auffret et al, ; Castillo et al, ; Lechner, Sprod, Carter, & Lefroy, ; McGuire, Lawler, McRae, Nuñez, & Theobald, ; Perry, Moloney, & Etherington, ; Rayfield, Pelletier, Dumitru, Cardille, & Gonzalez, ; Sahraoui, Foltête, & Clauzel, ; Saura et al, ; Sousa & Small, ; Travis Belote et al, ; Watts et al, ).…”

Modelling in the Context of an Environmental Mobilisation: A Graph-Based Approach for Assessing the Landscape Ecological Impacts of a Highway Project

“…However, few studies have attempted to spatialise the potential connectivity of several animal species at any point in the territory. This kind of approach has been explored by Sahraoui et al (2017) by assessing the retrospective impact of different land use changes. Currently, very few studies use this type of spatial representation to assess the ecological impact of future development projects.…”