Transformation from even-aged plantations to an irregular forest: the world's longest running trial area at Glentress, Scotland
Authors: Kerr, Gary; Morgan, Geoff; Blyth, John; Stokes, Victoria
Source: Forestry, Volume 83, Number 3, July 2010 , pp. 329-344(16)
Publisher: Oxford University Press
Abstract:The main aim of the Glentress Trial Area has been to study the transformation of even-aged plantations to a permanently irregular structure using group selection. The Trial Area was established in 1952 when most of the plantations were 2030 years old. The 117-ha area was divided into six Blocks and the plan was to transform the area over a 60-year period by felling and regenerating groups totalling 2 ha in each Block every 6 years. The objectives of this paper are (1) to examine the design, implementation and monitoring of the process of transformation and (2) to investigate if the data collected can be used to quantify the progress of transformation to an irregular structure. The Trial Area has been driven by a clear objective but unfortunately the management plan has not been revised and there has not been a consistent approach to record keeping. This has made it difficult to relate management interventions to the development of the forest structure. An earlier analysis claimed that transformation was almost complete; this was based on a comparison of diameter distributions of the 1990 data with an exponential regression. However, the analysis in this paper includes all the data collected between 1952 and 1990 and shows that the diameter distribution of all Blocks has been similar to an exponential since the start of the Trial. The main reason for this is that the monitoring unit has been the Block, and a spatial scale of 20 hectares is probably too coarse to detect the changes that are clear in aerial photographs.
Document Type: Research article
Publication date: 2010-07-01
- Forestry publishes refereed papers on all aspects of research, practice and policy that promote the sustainable development of forests, woodlands and trees. In considering suitability for publication attention is given to both the originality of contributions and their practical application. Preference is usually given to work undertaken in the temperate and/or boreal zones; only articles of exceptional merit from tropical zones will also be considered.