Vulnerability of Pampean Coastal Lizards to Global Change: Divergent Responses of Endemic Specialists and Widespread Generalists

Abstract

The 21st century is defined by converging anthropogenic and biophysical stressors. This study assessed the vulnerability of the endemic specialist lizard Liolaemus multimaculatus and the habitat generalist L. wiegmannii to climate change and land-use/land-cover (LULC) transformation within the Pampean Eastern Dune Barrier up to 2050. Using satellite data, LULC spatial projections, and ecological niche models (ENMs), we quantified habitat dynamics and projected future climatic suitability. Historical analysis (1994–2022) revealed a 20% retraction of active dunes driven by exotic afforestation and urban growth. Projections for 2050 indicate an intensification of these trends, with urban areas accounting for nearly 26% of the regional territory, leading to an additional 17% loss of active dunes. Abundance modeling predicted a decline in L. multimaculatus within the remaining active dunes while ENMs projected a near-total contraction of climatically suitable areas. Crucially, these correlative models may overlook potential physiological or behavioral adjustments; however, the limited dispersal capacity and physical landscape barriers inherent to this specialist likely preclude effective niche tracking. These findings confirm that ecological specialization heightens sensitivity to global change, creating a “double threat” for endemic species. Protecting remnant active dune patches is essential to mitigate the projected collapse of these range-restricted lineages.