Breeding of Picea mariana (Mill.) B.S.P.: seed orchard and clonal approaches.

Abstract

Black spruce, Picea mariana (Mill.) B.S.P., is one of the most widely distributed species of North American cool-temperate and boreal forests, ranging from the Atlantic Coast in Newfoundland to the Pacific Coast in Alaska. It is relatively resistant to insects and diseases, possesses great reproductive capacity by seed and layering, regenerates well after fire, and is adapted to various soils and local climates. It grows in association with many other species, and pure stands are often found on shallow, poorly drained and cold soils where competitors are lacking. As a result of its favourable wood density and fiber characteristics and the availability of large volumes, it is an important species for the pulp and paper industry. Increased utilization of forest resources in Canada has led to the development of large reforestation programs. Black spruce is the species most frequently planted in Canada east of Manitoba. Significant silvicultural programs for this species also exist in the Lake States of the U.S.A. Along with these programs, selection and breeding were begun in some provinces and states as early as about 1960, first on a small scale, and since about 1975 on a large scale in all areas where the species is important. The purposes of this paper are to review progress in research and breeding during the last 20 years and to propose alternative breeding strategies for advanced generations.(DBO)