Growth trends in 10 species of trees in New England, 1950–1980

Tree-ring measurements on increment cores collected from more than 5000 trees during a periodic survey of forest resources in New England indicate trends in regional basal-area increment by species for the period 1950–1980. Two species, red spruce and balsam fir, have had generally decreasing growth rates since the 1960s. Normal aging of the low-elevation, even-aged spruce–fir forest is a probable cause. Eight other species, including sugar maple, had constant or increasing growth throughout the period. White pine had considerably higher growth rates than the other species.