SYNCHRONIC LARGE-SCALE DISTURBANCES AND RED SPRUCE GROWTH DECLINE

Tree-ring data from the USDA Forest Service Forest Inventory & Analysi s and other independent sources were used to study coincidence of chan ges in growth and large-scale disturbances. Numerous studies report th at mean radial growth of red spruce (Picea rubens Sarg.) declined sync hronously throughout its range in the early 1960s. We use red spruce t ree-ring data from most of the major studies to show that the synchron icity of red spruce growth decline is likely the outcome of the large- scale disturbances that occurred throughout the northeastern red spruc e ecosystem in the late 1930s to early 1950s. Large-scale disturbances are either not detectable or not present in the same time interval in the southern Appalachians. This appears to correspond to an absence o f a 1960s radial growth reduction in this region.