Geographic range-scale assessment of species conservation status: a framework linking species and landscape features

Abstract

The concept of habitat and spatial extent are key features in landscape ecology. A non-precise definitionof habitat and the wrong choice of the scale can affect model outcomes and our understanding aboutpopulation conservation status. We proposed a framework and applied to five species representing dif-ferent ecological profiles (1) to model species occurrences and (2) to evaluate habitat structure at ninedifferent scale extents from local landscapes to entire species range. Then, we (3) evaluated the scalesensitivity of each metric and (4) assessed if the scale sensitivity of each metric changed according tospecies. Our model was succesfull in predicting species occurrence for all species. When we applieddeductive suitability models, the total area of remaining habitat varied from 83% to 12% of the origi-nal extension of occurrence. On average, the proportion of habitat amount, fragmentation, and carryingcapacity decreased and functional increased as scale extent increased. Habitat amount and fragmentationassessed locally would show the same pattern across species’ range, but carrying capacity and functionalconnectivity – which consider biological features – were affected by the choice of scale. Also, the inclusionof species preferences on habitat modeling diminished commission errors arising from landscape-scaleunderestimation of species’ occurrences. Local landscapes samples were not able to represent species’entire range feature and the way that individuals reach the remaining habitat depends on species’ fea-tures. Species conservation status should be assessed preferably at the range scale and include speciesbiological features as an additional factor determining species occupancy inside geographic ranges.