Mechanistic understanding of ecological niche overlap in two sympatric lizard speciesDajčman, Urban (Avtor) Žagar, Anamarija (Mentor) Urzelai, Urtzi Enriquez (Komentor) ecological nichemechanistic modelingabiotic nichebiotic nichecoexistencesyntopyPodarcis muralisIberolacerta horvathiparasitesKaryolysusAbiotic and biotic elements of the ecological niche are key to understanding species coexistence. This dissertation explores which factors enable the coexistence of two closely related lizard species – Horvath’s Rock Lizard (Iberolacerta horvathi) and the Common Wall Lizard (Podarcis muralis). Based on ecological niche theory, the study investigates how microclimate, physiology, parasitism, and interspecific competition shape their coexistence along an elevational gradient. The research integrates fieldwork, parasitological and ecophysiological laboratory analyses, and mechanistic modelling. Parasite identification and prevalence analyses revealed higher infection rates of I. horvathi with Karyolysus parasites, particularly at sites where the two species coexist. Physiological data shows adaptations of both species to different altitudinal conditions, with hemoglobin concentration in P. muralis increasing with elevation. Mechanistic models combining microclimatic data, biophysical models, and dynamic energy budget theory show that mid-elevations are most favorable for both species due to environmental heterogeneity. Under different competition scenarios, the subordinate species I. horvathi exhibited lower body temperatures and delayed reproduction. Climate change may affect the outcomes of competition in unpredictable ways; simulations suggest that thermal competition may weaken under higher environmental temperatures. The dissertation presents an innovative approach to mechanistic modelling of interspecific competition and provides an integrated framework for understanding the coexistence of similar species and their responses to climate change.[U. Dajčman]20252026-01-21 07:15:15Doktorsko delo/naloga178188sl