Pollen Analytical Evidence Relating to the Vegetation History of the Chalk

Pollen data are presented showing that the Chalk Downs around the Lower Ouse Valley in Sussex were well wooded from the early post-glacial until the Middle Bronze Age, c. 1240 bc, and that even then grassland was not the dominant vegetation type. There is also evidence that the downland soils were deeper and probably less calcareous in the early post-glacial. A pattern of temporary vegetation clearances and soil erosion in the Neolithic followed by more permanent effects in the Middle Bronze Age is in agreement with several pieces of evidence from elsewhere in south-east England, but contrasts with the clearance of the central southern Chalk by the Neolithic. Ulmus and Tilia were particularly affected by human activities, and the hypothesis is put forward that they were selectively cleared from the most mesic, base-rich valley soils. Evidence is also given for the post-glacial history of Fagus in the region.