Modelling semi-aquatic vertebrates' distribution at the drainage basin scale: The case of the otter Lutra lutra in Italy

摘要: Abstract Modelling habitat suitability of semi-aquatic vertebrates for large scale conservation purposes is a particularly challenging task, due to the fine-scale linearity riverine habitats, and ecological continuum represented by riparian aquatic ecosystems, on one side, river its tributaries, other. We advocate that models (HSMs) should represent complexity ecosystems at drainage basin scale, which most relevant spatial unit planning strategies vertebrates. Hence, we developed 3-step GIS-based modelling approach, applied it otter Lutra lutra in Italy illustrate potential applications designing nation-wide strategy. First, built deductive HSM (resolution: 1:250,000, grain: 100 m × 100 m) (100 m buffer around each bank) back-riparian (500 m buffer) areas along rivers. After, created synthetic index Si summarising this information within cells 5 km × 5 km grid superimposed whole country, thus obtaining overview suitability. Both were validated using data distribution, performing sensitivity analysis. Finally, scaled-up provided obtain (Sb). By overlapping layer representing basins occupied otters Sb obtained an effective tool identify be prioritised expansion existing populations, rejoining isolated sub-populations, restoration. The methodology here helps filling gap between urgent needs species, inadequacy traditional approaches species inhabiting world's endangered ecosystems.