Dendroecological Studies in the Front Range, Colorado, U.S.A.

Abstract

Two dendroecological procedures are described. The first involves the radiodensitometric analysis of conifer material from an altitudinal transect between the subalpine and the lower, and timberline. Core samples were taken from selected stands with very differing site conditions at three altitudes, and tree-ring parameters including maximum latewood density, latewood width, and total width were measured. A special type of diagram was developed to assist analysis of the complex relationships between tree-ring growth, weather, and site conditions on a year-for-year basis. This is a departure from the conventional approach of analyzing only mean relationships over long time sequences. An advantage of the elaborated single-year method is that the growth models are allowed to vary with time. Typical cases are illustrated, and the dynamics of the overlapping influences of weather and site conditions are discussed. The second procedure comprises the visual identification and dating of abrupt, persistent changes in the tree-ring pattern and their relation to biotic and abiotic factors. This allows the reconstruction of insect attacks, forest fires, and forest clearing.