Search

The results of 14C- and 210Pb-dated pollen profiles from the Forest of Bowland, Lancashire are presented, covering the period from the late Iron Age up to the present day. Two notable features of the pollen profile are the apparent lack of a period of large-scale forest destruction during the time of the Norse invasions and the substantial phase of tree clearance towards the end of the Iron Age period. The evidence suggests that the Viking invasions into Lancashire may not have been as destructive as once believed. The invasions were probably gradual, possibly localized (certainly as regards the Bowland area) and seem to have occurred alongside existing populations. Previous pollen-analytical evidence regarding the Iron Age peoples of north-west England has supposed them to have had little effect on their surrounding vegetation. It is now suggested that forest clearance previously assigned to the Romans in north-west England is of Iron Age origin. The pollen profiles presented also reflect several changes of socio-economic conditions that have affected rural populations in Lancashire during the last millennium. An important example is the decimation of populations during the fourteenth and seventeenth centuries. It is suggested that these were caused by the development of subsistence economies, leading each time to a Malthusian crisis. These population declines may also have been exacerbated by outbreaks of plague. The fall in population at both times, is clearly reflected by rising arboreal pollen values, indicative of slackening rates of forest clearance. [ABSTRACT FROM AUTHOR]

The vegetational history of Crose Mere, north Shropshire, is reconstructed by means of pollen analysis, lithostratigraphy and radiocarbon dating. Pollen diagrams from a core representing the Flandrian and Late Devensian are presented. Eleven radiocarbon dates were obtained from the Flandrian and these allowed the estimation of pollen deposition rates from pollen concentrations. The pattern of vegetational changes shows close similarities with those from the lowlands of north-west England notably the appearance of Pinus sylvestris after Corylus avellana, Ulmus and Quercus in the forest succession. The effects of man on the environment are traced and four main agricultural episodes are distinguished after the 'elm decline' at about 5300 B.P. Comparison of pollen percentage and absolute data highlights the problem of interpreting pollen deposition rates from a basin with uneven sedimentation and the possibility of resuspension of freshly deposited sediments. [ABSTRACT FROM AUTHOR]

Pollen originating from small populations of Tilia cordata is largely deposited within a few hundred metres of the trees, so that their presence can only be detected by pollen analysis at sites within distances of this order. Pollen diagrams from such sites show a continuous curve for Tilia pollen extending to the present surface, although the values may be only about 1% of arboreal pollen. Pollen analysis shows that T. cordata was present in the Lake District by about 5000 to 4800 B.C.; it then became plentiful in the southern valleys and extended to reach its present north-western limit, or just beyond, by 3100 B.C., when migration ceased. While the tree was extending its range, it must have been able to produce frequent large crops of fertile seed but subsequently regeneration from seed ceased. After 3100 B.C., the proportion of its pollen initially may increase but then generally decreases. Although there are small recoveries at several horizons, these are not certain evidence of reproduction by seed. Failure to produce fertile seed renders the species particularly sensitive to woodland clearance and has resulted in a decrease in abundance within the Lake District and its virtual extinction in west Yorkshire and south Lancashire. [ABSTRACT FROM AUTHOR]