Saul Manzano will present the Department of Biological Sciences seminar with a talk entitled, "Arid and biodiverse? A long-term perspective on how landscapes can overcome aridity."

Biodiversity hotspots house approximately 60% of the world’s terrestrial life forms, but only 16% of the land surface area. It is remarkable, however, that many of them lie under arid and semi-arid climates. That is the case of the Mediterranean hotspot.

Glacial refuge during the ice ages? Climate stability during the Quaternary? Many explanations have been suggested to account for the enormous diversity of plant life where very high summer temperatures superimpose on a generalised summer draught. Furthermore, the Mediterranean has seen an aridification trend over the last five millennia. Strikingly, over 25,000 species of plants still thrive there.

Here, we propose an explanation for long-term plant survival in two contrasting, highly biodiverse environments within the Mediterranean hotspot: the coastal Doñana Marshlands and the high Sierra Nevada range (S Spain). Long-term vegetation data, ground-truthed by restoration interventions and traditional ecological knowledge show how internal ecological feedbacks can enhance water supply during arid spells. But does this also happen in the South African biodiversity hotspots?