Quantitative Reconstruction of Local Woodland Vegetation Using Pollen Analysis from a Small Basin in Norfolk, England

Abstract

Pollen analysis from very small basins (< 0.1 ha) provides a basis for more spatially-detailed reconstructions of vegetation than are possible from the analysis of lake or bog sediments. Pollen counts from a small hollow in Oxborough Wood, on the margin of the Fenland and Breckland in Norfolk, were calibrated in terms of tree basal-area, to give a vegetational reconstruction which makes full use of the quantitative pollen data. The core covers the entire Flandrian period. The earliest recorded vegetation apparently resembled modern sub-alpine scrub communities in which Salix is important. After the expansion of Corylus .apprx. 9000 yr ago, the local vegetation was dominated by Pinus and Salix. A lake 20 km distant in the Breckland recorded, by contrast, dominance of Betula and Corylus at this time. More recently than 5000 yr B.P., Tilia cordata composed 30-60% of the tree basal-area within 20 m of the site. The decline of Tilia cordata coincides with a rise in herbaceous pollen. The 19th-century Pinus plantations in the Breckland are evident in the pollen record. The relatively poor condition of the pollen grains is closely monitored but there is no evidence of bias introduced by differential preservation between samples.