A palynological study of changing woodland limits on the Nidderdale moors

Observations have been made on the stratigraphy of peat deposits at a number of sites varying in aspect and altitude on an area of upland moorland in the West Riding of Yorkshire. Pollen diagrams have been prepared from these sites and a sequence of local pollen zones established. These zones have been subdivided on the basis of changing frequencies in the pollen of species considered to be cultural indicators. An absolute chronology has been established for the pollen diagrams from a series of eight radiocarbon dates. Attempts have been made to relate the sequence of subzones to established archaeological periods and, more recently, to documented historical events. A survey of surface pollen samples was carried out from the moorland and from within the remaining woodland communities on its flanks. The results of this survey have been used in the ecological interpretation of the fossil pollen diagrams. The early forest history of the area and the gradual decline of trees since 2,000 B.C. has been traced. It has been shown that both soil deterioration and human factors have been significant in the reduction of woodland and the establishment of heath.