A regional sample of tree-ring measurements was used to determine average annual growth in trees of 10 major species in New England. There have been extended periods of decreasing growth rates in red spruce since about 1960 and in balsam fir since about 1965. The other eight species, which included sugar maple and white pine, showed constant or increasing growth rates through 1980. The decreases in growth rate in sampled red spruce and balsam fir were independent of physical site characteristics, elevation, and geographic location, indicating that regional factors are involved. Weather parameters and indexes were not closely correlated with growth rates, and the best predictive equation explained only 33 percent of annual variation. Due to past harvests and epidemics of the spruce budworm, much of the red spruce-balsam fir forest below 1,000 m in elevation can be considered to be functioning as even-aged. Historical growth information suggests that these trees should have reached maximum growth around 1960, and that decreasing growth rates since then are the result of normal aging.

Harold Burkhart and Bronson Bullock have updated the quintessential introduction to forest measurements, providing a new generation of forestry students at all levels with the concepts and methods they need for career success. With attention to detail and clear, precise language, the authors present timber measurement techniques applicable to any tree inventory regardless of management objectives. Assuming no more mathematical background than algebra and plane trigonometry, the authors begin with basic statistical concepts to ensure that even introductory students benefit from the book’s concise explanations. Comprehensive coverage of sampling designs, land measurements, tree measurements, forest inventory field methods, and growth projections assures utility for foresters throughout their education and beyond. The new edition includes expanded discussions of information technology and geospatial information systems commonly employed in assessing forest resources. Recognizing the needs of contemporary forest inventories and models, a new chapter on assessing forest carbon builds on the foundations of traditional forest measurements, sampling, and modeling. Abundant photographs and illustrations highlight and clarify important concepts, while many numerical examples allow readers to become comfortable with the quantitative tools employed by foresters.