Assessing the species habitats in Colombia’s tropical dry forest over a 20 years period

Maria Isabel Arce Plata , Natalia Norden, Jaime Burbano Girón, Guillaume Larocque, María Camilla Diaz-Corzo, Susana Rodríguez Buriticá, Germán Corzo, Timothée Poisot 

Countries worldwide are collaborating under the Convention on Biological Diversity to address biodiversity loss. As part of this effort, the monitoring framework of the Kunming-Montreal Global Biodiversity Framework (K-M GBF) includes a set of indicators to track progress toward its goals and targets. One of these is the Species Habitat Index (SHI), a component indicator supporting Goal A, which measures changes in habitat extent and connectivity for multiple species. In this study, we applied the SHI to assess the status and trends of species' habitats in Colombia’s Tropical Dry Forests (TDF) from 2000 to 2020. These forests have undergone extensive degradation and fragmentation, being reduced to less than 2% of their original extent in some regions, with much of their original extent reduced to small, isolated patches. Overall, we found that Colombia’s TDF has lost nearly one-third of its cover since 1990, despite modest gains between 2010 and 2018. Most forest loss resulted from conversion to pasture, although some recovery of degraded forest was observed. We calculated SHI values for 755 bird (237), mammal (68), and plant (450) species using land cover data. To assess habitat connectivity, we used GISFrag and Omniscape and compared outputs. Across the potential TDF area, habitat and connectivity declined by approximately 20% between 2000 and 2020, leaving only ~800,000 ha of habitat. Species associated with natural habitats showed lower SHI values than those adapted to artificial environments, and mammals, many of which are threatened, had the lowest scores overall. We also evaluated the representativeness of protected areas and found that less than 13% of the remaining habitat lies within protected areas. The increasing extent of successional forests, now over 1,000,000 ha, presents an opportunity for ecological restoration. These results underscore the urgency of implementing nature-based solutions. Regionally tailored strategies will be critical to maintaining connectivity in this highly fragmented ecosystem.