ILLUSTRATION OF BIOLOGICAL DRAINAGE IN FORESTED PEATLANDS BY SPATIALLY EXPLICIT SINGLE-TREE GROWTH MODELLING

摘要

Biological drainage describes the possible influence of tree growth on the water-table level in peatlands. This phenomenon is suspected to increase tree growth proportionally to stem density. The height and diameter growth of 240 trees, mainly planted eastern larch (Larix laricina (Du roi) K. Koch) and naturally regenerated black spruce (Picea mariana (Mill.) B.S.P.), have been studied with the help of stem analysis on recently harvested and drained peatland. The growth of each studied tree has been analysed as a function of distance to the closest ditch, basal area within a 3 m radius (G), and competitive rank of the tree compared to its neighbours (G_( > d)/G). Results are showing that tree growth is increasing proportionally to stem density when growth occurs in the same competitive situation and at the same distance from the ditch. Thus, it can be concluded that on recently harvested and drained peatlands, biological drainage promotes growth of individual trees.