High-mountain plant-pollinators interactions: the case of the narrow endemic alpine plant Androsace brevis (Hegetschw.) Ces. (Primulaceae)

Climate change is a key threat to biodiversity. In Europe, plant species that most suffer its effects are those restricted to mountains environments. Some of these are characterized by a very early flowering, that occurs just after snowmelt. An emblematic example of that is Androsace brevis (Primulaceae), a narrow endemic species that lives only on peaks and ridges of siliceous mountains above 2000 m a.s.l. in the western Alps (Lombardy) and adjacent Switzerland (Ticino) within an area of 800 km2. Climate warming represents a serious menace to this species, since the upward shift of its range is almost impossible. Moreover, an anticipation of its already very early flowering could cause mismatches with pollinators. We investigated the reproductive biology of A. brevis and the role of arthropods as pollinators through the identification of flower-visiting arthropods and quali-quantitative palynological analysis to discover the main pollinators of this species and reconstruct the pollination network that characterize these high-altitude ecosystems in early season. We demonstrated the important role of Diptera Anthomyiidae and Hymenoptera Apoidaea as pollinators of A. brevis and we assessed the taxa spectrum active on its flower. These results are important to explain the pollination biology of Androsace brevis and can provide the basis to develop conservation plans applicable also to other threatened alpine species. Studying the “web of interactions” is fundamental to evaluate possible mismatch that this kind of species could suffer by climate change, with serious repercussions on both plant and animal species, dependent from this relationship.