A comparison of variations in forest imposition in the north Pennines between the sub-boreal and Atlantic periods

Abstract

The aim of this investigation was to test whether the patterns of latitudinal variation observed in the Atlantic forests of the North Pennines were maintained in the Sub-Boreal. Nine Sites were selected along a north-south transect. Pollen analyses of the Sub-Boreal at these sites were compared with analyses for the Atlantic. The results show that Tilia and Fraxinus maintain significant clinal variations during both periods. During the Atlantic elm was more abundant to the south. This pattern was not observed in the Sub-Boreal. Alnus showed distinct clinal Variation in the Sub-Boreal but not the Atlantic. No clinal variations were seen in Quercus, Betula, Corylus or Salix in either period. Quercus, Betula, Alnus and Corylus contributed most to within-site variation during the early Sub-Boreal. The results indicate that during the Sub-Boreal Corylus, Betula, and Quercus were influenced by local conditions, Tilia and Fraxinus by regional conditions and Alnus by some combination of both.