Patterns and dynamics of European vegetation change over the last 15,000 years

Thomas Giesecke (1) , Simon Brewer (2) , Walter Finsinger (3) , Michelle Leydet (4) , Richard H. W. Bradshaw (5)

1 Department of Palynology and Climate Dynamics
2 University of Utah
3 UMR ISEM - Institut des Sciences de l'Evolution de Montpellier
4 IMBE - Institut méditerranéen de biodiversité et d'écologie marine et continentale
5 University of Liverpool

Aim: Palaeoecological reconstructions document past vegetation change, with estimates of fast shifts in species distributions. The resulting rates of plant spread are often not matched by model simulations of climate-driven vegetation dynamics. Genetic surveys of extant plant populations document directions of the post-glacial spread of trees, challenging traditional interpretations. Our aim is to examine an updated continental pollen data set from Europe in the light of the new ideas about vegetation dynamics emerging from genetic research and vegetation modelling studies. LocationEurope. Methods: We use pollen data from the European Pollen Database (EPD) to construct interpolated maps of pollen percentages documenting changes in the distribution and abundance of major plant genera and the grass family in Europe over the last 15,000years. Results: Our analyses confirm high rates of post-glacial spread with at least 1000myear(-1) for Corylus, Ulmus and Alnus and average rates of 400myear(-1) for Tilia, Quercus, Fagus and Carpinus. The late Holocene expansions of Picea and Fagus populations in many European regions cannot be explained by migrational lag. Both taxa shift their population centres towards the Atlantic coast suggesting that climate may have played a role in the timing of their expansions. The slowest rates of spread were reconstructed for Abies. Main conclusions: The calculated rates of post-glacial plant spread are higher in Europe than those from North America, which may be due to more rapid shifts in climate mediated by the Gulf Stream and westerly winds. Late Holocene anthropogenic land use practices in Europe had major effects on individual taxa, which in combination with climate change contributed to shifts in areas of abundance and dominance. The high rates of spread calculated from the European pollen data are consistent with rapid tracking of early Holocene climate change by common tree species, documenting that plants can spread fast tracing their climate space, regardless of their dispersal strategy.

Mots clés: spread of trees; pollen; EPD; post-glacial; migrational lag; global warming; Europe

Domaines: Biodiversité et Ecologie; Milieux et Changements globaux; Géographie

Thomas Giesecke, Simon Brewer, Walter Finsinger, Michelle Leydet, Richard H. W. Bradshaw. Patterns and dynamics of European vegetation change over the last 15,000 years. Journal of Biogeography, 2017, 44 (7), pp.1441-1456. ⟨10.1111/jbi.12974⟩. ⟨hal-01681629⟩