• Safford, Lawrence O.
  University of Maine Graduate School
  

Forest managers are interested in knowing the productive capacity of the lands under their management. They use an index of potential production based on height growth of selected individuals in the stand to make relative comparisons among stands. With tolerant species and unmanaged stands of mixed composition such as those found in the spruce-fir region of Maine, even the conventional method of comparing productivity become difficult to use.

A study was designed with the objective of measuring and comparing several growth functions of 10 selected free growing dominant red spruce (Picea rubens Sarg.) from each of 10 sites representing widely differing soil properties as methods of estimating differences in potential productivity among the sites. detailed stem analysis of each tree gave a record of the height, diameter and volume growth patterns over the entire life of the trees. Individual tree curves of height, volume, and basal area over age were polymorphic, although most curves for a site tended to follow the same general pattern. Attack by the spruce budworm during the late 1920's influenced the growth curves of some of the trees.