Rapid early-Holocene migration and high abundance of hazel (Corylus avellana L.): alternative hypotheses

Abstract

1. The rapidity of the early-Holocene range expansion of Corylus and the relative abundance of this taxon during the early Holocene are striking features of northwest European pollen diagrams. Several hypotheses have been put forward to account for one or both of these phenomena. 2. Seven general classes of hypothesis are discussed and the evidence relating to each briefly reviewed. 3. It is concluded that the unique character of the early-Holocene palaeoenvironment can probably account for the earlier expansion of Corylus, as well as for its relative abundance at this time. 4. The apparent rapidity of the expansion may, however, in part be an artefact of ‘plateaux’ in the radiocarbon timescale at c. 10 000 and 9500 BP.