Pollen Percentage and Influx Analyses in South-East Ireland: A Contribution to the Ecological History of the Late-Glacial Period

Abstract

SUMMARY (1) Pollen analyses of thick Late-glacial sediments at Coolteen, Co. Wexford, and Late-glacial and early postglacial sediments at Belle Lake, Co. Waterford, are described. (2) The pollen diagrams are divided into local pollen assemblage zones, which were distinguished before being related to conventional zonations. Four regional pollen assemblage zones are recognized, spanning the period from 12 500 B.P. or earlier to shortly before 10 000 B.P., and are named the Rumex, Juniperus-Filipendula, Gramineae and Cyperaceae-Caryophyllaceae-Artemisia pollen assemblage zones, respectively. (3) Three regional pollen peak zones spanning the Late-glacial-postglacial transition are also recognized, and named the Gramineae, Juniperus and Betula pollen peak zones respectively. (4) Comparisons are made with features of pollen diagrams from other Irish and British sites, and the chronology of the zones is considered. (5) Radiocarbon dating and the addition of polystyrene microspheres to the samples permitted calculation of pollen influx per cm2 per year. (6) Total pollen concentration and influx, which are very low only in the basal Rumex assemblage zone, are compared with corresponding figures elsewhere. Empirical evidence suggests that concentration is, in some circumstances, more significant than influx. (7) The regional ecological history of south-east Ireland is discussed. The importance of grassland at and prior to 11 000 B.P., the presence of Koenigia and other arctic-alpines towards the end of the Late-glacial period, and the predominance of Quercus rather than Pinus in the early postglacial period are among significant features noted. (8) The evidence presented does not conflict with, and in some respects supports, evidence from fossil Coleoptera elsewhere about Late-glacial climates.