Frontiers of Biogeography

Mountains are excellent systems for studying species responses to changing conditions because climatic conditions and related productivity measures change rapidly over short distances (Körner 2007).  Mountains also often have high biodiversity and high levels of endemism (Hoorn et al. 2018, Rahbek et al. 2019), and are typically relatively less disturbed by people compared to flat lowlands. Although new insights about biodiversity patterns associated with mountains and elevation gradients have been achieved (Rahbek et al. 2019) the underpinning mechanistic causes of these biodiversity patterns are still open for debate (cf. Jablonski et al. 2006). This is the underpinning motivation for this special issue on 'Elevational Gradients and Mountain Biodiversity'.