Abstract

Plantings with pendula (Betula pendula Roth) and pubescent (Betula pubescens Ehrh.) birches were studied on five localities (Lat. 57-60 N) in Sweden. The birches were planted in 1988 or 1989. The experiment contained 50 plants per parcel and five replications per treatment. Among treatments harrowed area and birches covered with tree shelter were included. In spring 1993 five plants growing on harrowed area, with and without tree shelter respectively were randomly chosen on a parcel. Totally 25 birches per treatment, species and locality was used. The trial was replicated in 1994 and 1995. The plant height was estimated and diameter at 20 and 60% of tree height was measured each year for 4 years. The stem taper was calculated by the quotient D60/D20. The stem taper for birches without tree shelter was 0.5 for both species on all localities. The quotients for birches, which have grown in tree shelter, were 0.6-0.75 the first years of the trial. Then the quotients decreased and 2-3 years later they were on the same level as for birches planted without tree shelters. Resulting of the studies indicate that tree shelters should be removed two to three years after the plant has reached the top of the shelter. The height of the tree shelter might be shortened to 0.8-1.0 m to stabilise the plant earlier than with the conventional shelter height of 1.2 m

Keywords

Betula pendula; Betula pubescens; Pendula birch; pubescent birch; stem taper; tree shelter

Published in

New Forests
2004, Volume: 27, number: 1, pages: 13-24
Publisher: KLUWER ACADEMIC PUBL

SLU Authors

• Johansson, Tord

  • Department of Energy and Technology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Forest Science


Publication identifier

DOI: https://doi.org/10.1023/A:1025021926765

Permanent link to this page (URI)

https://res.slu.se/id/publ/8643