High altitude colonisation of the Northern Corries of Cairn Gorm by Scots pine (Pinus sylvestris)

Abstract

Colonization by Scots pine of ground up to 850 m in the Northern Corries of Cairn Gorm has been taking place for about 40 years, since the fencing of lower ground for commercial forestry and reductions in grazing pressure from red deer. Sapling densities were monitored in 1984 and 1994 along fixed transects. The highest densities were generally in the western corries of the series, but there were also substantial numbers in the ski area and in the eastern corries. The highest densities above 650 m were in the ski area. There were more saplings on ridges than in corries, and fewer than expected in mire vegetation. Densities increased between 1984 and 1994, with a higher proportion of seedlings to saplings at the second analysis. The age structure showed a slow progression towards that recorded for the natural tree‐line at Creag Fhiaclach. Outside the part of the area designated as a Site of Special Scientific Interest it might be possible to speed up the progression by additional planting or other measures.

Key words:

• Cairngorms
• Colonisation
• Monitoring
• Scots pine
• Tree‐lines