E.P. 511 - Crop-tree thinning of western larch

Objectives:

• To determine the response to spacing of older western larch trees. This trial was established in 1958 in a fire-origin, 31-year-old, mixed stand of western larch, Douglas-fir and lodgepole pine, on an IDFdm2 site northwest of Cranbrook in the Cranbrook Forest District. In this single-tree experiment, 120 larch trees were selected, with 20 trees in each of six diameter classes. Four crop-tree thinning treatments (clearance of all competing vegetation to radii of 2.4, 3.6 and 4.8 m around each tree, and no clearing) were randomly assigned to five trees in each diameter class. The trees have been remeasured on roughly a five-year schedule for the life of the trial.

Publications:

• Crop-tree thinning of western larch in southeastern British Columbia: 30-year results.