On the Geological History of the Prehistoric Flora of Sweden

Abstract

FIFTY years have passed since the Danish Professor, Japetus Steenstrup, presented to the world his masterly researches on the history of Denmark's peat-bogs. These researches clearly demonstrated that the forests of Denmark had suffered remarkable variations. The oldest forests had consisted chiefly of aspen (Populus tremula), next, for a long period, of Scotch fir (Pinus sylvestris), then of oak, and, finally, of alder (Alnus glutinosa). Remains of the beech—now Denmark's chief species of tree—are, however, entirely absent from the peat-bog. Consequently, it must have been the last to immigrate. It was a natural surmise—and one even advanced by Steenstrup—that the changes referred to were connected with a gradual softening of the climate, a view defended, too, by Prof. Forchhammer.