Die Birke - Standortansprüche und Möglichkeiten der züchterischen Verbesserung

1998

S. 99-104

33 Lit. Ang.

Unselbständiges Werk

200100762

The indigenous birches of Germany, Betula pendula and Betula pubescens, are shortly described regarding ecological and silvicultural situation, propagation strategy, damages, wood, and hybridization. Both birches have their optimum on well drained, fertile sites. Due to competition they have their ecological niches however on wet and dry sites. The production of valuable timber, which may reach prices of mire than DM 1000,-/mß, is possible on more fertile sites in mixed hardwood or coniferous stands. Another option is the plantation of selected birch on abandoned farmlands as a pioneer stand with production purpose and for the protection of more sensitive species. Breeding work with birch includes testing and selection of species, provenance selection, plus tree selection with seed orchard establishment and controlled hybridization including species hybridization. Besides the two native species the exotics Betula maximovicziana, Betula papyrifera, Betula populifolia and Betula aschersonicea seem to be of onterest. From the native species Betula pubescens is faster growing with better form. Provenances from northern Germany and The Netherlands are fast growing with good shape. Polish provenances show average performance with a wide range of variation, and provenances from Finland and Sweden are slowly growing under German conditions. The best growth and form was found in Betula pubescens seed orchard progenies. Hybrids between Betula platyphylia japonica and Betula pendula may outgrow Betula pendula by 100% in volume production. Flower induction and vegetative propagation by tissue culture and cuttings is easily possible, which allows rapid mass propagation of valuable selected material.