Some effects of the first rotation on site properties.

  • D.C. Malcolm Dept. of Forestry and Natural Resources, University of Edinburgh.
Keywords: British Isles, afforestation, soil, climate, mineralogy.


The greater proportion of the land under forest plantations in the British Isles was not carrying forest when these stands were established. Most of this land had not been tree-covered for long periods before afforestation. During the treeless period changes in soil development took place primarily owing to the climatic changes which led to our present oceanic climate, characterised by strong winds, moderate to heavy precipitation and the generally low potential evaporation of the cool summers in the west and uplands. The influence of this cool humid climate on soil development obviously varied with combinations of topography, aspect and lithology, the last being the predominant factor as it influenced both the mineralogical and physical status of the profile. On many lithologies the inheritance of glaciation was a deep layer of till of low permeability (e.g. on Carboniferous rocks) sometimes with indurated layers (e.g. on Devonian rocks) which limited the capacity of the profile to absorb and conduct water. The resulting seasonal anaerobic conditions, cool climate and poor mineralogy led to accumulation of organic debris on the surface. The result of these conditions, no doubt assisted by centuries of grazing, muirburn and extensive use, was the development of the site characterised by poor internal drainage. The important soil types are peaty ironpans, surface water and peaty gleys and peats of varying depths and kinds (Pyatt 1970). During the 19th century these soils, which now account for more than three quarters of the afforested land in Britain (Pyatt 1979), were considered unplantable. With the gradual development of afforestation techniques from the introduction of the planting turf to the intensive mechanised drainage and cultivation of today, these apparently intractable sites have become available to forestry.
How to Cite
Malcolm, D. (1979) “Some effects of the first rotation on site properties.”, Irish Forestry. Available at: (Accessed: 30September2023).