<P> The oldest forests in the northwest boreal region, some older than 300 years, are of white spruce occurring as pure stands on moist floodplains (Rowe 1970). Here, the frequency of fire is much less than on adjacent uplands dominated by pine, black spruce and aspen . In contrast, in the Cordilleran region, fire is most frequent in the valley bottoms, decreasing upward, as shown by a mosaic of young pioneer pine and broadleaf stands below, and older spruce--fir on the slopes above (Rowe and Scotter 1973). Without fire, the boreal forest would become more and more homogeneous, with the long - lived white spruce gradually replacing pine, aspen, balsam poplar, and birch, and perhaps even black spruce, except on the peatlands (Raup and Denny 1950). </P> <P> Large areas of Siberia's taiga have been harvested for lumber since the collapse of the Soviet Union . Previously, the forest was protected by the restrictions of the Soviet Forest Ministry, but with the collapse of the Union, the restrictions regarding trade with Western nations have vanished . Trees are easy to harvest and sell well, so loggers have begun harvesting Russian taiga evergreen trees for sale to nations previously forbidden by Soviet law . </P> <P> In Canada, eight percent of the taiga is protected from development, the provincial government allows forest management to occur on Crown land under rigorous constraints . </P> <P> The main forestry practice in the boreal forest of Canada is clearcutting, which involves cutting down most of the trees in a given area, then replanting the forest as a monocrop (one species of tree) the following season . </P>

What is the climate like in a taiga biome