pollen zone

pollen zone (pollen-assemblage zone) Characteristic pollen-and-spore assemblage classically considered indicative of a particular type of climate which was assumed to be typical of a fairly extensive geographic region. Changes from one group of pollens to another characteristic assemblage are used to define pollen-zone boundaries. The standard British ( Godwin, 1940) and very similar European post-glacial (i.e. late Devensian and Flandrian) chronology recognizes eight major pollen zones, Zones I–III being the characteristic late glacial sequence: Older Dryas (I), Allerød (II), and Younger Dryas (III). More recently, based on N. American work, the importance of regional variation in the typical zone floras has been acknowledged, and a more flexible approach to pollen-zone definition applied. Pollen-assemblage zones are defined in terms of their pollen and spore profiles alone for a particular site, and initially without reference to or matching with the standard zone models with their strong climatic links. This has enabled local changes, often anthropogenic rather than climatic, to be elucidated more clearly.