Integrating species distribution modeling and climate projections to predict ant species redistribution

As ecologically dominant keystone species, ants play critical roles in ecosystem functioning and trophic interactions. This study examines current and future distribution patterns of five ant species (Cataglyphis nodus, Crematogaster subdentata, Lasius neglectus, Messor platyceras, and Messor syriacus) across central Iran's forest, grassland, and human-modified landscapes. Species were collected along an ecological gradient extending from the central Zagros Mountains to Gavkhouni Lake on the Iranian Plateau. Using an ensemble species distribution modeling (SDM) approach incorporating five machine learning algorithms (Generalized Additive Model, GAM, Generalized Boosted Model, GBM, Generalized Linear Model, GLM, Random Forests, RF, and Extreme Gradient Boosting, XGBOOST), we evaluated habitat suitability under climate change scenarios (Shared Socioeconomic Pathways, SSP126 to SSP585, 2021-2040, 2041-2060, 2061-2080, 2081-2100). Environmental predictors included 19 bioclimatic variables, topography, and NDVI-derived vegetation indices to assess current habitat suitability and to project future distributions under climate change scenarios from 2021 to 2100. Our best ensemble model (GBM) showed strong predictive performance (Receiver Operating Characteristic, ROC,: 0.78-0.90; max True Skill Statistic, TSS,: 0.75), identifying temperature variables, precipitation metrics, and the Normalized Difference Vegetation Index ,NDVI, as key environmental drivers. Projected range changes (2021-2100) revealed species-specific responses: C. nodus, C. subdentata and M. platyceras showed maximum gains and losses under SSP126 and SSP585 respectively in different period; L. neglectus displayed extreme reduction potential, exhibited maximum gains and losses under SSP245 and SSP585 respectively in different period; while M. syriacus showed relative stability maximum gains and losses under SSP370 and SSP585 in different period, highlighting significant interspecific variability in climate change vulnerability across emission scenarios. Niche breadth analysis identified C. nodus and M. platyceras as "winners" transitioning toward generalist strategies, while C. subdentata remained a vulnerable specialist. These findings highlight: (1) substantial interspecific variability in climate vulnerability, (2) the critical influence of emission scenarios on distributional outcomes, and (3) the importance of vegetation-mediated microclimates in buffering climate impacts. Conservation efforts must prioritize microhabitat preservation and landscape connectivity, particularly for functionally important species. The results provide crucial insights for conservation prioritization in arid land ecosystems under global change.