Variation in biomass production, moisture content, and specific gravity in some North American willows (Salix L.).

Biomass production and quality in seedlings and coppices of Salixamygdaloides Anderss., S. eriocephala Michx., S. exigua Nutt., and S. lucida Muhl. were investigated in a full-sib family test. Between 65 and 77% of the variation in plant biomass was due to species, while less than 5% was due to families. Approximately 39% of the variation in moisture content and 37% of the variation in specific gravity was due to species differences, while only 3 and 14%, respectively, was due to families. Salixeriocephala produced the highest yields, with an average 1-year coppice production of almost 1 kg/plant (dry matter) and had the lowest moisture content and highest specific gravity of the four species. There was a strong positive correlation between seedling and coppice productivity for all species, with S. eriocephala and S. lucida producing the most vigorous regrowth from coppice.