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DYNAMIC STANDARDIZATION OF TREE-RING SERIES
Citation:
Warren, W. AND D. LeBlanc. DYNAMIC STANDARDIZATION OF TREE-RING SERIES. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-94/293.
Description:
The compound growth function of Warren (W.G. Warren, 1980. ree-Ring Bull. 40:35-44) represented an attempt to develop a model-based approach that standardized tree ring width sequences and was more flexible than the monotonic functions that were then commonly used. hile the idea was conceptually attractive, operational difficulties of fitting hindered its use as a practical tool. his paper describes the modifications, and what are believed to be improvements, that have recently been made to the method, and which have led to an interactive computer program by which the fitting of the model to any sequence of ring widths may be readily accomplished. he approach also permits the location of both positive and negative departures from a trend (releases and suppressions, respectively) and estimation of the rate of rung-width increase or decrease. or illustration it has been applied to a sample of red spruce (Picea rubens Sarg.) cores from Whiteface Mountain, New York. ome synchrony in releases and suppressions was detected, with suppressions being very conspicuous since the late 1950s. lso, the recent reductions in growth rates are as great, or greater, than those previously exhibited by the trees of this sample.