Natural Development of Stand Struc- ture in Peatland Scots Pine Following Drainage: Results Based on Long-Term Monitoring of Permanent Sample Plots

land Scots pine following drainage: results based on long-term monitoring of permanent sample plots. Silva Fennica 38(4): 405–412. We studied the dynamics of stand structure on drained peatland sites in Scots pine domi-nated stands untreated with thinnings. The data consisted of consecutive stand measure-ments in 10 permanent sample plots where the monitoring periods varied from 29 to 66 years. We assumed that the stand’s structural development was driven by the natural processes of regeneration, growth, and mortality, all related to inter-tree competition within the stand. The DBH distributions of live and dead trees at different times of post-drainage stand development – smoothed by Weibull function – were analysed to characterise the change in stand structure. The initial uneven-sized structure of the natural, widely-spaced stands became more uneven during the first decades following drainage due to enhanced regeneration. Later, as stand density and mean tree size continuously increased, the DBH distributions approached bell-shaped distributions. Accordingly, the suppressed trees showed their highest mortality rate during the first decades, but the peak of the mortality distribution shifted to larger trees along stand succession. The change in structure wa