- Department of Energy and Technology, Swedish University of Agricultural Sciences
Johansson, Tord; Lundh, Jan-Erik
Root cuttings from 10-year-old European aspen (Populus tremula L.) were rooted in decomposed Sphagnum peat and sand. The root cuttings were exposed to different temperatures (10 and 25 degrees C) and a light intensity of 300 mu mol m(-2) s(-1) for 83 days. Five levels of root depth were used: 2, 4, 6, 8 and 16 cm. Suckers of another clone of 15-year-old European aspen were exposed to different light intensities (300, 150, 75 and 30 mu mol m(-2) s(-1)) for 120 days. The percentage of sprouting aspen cuttings was highest in the upper part of the peat (2-6 cm). The total number of suckers was highest at 4 and 6 cm root depths. Dry weights of suckers at 4 and 6 cm root depths were 4 200 and 3 840 mg at 25 degrees C and 340 and 180 mg at 10 degrees C, respectively, but were negligible at other root depths. Cuttings produced more suckers when exposed to 25 degrees C than to 10 degrees C. Most of the suckers were produced during 15-25 days after planting. Dry weights of suckers exposed to 300, 150, 75 and 30 mu mol m(-2) s(-3) were 1831, 2280, 1107 and 323 mg, respectively. A practical implication of the relation between temperature level and sucker production and height is avoiding large openings in stands where aspens have been cut. When preventing aspen suckers the aspen ought to be cut in young dense thinning stands where temperature and light intensity are lower than on open areas such as clear cuts.
Populus tremula L.; European aspen; light intensity; temperature; root depth; root suckers; cuttings
Scandinavian Journal of Forest Research
1988, Volume: 3, number: 1-4, pages: 75-82