Information and Advsiory Note Number 75, January 1997
1.1 National Countryside Monitoring Scheme (NCMS) results now describe Scottish land cover for the 1970s and the I 980s. These are extrapolated from a stratified random sample which covers 7.5% of the land area of Scotland. Land cover information relating to 31 area and 5 linear features was derived from aerial photographs and mapped at 1:10,000 scale. The maps were digitised and entered into a Geographic Information System (GIS) in which the data were processed and classified. Statistical programs calculated estimates of areas and lengths, together with change within and interchange between feature types. Accompanying all results are confidence intervals which indicate the precision of estimates. The project was designed to identify changes of 10% or more in spatial or linear extent with 95% confidence.
1.2 Summary results for Scotland are shown in Table 1
2.1 Grassland was the largest land cover group, covering approximately 28% of the country. About half was unimproved grassland. There was little, if any, change in the area of unimproved or semi-improved grassland. Improved grassland was reduced by 15%, mostly to arable.
2.2 Mire was the second most extensive group. This was interpreted into upland categories of heather and sedge dominated blanket bog and the less common lowland mire. All were reduced in area; heather dominated mire by 21%, sedge dominated mire by 9% and lowland mire by 23%. As a group mire was reduced by 16% of its 1970s area.
2.3 Heather moorland covered 15% of Scotland in the 1970s and remained little changed.
2.4 The arable area increased by 15%, mostly from improved grassland.
2.5 In the woodland and scrub group, semi-natural broadleaved woodland was reduced by 10%. 32% of mixed woodland was lost, mostly to other woodland categories. Tall scrub increased by 9%. Coniferous and young plantation increased by 58% and 53% respectively.
2.6 In the water group there was a 2% loss of lochs and a 12% increase in reservoirs, associated with hydroelectric development in upland Scotland.
2.7 Built land increased by 8% and transport corridors (roads and railways) by 10%.
2.8 Notable changes among the ‘other’ features included increases of 213% in bare ground, 63% in bracken, 29% in wet ground, 29% in quarries and 20% in recreational land.
2.9 Linear features show a 23% reduction in the length of hedgerows but a 10% increase in the length of lines of trees. The length of ditches increased by 59%. Unsurfaced tracks increased by 5%.
3.1 Figure 1 (page 5) illustrates the major interchanges (>0.5% of Scotland's area) between land cover features for the 1970s-1980s.
3.2 In the lower right part of the diagram, arable - grass rotation, as part of the agricultural cycle, results in a large interchange and a net gain from grassland to arable.
3.3 Within the grassland group interchanges occurred among the three types, with a general trend towards grassland improvement.
3.4 Large interchanges between heather moorland and unimproved grassland took place, with a net loss of heather moorland. Causes may be associated with changes in land management, notably muirbum (the burning of heather to provide fresh grazing for deer and grouse) and shifts in the intensity of hill grazing.
3.5 Conversion of blanket mire to unimproved grassland and heather moorland occurs when bog is drained and prepared for commercial forestry. The drainage of mire, as well as the afforestation of mire, heather moorland and unimproved grassland is shown in the upper part of Figure 1. This also shows that, while heather moorland remained largely unchanged in area from the 1970s to the I 980s, losses did occur from conversion to grassland and planting to forestry. These were compensated for by mire drainage.
3.6 Conversion of unimproved grassland to bracken occurred.
3.7 The general trend has been a reduction of semi-natural features. Blanket mire, heather moorland and unimproved grassland were lost to plantation forestry, and there was a shift within the grassland group towards grassland improvement.
4.1 NCMS results are also produced for each of the 12 former Scottish administrative regions (as portrayed by the Ordnance Survey Local Government Areas map of 1984).
4.2 Areas which retained a high proportion of semi-natural land cover and which experienced relatively little change include the Western Isles and Shetland, and to a lesser extent Highland. These areas were characterised mostly by upland areas of blanket bog, heather moorland and grassland communities.
4.3 Regions with substantial semi-natural cover but higher rates of change include:
Borders, Dumfries and Galloway, Grampian, Central, Tayside and Strathclyde. In these areas, semi-natural land cover in the uplands gave way to afforestation. In the lowlands, agricultural intensification took place with grassland improvement and an increase in arable.
4.4 Regions with relatively little semi-natural cover and low levels of change are Orkney, Fife and Lothian.
5.1 Results for the 1970s-1980s comparison confirm the trend established by the 1940s-1970s results i.e. that semi-natural features decreased. In the 1970s, 53,339 sq. kin, or two thirds of Scotland could be classed as ‘semi-natural’. By the 1980s the semi-natural land had decreased to 49,886 sq. km.
Mackey, E.G. and Tudor, G.J. (in press). Land cover changes in Scotland over the past 50 years. In Vegetation Mapping: from Patch to Planet, (Ed. R. Alexander), John Wiley & Sons.
NCMS reports describing 1940s-1970s results for the following Regions can be obtained from SNH Publications Section, Battleby: Grampian, Borders, Lothian, Dumfries & Galloway, Northern Isles, Central, Fife, Tayside, Highland, Strathclyde and the Western Isles.
Tudor, G.J., Mackey, E.C. and Underwood, F.M. (1994). The National Countryside Monitoring Scheme, the changing face of Scotland 1940s to 1970s. Main report. Scottish Natural Heritage, Perth.
Tudor, G.J. and Mackey, E.G. (1995). Upland land cover Change in post-war Scotland. In Heaths and Moorland: Cultural Landscapes. (Eds. D.B.A. Thompson, A.J. Hester and M. B. Usher). HMSO, Edinburgh.
Dr Gavin Tudor
National Countryside Monitoring Scheme -
Scottish Natural Heritage
2 Anderson Place
EDINBURGH EH6 5NP