Individual study: The creation of structural diversity and deadwood habitat by ring-barking in a Scots pine Pinus sylvestris plantation in the Cairngorms, UK
Agnew J.M. & Rao S. (2014) The creation of structural diversity and deadwood habitat by ring-barking in a Scots pine Pinus sylvestris plantation in the Cairngorms, UK. Conservation Evidence, 11, 43-47
Fifteen-hundred Scots pine trees were ring-barked (as individuals, groups of five or 15) on Mar Lodge Estate, Scotland in order to create structural diversity and deadwood habitat in two plantations. A sample of 220 was monitored annually and compared with a control sample of 10 non ring-barked trees, to quantify structural changes as well as use by saproxylic invertebrates and woodpeckers. Eight years after ring-barking 26.1% (±6.13% S.E.) of the trees had snapped off and 2.4% (±1.37%) had fallen over completely; 48.0% (±12.5%) had lost 60-90% of their branches and 34.9% (±24.2%) had lost more than 50% of their bark. Additionally 98.5% (±0.92%) of the trees showed signs of wood boring invertebrates and 74.5% (±11.6%) were used by woodpeckers. Six species of beetle, four of which were saproxylic, and a single species of saproxylic fly were identified from fallen deadwood from the ring-barked trees. The control trees remained largely structurally unchanged and none were colonised by saproxylic invertebrates or woodpeckers. There were significant differences in structural change and use by woodpeckers between the two plantations but none in the occurrence of saproxylic invertebrates. Group size had no significant effect on colonisation, except for woodpeckers which used small groups of trees significantly more than larger groups. Ring-barking can provide an effective management tool to create structural diversity and deadwood habitat within a short period of time. However it is necessary to regularly repeat ring-barking in groups of different size in order to maximise structural variation and ensure niche diversity of such a dynamic substrate.