Pollen analyses of peat showed that species of willow and birch, particularly Betula nana, were the first woody plants appearing on British islands during the pre-boreal period. Then pine followed. In the first half of boreal period extensive stands of hazel were formed. At the same time elm appeared. There is evidence that during the boreal period the area of Europe, including England, was covered with prairie vegetation, which disappeared later under the pressure of hazel and forest trees. In the. middle of boreal period hazel largely degenerated, and the oak immigrated. Toward the end of boreal time pine diminished, white alder (Alnus glutinosa) increased. The first half of post-boreal period is characterized by presence of basswood, elm, oak, holly, beech, hornbeam and pine. During this period occurred a change of climate and extensive formation of soligenous peat. This resulted in local destruction of trees and invasion of swamp vegetation. The spruce immigrated as artificial plantings during the most recent, subatlantic time.