The vegetational history of Teesdale

Three radiocarbon dated pollen diagrams have been constructed from different locations within Teesdale. These diagrams provide some interesting regional variations in the vegetational history of the dale. Evidence suggests that a Late-glacial type of vegetation persisted in Upper Teesdale after its replacement in more lowland areas of northern England. In the early Post-glacial pioneer birch and pine woodland spread more quickly in the lowlands than in the uplands of the dale. Similarly, the expansion of the thermophilous trees was slower at the higher altitudes, where pine continued to remain a dominant element of the upland woods. Of particular note was a late pine expansion in Upper Teesdale which occured some 6,800 years ago. During the early Post-glacial the trees migrated up the dale along the sheltered valley of the Tees. Once established the upland woods were less dense than those of the lowlands. There is some evidence for the presence of Mesolithic man on the Moor House National Nature Reserve some 5,900 years ago. Prom this time onwards it is clear that the vegetational history of Teesdale can only be considered in the light of human interference. All diagrams indicate that during the late Post-glacial period woodland clearance became an ever-increasing feature of the vegetational history.