Burning biodiversity: Wildfire probability and environmental exposure of endemic reptiles in the Trans-Mexican Volcanic Belt

Abstract

Wildfires are increasingly recognized as an important pressure on biodiversity in montane regions. The Trans-Mexican Volcanic Belt (TMVB) supports high reptile endemism, yet the degree to which species’ potential habitats intersect fire-prone environments remains poorly quantified. In this study, we analyzed the spatial and temporal relationships between fire occurrence and reptile habitat by integrating species distribution models, fire risk layers, land cover loss, and landscape metrics across 38 endemic reptile species. From 2001 to 2023, fire-related tree cover loss increased across the region. Associations between annual fire loss and broad-scale climatic indices (Oceanic Niño Index and SPEI) were weak, indicating that climate alone may be insufficient for explaining observed dynamics. These patterns are consistent with an important contribution of human land use, although causation cannot be directly inferred. Spatial overlays showed that notable fractions of the predicted distributions occurred in areas with elevated fire probabilities: ∼12% in the medium category and ∼6% in the high category. Some taxa exhibited particularly large exposures. In environmental space, principal component analyses revealed visible coincidence between reptile habitats and conditions associated with fire; however, the quantitative overlap metrics were generally low, and equivalency tests were nonsignificant. This suggests limited environmental similarity and indicates that fires tend to occur within broader tolerances rather than near predicted suitability optima. After the fire probability was incorporated, many species exhibited a reduction in the number of habitat patches. Taken together, these results highlight the widespread exposure of endemic reptiles to contemporary fire regimes. Integrating disturbance probability with climatic suitability may strengthen conservation planning in rapidly changing montane landscapes.