Scotland’s Land Cover

Contents

• introduction
• Origins of Land Cover Mapping
• Scottish Biogeography
• Climate
• Geology and Soils
• Time
• Land Cover Mapping
• The Land Cover Map of Scotland
• Future Landscapes of Scotland
• Support Materials
• About

5. Time

Scotland's oldest rocks, dating back some 3,300 million years, bear witness to the extreme age of the earth, to the collision of continents¹⁹, to the force of volcanic activity and the erosive powers of glaciation and associated meltwater.

As the glaciers of the last ice age retreated between 15,000 and 10,000 years ago they revealed, in part, an ice-carved and smoothed landscape. Extensive and substantial quantities of unconsolidated rock and fine-grained materials were deposited by the melting ice and its meltwater. It was on these surfaces that vegetation became established and soils developed.

Initially, the colonising vegetation was Arctic. As the climate warmed, woodland became widely distributed throughout the Scottish mainland, and Arctic communities became restricted to the higher hills and the north. In an unaltered state Scotland would be mainly wooded except on mires where the ground is too water-logged for tree growth or on exposed mountain tops and coastal margins.

Rising sea levels from the melting ice sheet led to the formation of the English Channel some 8,000 years-or-so ago. Britain became severed from continental Europe and so new plant colonisation was reduced.

The distribution of woodland was at its greatest extent around 8000 - 5,000 years ago. Episodes of higher rainfall and lower temperatures promote the expansion of peat-moor and heath, and a retreat of the former forest. We know that peat began to form in Scotland as early as 7600 BC, and believe that periods of increasing cold and wet occurred at about 5500 BC, at about 4000 BC, at about 1350 BC, and at about 800 BC.

The coming of people

The first proven traces of human habitation come from about 9,000 years ago, from the Isle of Rum. The earliest people were Mesolithic hunter-gatherers, but primitive farmers with their stone tools would have found birch woodland relatively easy to clear. From about 5000 years ago Neolithic people cultivated the light upland soils, a process which continued in the Bronze Age. The arrival of Celtic peoples around 2,500 years ago heralded the Iron Age, with technology which made more extensive clearance of forests possible, and with it an appreciable increase in the numbers of grazing animals. The use of fire to clear land for pasture, which had been going on since the mid-Bronze Age, became more frequent. By the time of the Roman invasion of Britain in 43 A.D. (Scotland 79 - 80 AD), Scotland south of the Highland line was probably already mainly open country with farming well established. In remote areas, or on difficult soils, more forest cover would have remained.

The coming of sheep

Pre-industrial farming, through cultivation, grazing and moorland burning, contributed to the dwindling extent of Scottish woodlands. The medieval abbeys ran large flocks of sheep. The goat was ubiquitous in the 17th century. For about one hundred years from the middle of the 18th century, the Highlands were increasingly converted to pastoral use: first as cattle ranches and later as sheep runs. The Highland clearances of the 19th century made way for extensive sheep-rearing, and the subsequent emergence of sporting estates of deer forest and grouse moor.

The industrial and agricultural revolutions

Industrialisation transformed Scottish agriculture, which by 1830 had become one of the most productive systems then known. This involved the drainage of innumerable boggy areas and wetlands, the planting of hedges of hawthorn and windbreaks of beech and sycamore, and cropping systems which employed crop rotation and imported fertilisers. From the mid-1800s onwards population growth in urban areas continued to expand but the rural population fell as a result of migration to the towns.

The 20th century

The present century has been marked by the further mechanisation, intensification and specialisation in agriculture, with increasing output from a shrinking work force. This has been coupled with a marked expansion in urban development, for housing and industry, road transport and utilities. As access has improved, the importance of recreation and tourism have grown. When the Forestry Commission was established in 1919, Scotland’s woodland cover had been reduced to about 5 per cent of the land area, despite substantial tree planting by private landowners in the 19th century. Since then there has been a steady expansion in tree cover, mainly through conifer plantation.

Since the late 1980s there has been a slackening of pressure to expand agricultural production and commercial forestry. A proportion of arable land has been required to be set-aside from production and there has been a reduction in incentives for commercial afforestation. Agri-environmental schemes and Environmentally Sensitive Areas offer incentives to farm in less-intensive ways. Agricultural policy at the end of the 20th Century is drawing back from intensification, with a growing regard for wildlife and landscape. Forestry is being augmented by programmes to enhance and create native woodlands. The design of new forests and their felling programmes take account of landscape character, and opportunities for recreation are frequently incorporated.