© 1979 by Institute of Chartered Foresters
The Effects on Song-Bird Populations of Upland Afforestation with Spruce


Department of Forestry and Natural Resources, University of Edinburgh The Kings Buildings, Mayfield Road, Edinburgh EH9 3JU.
- Large coniferous plantations have been established widely in uplands previously used for rearing sheep and cattle, causing fundamental changes in the wild life of these areas.
- Breeding song-birds were censused in south-west Scotland on upland moorland grazed by sheep and in spruce plantations at different stages of growth.
- The commonest song-bird species were meadow pipit and skylark on unplanted areas, meadow pipit in establishment plantation, willow warbler and wren in thicket, and goldcrest, chaffinch and wren in polestage and thinned plantations.
- Total song-bird densities were 4070 pairs km2 on unplanted heather, 70130 pairs km2 on unplanted grass, 125200 pairs km2 on 6 year old trees, 230290 pairs km2 on 1214 year old trees, and 300440 pairs km2 on trees over 20 years old. Bird species diversity was also greatest in trees over 20 years old, with one exception.
- Many bird species depend on unafforested moorland, but were not censused since they are too sparsely distributed. Their loss is to be set against the gain in numbers of smaller song birds following afforestation which was inferred from the study plots. From the standpoint of bird conservation, diverse forest structure and the retention of some large unafforested upland areas is advocated.