I've avoided getting crushed at the Woolworths' closing down sale (or indeed any other melting-down parts of High Street, UK) and focussed instead the effect of the cooler climes after the last ice age on the hill, as set out in Richard's 1988 booklet. My thanks to him and the Trust for the permission to reproduce his oeuvre.
"By 8000 BC the last ("Devensian”) ice age had ended, leaving a tundra-like landscape in southern England in which birches will probably the only trees growing. The "Pre-Boreal" and "Boreal" periods followed ushering in warm, dry conditions last until 6000 BC. With the summer temperatures of recent times today birch, pine and hazel appeared, succeeded by woodlands of oak, alder and elm. In the Atlantic period, 6000 to 3000 BC, with optimal climatic conditions and an increase in moisture, this next oak forest growth reached a peak, covering most of the Midland area and Severn Valley lowlands.
At Crickley Hill the first settlement, of Neolithic farmers, seems to have appeared about 3500 BC. It is only floral remains are poorly preserved carbonised cereal grains, evidence of the occupants' agricultural activity. On other British sites farming brings a decline of elm in the pollen record, suggesting tree felling, and charcoal layers indicate forest burning. The introduction of agriculture affected the floor in many other ways, including the introduction of alien crops and the encouragement of "weeds", "ruderals*" and shrub growth.
The South Atlantic period, from 800 BC, apparently brought climatic deterioration to moister conditions with lower summer temperatures. Late Bronze Age and Early Iron Age farmers continued to expand the existing area of cultivation.
Today the hill is a mixture of mown grassland, less disturbed calcareous grassland and some shrubland. At the back of the hill is a belt of beech woodland. This mosaic of vegetation, with cleared grassland and shrubland areas has probably been the general floral assemblage on the hill since Neolithic times, with only small modifications.
[Illustration: Aurochs, elk, pine-marten and wild boar were common after the last ice age. B Halford]"
No comments:
Post a Comment