On the uplands, cultivation may extend to a height of 1000 ft. or more, but above this level, and to a considerable extent below it also, most of the land is occupied by natural or semi-natural plant communities. Except at the highest altitudes and in the most remote places the great bulk of the upland country has been used for pasture. Much of it, like many of the lowland commons, is covered with a vegetation of wild grasses and is known as 'hill' or 'rough' grazings, mainly used for sheep rearing, to serve the great wool and cloth industries of past centuries. Here are included the downs of the south (which scarcely reach l000ft.), much of the uplands of the south-western peninsula, and the hills and mountains of Wales, the north of England, the Scottish Southern Uplands, and the Highlands. Most of the grassland of these hill grazings owes its present condition largely to the continual nibbling of the sheep. Great tracts of land in the north and west, however, are not covered by pure grass vegetation but by heather, bilberry and similar plants, often mixed with grasses; and these moorlands are frequently preserved as grouse moors which are periodically fired to promote new growth of the heather, and in the Highlands as deer forest. Many of the moorlands are also more or less grazed., Great tracts of this high-lying country, too, are occupied by bog or boggy moorland covered with cotton-grass, deersedge and similar plants, especially in the very wet climate of the north-west. Above 2000 ft., and especially above 3000 ft., the so-called 'alpine' vegetation of the higher mountains begins to appear. This consists largely of lichens and mosses but includes a number of flowering plants peculiar to this region, and is little, if at all, altered by human activity.
Thus the uplands of Great Britain are very largely covered by vegetation which is ' wild' in the sense that the plants composing it are native to the country and have come there by themselves, but much of which nevertheless owes its particular character to human agency, mainly the grazing of sheep and cattle. Sir George Stapledon has shown that the hill grasslands can often be made much more productive as sheep pasture by ploughing, manuring, and sowing with pedigree strains of grasses and clovers. So far as this is done, and it has not yet been done on any large scale, the vegetation will cease to be 'wild', though the general aspect of the country will not be greatly altered.