| 释义 |
Preˈboreal, a.
Also pre-Boreal, preboreal.
[pre- B. 1.]
Applied to a European climatic period that followed the Arctic and preceded, or marked the transition to, the Boreal period, and was characterized by the spread of birch and pine forests. Also absol.
1924Jrnl. Linn. Soc. (Bot.) XLVI. 497 (caption) Pollen-spectra... Holland (S.W. Sweden) (preboreal spectrum). 1934New Phytologist XXXIII. 285 Erdtman suggests that it is partly on account of P. montana pollen that the pine maximum in many parts of the continent falls so much earlier than in England (i.e. in the Early Boreal or pre-Boreal). 1956A. L. Armstrong in D. L. Linton Sheffield vi. 101 The known [Mesolithic] moorland sites are usually upon patches of old land surface.., or in the eroded banks of streams and cloughs, where their pre-Boreal age is testified by remains of the Pennine forest lying in the peat above them. 1976Sci. Amer. Feb. 94/2 Sometime between 8300 and 8000 b.c. the cold Late Dryas period was superseded by a warmer period known as the Preboreal. Pine and birch forest reinvaded the European plain from the south, and the reindeer herd, following the retreating tundra, moved off to the north and northeast. |