Some climatic aspects of biomass productivity of white spruce stem wood
Biomass productivity was determined for white spruce (Piceaglauca (Moench) Voss) in the boreal forests of Alberta, the Northwest Territories, and Manitoba. Comparisons were made between southern and northern locations, between eastern and western transect locations, and between older (200 + years) and younger (110 years) trees. At 13 sampling locations, X-ray densitometric tree ring data were obtained from the base of the stem, breast height, and from five points equidistant along the stem. Markedly higher stem wood biomass productivity was found for the 110-year-old trees than for the 210-year-old trees in Alberta; average ring weights were 3.8 and 1.2 g for the first 100 years of growth in 1 cm thick disks at breast height. These results suggest that climatic warming since the end of the Little Ice Age (ca. 1850) has resulted in higher biomass productivity in the Canadian boreal forest.