A study of the vegetational history of Widdybank Fell, in Upper Teesdale

Abstract

A study was made of the vegetational history of Widdybank Fell, Upper Teesdale, using the techniques of macrofossil, stratigraphic and pollen analysis. The study was designed to investigate (a) the Post glacial history of the vegetation; (h) the relationship of this history with the survival of the present day Teesdale flora; (c) the age of the blanket peat which now covers a large area of the Fell. Peat growth began in hollows at the end of zone III and continued throughout the Boreal period. Evidence from the pollen diagrams shows that the Fell was covered by open woodland during zones VI and Vila. Throughout the Post-glacial period, herbaceous species, including many characteristic of open grassland habitats, maintain high values, equalling the values for tree species. The Atlantic period is characterised by very slow peat growth with oak, elm and alder as the dominant tree species. Radio-carbon dates taken from Tinkler's Site suggest that peat growth became more rapid and widespread during the Sub-boreal period, about 1440 BC. The major development of blanket peat took place towards the end of zone Vllb and during the following Sub-Atlantic period. The increase in herbaceous pollen types began towards the end of zone Vllb with a major rise at about 620 BC. Evidence from the pollen data suggests that the increase in open habitats and deforestation of the Fell was directly connected with an increase in human utilization of the land. The relict species of the Teesdale flora survived the Post-glacial forest maximum in an open woodland condition and spread on to their present grassland habitats from the end of zone Vllb onwards as human activity and climatic deterioration created tracts of open grassland and peat areas.