Precommercial thinning of beech (Fagus sylvatica L.): Early effects of stump height on growth and natural pruning of potential crop trees

• Published in: Scandinavian journal of forest research 2006-10, Vol.21 (5), p.380-387
• Main Authors: Skovsgaard, J.P, Nordfjell, T, Holmgård Sørensen, I.B
• Format: Article
• Language: English
• Subjects: Fagus sylvatica; Forest operations; forest stands; forest thinning; height; intertree competition; mathematical models; natural regeneration; plant competition; regrowth; shoots; stand density; stand management; stump regrowth; stumps; timber management; tree growth; wood quality; Zealand, Sweden
• ISSN: 0282-7581; 1651-1891
• DOI: 10.1080/02827580600979817

This paper reports the early effects of stump height on the growth and natural pruning of potential crop trees after precommercial 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 precommercial 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. Pretreatment stem number (live trees) varied from 17,500 to 41,000 ha −1 . In the potential crop tree treatment, post-treatment stem number ranged from 4750 to 9500 ha −1 . 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.