Coping with species’ perception of barriers: an assessment of landscape fragmentation

Landscape fragmentation (LF) is a major consequence of human actions. LF can be caused by transport and mobility infrastructures (TMIs), which have effects on ecosystem continuity, flora, and fauna. TMI-driven LF can be assessed using indices, such as the Infrastructural Fragmentation Index (IFI), which reports on the divisions brought by the road and railway network. By contrast, the IFI does not fully consider other crucial issues, such as the so called ‘barrier effect’, i.e. the way an animal actually perceive TMIs. Thus, we aim to build and apply the Barrier Fragmentation Index (BFI), a modified IFI-based index, able to quantify the LF as perceived by specific target species. We test the BFI for Sardinia choosing the hedgehog (Erinaceus europaeus L.). Outcomes show that IFI varies with higher absolute values than the BFI. However, BFI and IFI display similar trend lines with a different sensitivity to the changes of their components. Mitigation strategies aimed at defragmenting the landscape could be planned in areas with high BFI values. However, some critical issues need to be dealt with in the next steps of this research in order to measure a more accurate BFI.