The palynological and plant macrofossil contribution to the SNF interdisciplinary project “Investigating the ecological and climatic conditions at ice age refugia to assess past and future ecosystem functioning (ECO-ICE)”

During the last ice age, much of Europe was far colder and drier than it is today. As glaciers and frozen soils spread across the continent, many tree species survived only in a few sheltered places where local conditions remained suitable. These natural "safe havens" or “oases”, known as refugia, allowed temperate forest species to persist through thousands of years of harsh climate. After the last ice age ended, the surviving populations spread across Europe and compose the temperate forests we know today. Even though refugia played a crucial role in preserving Europe's biodiversity, many basic questions remain unanswered. For instance, it is still not known exactly whether only southern, Mediterranean refugia existed or if areas north of the Alps in north-western and central Europe also harbored small and hidden refugia of temperate species, undiscovered or with few evidence. The existence of such micro and cryptic refugia of temperate trees north of the southern European peninsulas has been repeatedly questioned, hence this topic remains highly debated.

The SNF-funded ECO-ICE project brings together expertise from (paleo)ecology, (paleo)climatology, (paleo)genetics and dynamic computer modelling to investigate the survival of European temperate forest species during the period from about 28,000 to 14,000 years ago, covering the time before, during and after the coldest phase of the last ice age, termed the Last Glacial Maximum (LGM). The project will study sediments preserved at ten sites across Europe. ECO-ICE comprises four research groups at the Universities of Basel and Bern.  While the other research groups focus on paleoclimates, palaeogenetics and dynamic vegetation modeling, our group is applying palynology and plant macrofossil analyses to reconstruct the past dynamics of vegetation, focusing on temperate species.