Period in post-glacial (i.e. post-Devensian or Flandrian) times from about 9500 to 7500 BP, which preceded the climatic optimum of early Atlantic times. Pollen records typically show an increasing abundance of thermophilous (warmth-loving) tree species and also indicate the drier, more continental conditions that characterized the ensuing Atlantic period. The early Boreal corresponds to late Pollen Zone V; otherwise the Boreal is linked with Pollen Zone VI, which is sometimes subdivided to give Zones VIa, VIb, and VIc, according to the most abundant tree pollen represented. For Britain, the Boreal period is significant as the last period in post-glacial times in which Britain was joined to mainland Europe by a land bridge across the Dover Strait. See also pollen analysis.