Assessing Habitat Suitability and Exposure of the Endemic Vasconcellea candicans Under Climate Change and Urban Growth in Lima, Peru.

Fog oases (lomas) are vegetation islands that support unique biodiversity in the coastal deserts of South America by capturing moisture from seasonal fog. Despite their ecological importance, they are among the region's most threatened ecosystems, particularly around Lima, where informal urbanisation and climate change drive their degradation. However, endemic plants inhabiting these ecosystems remain understudied under combined climatic and anthropogenic pressure. Here, ensemble species distribution modelling was integrated with urban growth projections to jointly quantify climatic and anthropogenic pressures on habitat suitability for Vasconcellea candicans, an endemic keystone of Lima's lomas. Occurrence records and environmental predictors were used to calibrate an ensemble of five algorithms under SSP2-4.5 and SSP5-8.5 scenarios. Suitability outputs were intersected with current urban land cover and Land Change Modeller projections for 2050 and 2070. Random Forest showed the highest performance (AUC = 0.968, TSS = 0.773), with Temperature Annual Range (bio07) and silt content as the main predictors. The ensemble identified 2891 km2 of current high-suitability habitat; future projections ranged from a 4% loss to a 56% gain by 2070, identifying 2020-2050 as the most critical management window for conservation intervention before urban consolidation forecloses options. Urban expansion has already affected 36.12 km2 of high-suitability habitat and is projected to reach 126.94 km2 by 2070 (+251%), intensifying along the southern peri-urban front, where protected areas coverage remains limited. Formally designating additional lomas units as fragile ecosystems, expanding protection to unprotected high-suitability patches, and enforcing urban growth boundaries are required to prevent further lomas encroachment.