The age and post-glacial development of the modern European vegetation: a plant functional approach based on pollen data

To assess quantitatively the age of the modern vegetated landscape of Europe and western Asia Minor, and to reconstruct Holocene dynamics in biomes and landscape openness, we convert pollen data into plant functional type (PFT) assemblages and interpolate the data in space and time with a 4D thin plate spline. We then assess overall vegetation change using the squared chord distance metric, changes in potential natural vegetation using the biomisation method, and changes in landscape openness by calculating the arboreal pollen PFT percentage. The age of the modern European vegetated landscape varies in space; while much of lowland Europe dates to similar to 2,000 cal years bp, some areas have remained unchanged since the beginning of the Holocene; on average, the European vegetated landscape is similar to 4,000 years old. Though the (PFT) assemblage became continuously more similar to present, biome assemblages changed in northern and southern Europe but stayed relatively constant in central Europe. Landscape openness as approximated by arboreal PFT % increased until the mid-Holocene and then returned to early-Holocene conditions by modern times. The temporally continuous dominance of forest biomes suggests climate remained favourable to forest cover across Europe throughout the Holocene. Nevertheless, arboreal PFT % decreased significantly between the mid-Holocene and the present, requiring a non-climatic explanation, which can be offered by disturbance from human activity. Thus, human activity may have been a main driver of European vegetation dynamics since the mid-Holocene, suggesting it should be included in future conceptions of "natural" European vegetation dynamics.