Abstract

Topping, i.e. cutting or breaking the treetops of secondary stems, may be an attractive alternative to traditional precommercial thinning. The survival and height development of downy birch (Betula pubescens Ehrh.) after topping were examined over three growing seasons in two dense, naturally regenerated stands, 3.1-3.5 m high, in northern Sweden. The topping was performed in experiments with a two-factor randomized complete block design, as follows. Three treatments were applied to individual secondary stems (top-breaking at half the sample tree mean height, top-cutting at half the sample tree mean height, and traditional cutting just above ground) at each of three times: winter, spring and summer (in frozen, dormant and growing conditions, respectively). A control (no treatment) was also included. The survival rate was lowest for traditionally cut stems and for stems cut in growing conditions. Height development after three growing seasons was significantly affected by time of treatment, the height growth being lowest after treatment in growing conditions, but not by treatment. Height growth of control stems was not significantly different from height growth in any combination of treatment and time of treatment, after three growing seasons. However, control stems had the greatest leading shoot length in the third growing season

Keywords

Cleaning; downy birch; height increment; leading shoot length; survival; topping

Published in

Scandinavian Journal of Forest Research
2005, Volume: 20, number: 2, pages: 136-145
Publisher: TAYLOR & FRANCIS AS

SLU Authors

• Karlsson, Anders

  • Department of Silviculture, Swedish University of Agricultural Sciences
    

• Nordfjell, Tomas

  • Department of Silviculture, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Forest Science


Publication identifier

DOI: https://doi.org/10.1080/02827580510008248

Permanent link to this page (URI)

https://res.slu.se/id/publ/6094