Crowns Of Mature Trees Research Articles

Tree shoot elongation in northern Wisconsin and relationships with temperature and precipitation

The relative amount of shoot elongation in the upper crowns of mature trees was studied in a forest community near Rhinelander, Wisconsin. Curves of the percentage of total elongation for the 1970 through 1973 growing seasons were similar to those previously reported for younger trees, but the elongation periods were generally shorter. Quercusrubra had the shortest period of elongation, followed by Acersaccharum. Tiliaamericana, Acerrubrum, Betulapapyrifera, Populustremuloides, and Abiesbalsamea in order of increasing duration. Comparisons were also made of the elongation patterns among species and years. Expected dates for the attainment of 10% elongation based on heat sums and year-day were compared with the observed dates. For all species except A. balsamea and A. saccharum, the comparison demonstrated the use of heat sums in predicting initial elongation.