STUMP HEIGHT EFFECTS ON SPROUTING OF MOUNTAIN MAPLE, PAPER BIRCH AND PIN CHERRY - 10-YEAR RESULTS

Stump sprouting of mountain maple, paper birch and pin cherry was stud ied in relation to residual stump height. The three-year-old stems wer e cut at stump heights of 0, 15, 45 and 75 cm in a completely randomiz ed plot design. Two growing seasons after cutting, the percent of stum ps with live sprouts was lower for the low stump heights, Two years af ter cutting, the mean number of sprouts per stump of the three species significantly increased with stump height but the effect was no more significant after IO years. Initially, total height of the sprouts was significantly greater for the higher stump heights of the three speci es, which is explained by the point of origin of the sprouts along the stump. After 10 years, this effect was no more significant. Except fo r pin cherry after the first growing season, the three species produce d sprouts of similar vigor during the first 10 years, expressed in ter ms of both diameter and height growth, among the four stump heights, I n view of the increasing stump mortality of these three species after manual or mechanical release treatments of a conifer regeneration, a c ut height of 15 cm is recommended. Conversely, increasing stump height will likely favor sprout production, which could be advantageous in w ildlife habitat management for browse consumption.