Changes in plant diversity in a water-limited and isolated high-mountain range (Sierra Nevada, Spain)

Abstract Climate change impacts are of a particular concern in small mountain ranges, where cold-adapted plant species have their optimum zone the upper bioclimatic belts. This is commonly case Mediterranean mountains, which often harbour high numbers endemic species, enhancing risk biodiversity losses. study deals with shifts vascular diversity zones Sierra Nevada, Spain, relation climatic parameters during past two decades. We used vegetation data from permanent plots three surveys GLORIA regions, spanning period 18 years (2001–2019); ERA5 temperature and precipitation data; snow cover durations, derived on-site soil data. Relationships between patterns climate factors were analysed using GLMMs. Species richness showed decline 2001 2008, increased thereafter. slightly but significantly, although not for species. While endemics underwent losses proportional to non-endemics, more widespread shrub increased. Precipitation tended increase last decade, after downward trend since 1960. was positively related richness, colonisation events, cover, negatively disappearance events. Longer duration rising temperatures also increasing numbers, changes. The rapid biotic responses alpine plants indicate tight synchronisation fluctuations, especially water availability. Thus, it rather confirms concerns about losses, if projections combination decreasing hold true.