Pre-commercial thinning of beech (Fagus sylvatica L.) : early effects of stump height on growth and natural pruning of potential crop trees
Skovsgaard, Jens Peter; Nordfjell, Tomas; Holmgård Sørensen, Ib
This paper reports early effects of stump height on the growth and natural pruning of potential crop trees after pre-commercial thinning of a young stand of naturally regenerated beech (Fagus sylvatica L.) in Denmark. The experiment comprises five treatments based on combinations of three grades of pre-commercial thinning and three stump heights. Treatments include the unthinned control, thinning only of whips and wolf trees (using low stumps), and thinning for potential crop trees using low, medium or high stumps. All treatments were replicated three times. Stump heights averaged 10, 90 or 230 cm, respectively. Pre-treatment stem number (live trees) varied from 17,500 to 41,000 per ha. In the potential crop tree treatment, post-treatment stem number ranged from 4,750 to 9,500 per ha. Following two growth seasons, the quantity of stump regrowth increased with increasing stump height, the rate of stump regrowth increased with increasing stump height, the diameter growth of potential crop trees increased with decreasing stump height, the increase in stand height did not depend on stump height or post-treatment stem number, and the natural pruning of potential crop trees increased with increasing stump height. It remains to be seen, whether these trends hold in the long run, and whether additional economic return from the increase in wood quality with increasing stump height compensates for the reduction in diameter growth.
stand density; stump regrowth; inter-tree competition; forest operations
Scandinavian Journal of Forest Research
2006, number: 21
Publisher: Taylor & Francis
Permanent link to this page (URI)