Influence of White Pine on Structure and Yields of Mixed Northern Conifer Forests

Abstract

The presence of white pine (Pinus strobusL.). influenced the structure and yields of mixed-species, multi-cohort, northern conifer stands in Maine. In each of the five stands studied, mean plot volumes were consistently higher where white pine grew with more shade tolerant conifers, than in plots without the additional pine component. However, considerable variability in stand structures among plots resulted in no significant differences in volumes within stands. When plot volumes from the five stands were combined, the larger sample size resulted in the mean volume of pine plots being significantly higher (P < 0.02) than those that had none (355.30 ± 25.24 m3/ha vs. 275.06 ±16.98 m-Vha). Generally, pine's presence enhanced plot volumes but had a negative effect on spruce and hemlock volumes. Whether or not pine was present, plot volumes were greatly affected by variability in age structures. Plots with a representation of two or three cohorts had higher volumes than plots with a single cohort.