Habitat assessment for threatened species in the cross-border region of the Atlantic Forest

ContextIn human-modified landscapes, identification and structural assessment of remaining habitat is required to mitigate habitat loss and fragmentation. In transboundary regions, this analysis must consider ecological limits, as they often do not coincide with sociopolitical boundaries.ObjectivesWe aimed to quantify the cover, configuration, protection status, and spatial overlap of suitable habitats for 24 birds and mammals of conservation concern in the trinational region (Argentina, Brazil, and Paraguay) of the Upper Parana Atlantic Forest.MethodsApplying a multi-scale framework and the random forest algorithm, we built habitat suitability models considering presence-only data distributed across the Atlantic Forest biome and mapped the relative habitat suitability in the trinational region. We quantified habitat coverage and protection at country and regional scales. We also assessed the spatial configuration and overlap of forests predicted to be suitable for the target species.ResultsThe total suitable habitat covered less than 17% of the study region for 20 of the 24 target species. On average, 40.9% of the suitable habitat can be found in Argentina, 30.5% in Brazil, and 28.6% in Paraguay. Only 2.4% of the entire study region is occupied by protected suitable habitat. Protected areas focused on biodiversity conservation showed greater relative coverage of suitable habitat than PAs allowing for multiple human uses. Suitable forests are highly fragmented, especially for threatened species. Nine species showed an average overlap of at least 70% of their suitable forest area in relation to that predicted for the other species.ConclusionsThe remaining habitat of the trinational region is unevenly distributed across countries, with low coverage, low protection, and high fragmentation. Species persistence will require cross-border collaboration to restore, expand, and connect the Upper Parana forests, and our results provide important information to support this.