Identifying Quaternary glacial refugia has been a major focus of biogeographical research efforts over the last century. The concept of refugia presumes a contraction in species range to a particular geographic area along with a reduction in its abundance due to unfavourable environmental conditions. The Balkan Peninsula represents one of the three southern European glacial refugia where biodiversity persisted throughout the climatically unstable Quaternary period.

In a recent study published in AoBP, Glasnović et al. combined species occurrence data with present and last glacial maximum environmental conditions. They coupled this with spatial analysis of phenotypic plasticity of floral characters to reveal the intricate biogeographic patterns of the endemic plant Edraianthus tenuifolius within the Balkan Peninsula. The species showed patterns of geographical variation that strongly support the ‘refugia within refugia’ concept, which assumes environmental heterogeneity over time and space within larger refugia. Both environmental niche modelling and the geographical variability of morphological characters suggested spatial partitioning, indicating the potential presence of two separate refugia during the LGM. The results from this work support the findings of previous studies that recognised refugial areas for thermophytic plant taxa during the glacial events of the Pleistocene. However, detecting areas that represent potential ice age refugia is just the beginning of understanding biodiversity processes on a geographical level. Further efforts are now needed to address the mechanisms that have led to present day-diversity in terms of environmental changes and ecological processes through recent Earth history.

Researcher highlight

Peter Glasnović is a botany enthusiast, who obtained a BSc in Biology and Chemistry from the University of Ljubljana, Slovenia in 2006. In 2017 he completed a PhD in biogeography at the University of Primorska, Slovenia under the supervision of Professor Boštjan Surina and Professor Valentina Brečko Grubar.

Peter currently works as an assistant at the Faculty of Mathematics, Natural Sciences and Information Technologies of the University of Primorska, Slovenia. He is involved in courses of Systematic Botany, Biogeography and GIS. His scientific interests are plant biology and geographical patterns of plant diversity in the Mediterranean and in the Balkan Peninsula.