The history of the vegetation and flora of Widdybank Fell and the Cow Green reservior basin, Upper Teesdale

Abstract

The stratigraphy of all the major peat deposits on Widdybank Fell and in the Cow Green Reservoir Basin, Upper Teesdale, has been investigated and pollen diagrams prepared. This evidence shows that peat has been forming in the area from the end of the late-glacial, zone III, until quite recently, zone VIII, with the exception of a short period between about 10000 and 8800 B.P. The late-glacial vegetation was replaced only slowly by woodlands which at this altitude never developed a closed canopy even during the post-glacial climatic optimum . From 5000 B.P. onwards these woods were gradually replaced by blanket bog on the drift derived soils and later by grassland on the more porous limestone. Pollen grains from many of the rare species which grow in the area today, e.g. Gentiana verna and Dryas octopetala , have been found in the post-glacial deposits at several different levels including those which formed when the woodlands were at their most dense, thus demonstrating their presence in the area throughout the postglacial and confirming the relict nature of the Teesdale flora.