Identifying multispecies connectivity corridors and the spatial pattern of the landscape

Abstract

The maintenance and enhancement of connectivity for multispecies is a challenging issue for biodiversity conservation and landscape planning. It is well-known that different elements of the landscape matrix provide different levels of permeability to species moving across the landscape, but such effects may be species-specific. Whilst the spatial articulation of connectivity corridors is highly dependent on how we define them, and which species group we intended to provide connectivity for, it is also important to understand the optimal land cover mix to promote the maximum number of species. We demonstrate an approach to (1) identifying multispecies networks and examine how it compares to previous network approaches for a case study city of Sheffield, UK and (2) developing specific proposals for how green networks in Sheffield could be improved. We modelled least-cost corridors for four bird, three mammal and three reptile species. After validating the derived corridors, we created a union of least-cost corridors that identified the multispecies connectivity zones and compared the derived multispecies networks with the pre-existing networks (Sheffield City Council - the Green Network and the Sheffield and Rotherham Wildlife Trust- the Living Don ecological network). We found that a particular mix of land covers (particularly, woodlands, mixed vegetation and unimproved grassland) have a high potential to provide corridors for the maximum number of species around the edges of the city centre or the suburbs. A significant proportion of the Green Network and the Living Don ecological network coincide spatially with these land covers. Based on the comparisons of the derived and existing corridors, we discuss specific proposals for how Sheffield green networks could be improved and which areas to prioritise. Utilising species relevant connectivity models which incorporate a group of species with complementary and contrasting habitat requirements will enable a much more complete picture of potential landscape connectivity across the landscape and more informed decisions for biodiversity conservation and landscape planning.