Radiocarbon Dates and Vegetational History of the British Isles

Summary Radiocarbon dates for a number of pollen analytic features marking important vegetational changes in the Post‐glacial of the British Isles are plotted in two figures (Figs. 2 and 3, summarized in Fig. 4). Despite the limitations of the radiocarbon method it becomes clear, where sufficient dates are available, that most of the vegetational developments of the earlier part of the Post‐glacial are diachronous. Some of these changes have been used as pollen zone boundaries. The elm decline appears synchronous, however, within the limits of the methods, and the final pine decline in Ireland, which is shown to be older than supposed by Jessen (1949), appears to be one of the least diachronous of the horizons examined. Marked differences in the dates of similar vegetational changes within a small area, and between upland and lowland, are pointed out.