Unravelling biology and ecology of the endangered endemic alpine plant Androsace brevis (Hegetschw.) Cesati (Primulaceae) by a multidisciplinary approach

Background and Aims – High-mountain ecosystems are strongly influenced by climate change, affecting biodiversity at all levels, from genetic diversity of populations to changes in the web of interactions. We propose Androsace brevis (Hegetschw.) Ces. as a model species to address biogeographic issues and investigate biotic interactions in high-mountain ecosystems threatened by climate change. Androsace brevis is a Southern Alpine narrow endemic plant growing above 2000 m showing a very restricted distribution, with scattered populations of limited size. Climate warming could represent a serious threat for this species, since an upward range shift is almost impossible. Moreover, it flowers very early, in a critical moment for plant-pollinator interactions. Methods – We investigated the geographic distribution, the reproductive strategies, and the genetic variability of A. brevis through nSSR markers. Moreover, we studied the role of arthropods as pollinators by exclusion experiments, identification of flower-visiting species, analysis of their behavior through video recording, and palynological analyses. Finally, we evaluated the presence of a possibly endophytic symbiotic bacterium by molecular techniques. Results – We clarified the reproductive biology of A. brevis, the extent of allogamy, autogamy and vegetative reproduction, the genetic structure of populations, the roles of flowervisiting arthropods. We also identified a possible symbiotic bacterium: preliminary sequence analysis revealed protein functional domains likely involved in the symbiotic relationship with the plant. Conclusions – Our data offer new insights into the biology of A. brevis and the biogeography of the Southern Alpine area, and help to reduce the current lack of knowledge about high-altitude ecological interactions, a key aspect for the conservation of Alpine biodiversity. Our data could help to make prediction about future scenarios for the survival of Alpine species under a warming climate.