Spatial diversity in the mid-Flandrian vegetation history of North Gill, North Yorkshire

The results of investigating a series of 11 pollen and stratigraphic profiles in peats along a 350 m stream section are described. Each profile has a small pollen catchment overlapping little with its neighbour's and the diagrams therefore show fine spatial resolution of the vegetational history. Fine temporal resolution is provided by 1 cm, or for certain sections 1 mm, interval samples. There is evidence that during the Mesolithic distinct patches of the local forest vegetation, of the order of tens rather than hundreds of metres in diameter, were managed by burning and the regular lopping of branches, for periods of up to a few hundred years each. Peat inception is thought to have occurred as early as the 9th millenium BP in some parts of the stream and up to 3000 yr later in others. Lopping and burning was the immediate cause at most sites within the channel of the gill, although fine-scale topographic and geological variation affected the timing. The developing peat was bordered by an alder carr in the lower and middle reaches of the stream. Radiocarbon dating of the mid-Flandrian Ulmus decline shows it to be asynchronous. It was caused by a combination of factors including disease and the affect the mesolithic management practices had had on the soil earlier in the Flandrian.