The elm decline at Pawlaw pike in Weardale county Durham: (a detailed pollen analysis)

In a pollen analysis of a peat profile from a bog at Pawlaw Pike, County Durham, a very close sampling technique, by finely sectioning a core, provided evidence of repeated short duration changes in the upland vegetation prior to the reduction of elm in the forest approximately 4,600 years ago. It is suggested that each of these changes correspond to an opening up of the forest which lasted for about 25 years on the average and were possibly due to burning and other pastoral activities of the early herders. Frequent occurrences of charcoal and an increase in the pollen of grasses, ruderals and other cultural species at the respective strata indicate that the forest was possibly being cleared to provide better grazing for livestock. It is furthermore suggested that the early herders introduced goats and sheep as well as cattle into the area as their domestic animals, and that they were instrumental in drastically reducing the elm trees in the forest, by selectively grazing on their seedlings which apparently are more palatable than those of other tree species of the high forest.