The largest of the geographical regions, the Highlands embrace a variety of
rock types which give rise to a most diverse landscape and soil pattern.
Again, the lithology of the rocks, the structure into which they have been
formed and their chemical composition influence their response to a
geomorphological process. Undoubtedly the principal event responsible for
creating the landscape has been the Pleistocene Glaciations. Typical U-shaped
valleys and rugged, highly dissected terrain with relatively narrow deep lochs
within rock basins gouged out by the ice contrast with distinctive plateaux in
central areas with smooth surfaces covered by vast deposits of intact and
deeply-eroding peat. Around the deeply indented fjords of the north and west,
steep, often rock or boulder strewn slopes arise from the waters edge and the
sequence of high ridges separated by deep glens create a distinctive but, at
times, repetitive landscape. All of the highest mountains in Scotland are
present within this region.
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Glacially eroded landscape
along west coast of Scotland |
Glaciated U-shape valley in upper reaches of River Dee, Lairig Ghru |
Glacial moraines in valley bottom
and rock controlled hill slopes,
Central Perthshire |
Steep slopes, the possible
presence of outcropping rock or boulders and soils in which peaty, wet
surface horizons create workability problems, all combine to impose
serious restrictions on land use. Flat land associated with alluvial
deposits and/or river terraces represent the best sites for arable
farming, such land often forms ribbons within major valleys and merges
into improved grassland within the foothills. With increase in altitude,
the resultant higher rainfall, lower temperatures and greater exposure all
influence the chemical, physical and biotic processes in the soil such
that peaty soils are widespread outwith the cultivated land. These areas
are often set aside for rough grazing or the more specialised uses of
grouse shooting or deer stalking. Forestry experiences the same climate
and soil limitations as agriculture but in sheltered glens at low
elevation good stands of deciduous trees are possible on deep, free
draining soils. Elsewhere, Scots Pine, Lodgepole Pine and Sitka Spruce are
represented in large-scale plantations which extend upslope to a maximum
elevation of about 500 metres.
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