Vegetative Propagation of Conifers as a means of Intensifying Wood Production In Britain*

Estimates suggest that intensified silviculture using improved genotypes could raise productivity of existing forests in Britain by 30 per cent, thus reducing reliance upon imported timber. This increase is most readily attainable in upland coniferous forests where Sitka spruce is the major species. Superior families of Sitka spruce can now be identified with a ten per cent increase in vigour over ordinary seed lots. However, supplies of improved seed will not be available in significant quantities until after 2000. Research into vegetative propagation was begun to speed the introduction of improved material into commerce. Early work on the propagation of superior clones failed because of problems of maturation. Subsequent investigation has concentrated upon propagation of young individuals of improved genotypes grown from seed produced by artificial pollination of tested clones. Techniques for large-scale production of rooted cuttings of these improved genotypes have now been successfully developed. Following favourable financial appraisals, commercial trials of the system are under way. Based on experience with Sitka spruce, three preconditions are proposed for large-scale propagation programmes. These are use of cuttings from young parents, propagation of proven superior genotypes, and use of the technique with material in short supply. The possible role of vegetative propagation for other commercially important conifers is discussed with only Hybrid larch considered promising. Some implications for broadleaves and the potential role of tissue culture are mentioned