Practical demonstration of thinning and pruning on a farm woodlot (EP 499)

Objectives

To demonstrate desirable forest practices.

Treatments

The experiment was established at Comox in 1954 in a fairly uniform naturally-regenerated stand consisting mainly of Douglas fir at age 45 years. An area of about 20 acres was divided into 18 rectangles in which one of 3 treatments were applied: thinning and pruning; thinning and no pruning; and untreated control. A permanent 0.04 ha circular sample plot was established within each replicate in which tree measurements were taken. Thinned removed large, heavily limbed trees with a d/D ratio of 0.98 and a residual basal area of 130 ft²/acre (29.8 m²/ha) and 120 ft²/acre (27.5 m²/ha) on the thinned and thinned and pruned plots respectively. After thinning, all suitable trees within the treatment area were pruned to a height of 18ft (5.5m). In 1962 the stand was measured and marked for thinning but a timber sale attracted no bids and the plots were left dormant until 1980.

Status

Final measurement taken in 1988, released in 2001.