An investigation into the recent vegetation history of Great Wood, near Eggleston Co. Durham using fine resolution pollen analysis of Mor humus and relevant historical evidence.

Abstract

This study investigated the recent vegetation history of an ancient woodland, Great Wood, near Eggleston Co. Durham which has been part of the lands of Eggleston Hall since at least 1614. Mor humus was extracted from two sites within the woodland canopy and consecutive 1cm samples were analysed from each sediment. The reasons for this fine resolution sampling was firstly, because the soil profiles were only between 14-20cms and only represented a time scale of a few hundred years, and secondly to provide fine temporal resolution to correspond with the fine spatial resolution obtainable under a closed canopy. Sediment analysis was undertaken to investigate the stratification of the soil in order to identify signs of disturbance. Mor # 1 proved to be highly stratified, whereas as mor # 2 was less stratified, possibly disturbed and had signs of charcoal at the lowest levels. It was therefore concluded that mor # 2 only represented part of the time scale that mor # 1 illustrated, as it was a more recently formed humus, the earlier part having been burnt away. An absolute time scale was not used but a relative time scale was assigned using documentary and anecdotal historical evidence. This took into account the development of the nearby village and the social and economic changes of the region, and also the association of the woodland with Eggleston Hall and the consequent utilisation of the woodland for timber and recreational purposes. The pollen record of mor # 1 was thought to represent the vegetation history from approximately 1750 to the present time, whereas the pollen record of mor # 2 shows the vegetation history from the late nineteenth century onwards. This time scale was deduced from the following:1. There were signs of a more open canopy, due to a greater proportion of herb pollen to tree pollen, and evidence of pollen representing a more regional source area such as Triticum and possibly Calluna. This was thought to represent 1750- 1820 when tillage increased in importance and there were reports of arable activity in the adjoining townfield probably causing a reduction in grazing pressure in the wood and allowing regeneration. This was promoted by the Enclosure Act in 1785, an attempt to establish mineral rights and to make the dales more commercially viable for agriculture and was a result of marginal land being used for tillage during the Napoleonic wars. However, signs of succession and canopy closure began to develop and there were also some signs of management deduced from Fagus pollen appearing and documentary evidence of the path construction through the woods.2. The herb pollen to tree pollen ratio began to fall and canopy closure continued but was not thought to be complete, due to selective management and extraction of timber. The disappearance of Triticum was believed to be due to a change in agricultural trends. Fagus pollen which was quite significant, disappeared abruptly due to the trees in the vicinity of the site being removed.3. Complete canopy closure shown by a consistently high tree pollen to herb pollen ratio with Quercus dominating, arose when management of the wood was abandoned in the 1920's.The fine resolution obtained, both temporally and spatially, demonstrated that mor humus was a useful medium for pollen analysis and with consideration of the underlying principles and mechanisms, meaningful interpretation of the pollen record was possible. Problems encountered with extraction of samples and during processing were discussed.