Comparison of crown density assessments on trees within the stand and on ride edges within the forest

摘要

Assessments of tree health using scoring systems based on the visual appearance of the tree crown are used throughout Europe. The principal parameter assessed is the amount of defoliation in the sample tree when compared to a healthy tree of the same species. Different methods are used to select sample trees. This study compares the results of 2 years of assessment on matched pairs of plots in oak (Quercus robur and Q. petraea) and Scots pine (Pinus sylvestris L.), where assessments of crown condition of trees selected from the edge of a stand were compared with trees selected from within the stand. Trained forest surveyors carried out the assessments as part of the UK's national annual tree health survey and the same methods were used. Results showed there were no significant differences in any of the parameters assessed between trees within the forest stand and those on the edge of a forest road or ride. This suggests that the practice of selecting sample trees from ride or road edge trees within a forested area does not affect the health scores for trees in Britain.