Alpine plants of different micro-habitats and climate change

Climate change has a strong impact on biodiversity and in the last decades it has been one of the major topics in biodiversity research and conservation biology. The past climatic oscillations, especially during glacial (cold) and interglacial (warm) periods of the Pleistocene (from 2.6 million to 11,700 years ago), had strong impacts on distribution ranges, population sizes and local persistence or extinctions of plant and animal species. To predict the impact of the ongoing climate change on species, we can assess the reaction of species to past climate changes. Using genetic data of different populations of many species allows us to infer changes in their population sizes in the context of climate change. Alpine biota (i.e., biota of high elevations above the treeline) are considered to be among the ones most strongly affected by global climate change, and alpine habitats are perfectly suited to investigate the impacts of this phenomenon on biodiversity. Micro-topography on alpine slopes determines snow cover distribution, and many studies have documented the essential influence of snow distribution patterns on alpine vegetation types and their species composition. With global warming, snow cover duration will decrease in general, and consequently, species and also vegetation types adapted to shortly snow-covered grounds may gradually shift to snowbed communities adapted to long snow- covered grounds. In this project, we are looking for the impacts of glacial and post-glacial periods on the biogeographic history of alpine species of the Alborz mountain range. This mountain is located in the Irano-Anatolian global biodiversity hotspot, which harbours a high amount of endemic species. Using 16 alpine species adapted to different micro-habitats in the gradient of snow-melting time, we will assess population responses of these species to Pleistocene climate oscillations. In most of the previous studies the role of micro-habitats on the impact of climate change on alpine species has been mostly neglected. We will test the hypotheses that during postglacial warming snowbed species have experienced smaller population sizes due to habitat reduction (long snow-cover habitats), whereas alpine dry ridge habitat species have experienced larger population sizes due to expansion of suitable habitats (short snow-cover habitats). We developed this hypothesis based on the results of our last project that showed the response of mountain species to past climate oscillations to be independent from their elevational zones and rather be affected by their micro-habitats.