Precommercial thinning of trembling aspen in northern Ontario: Part 1 – Growth responses
Bibliographic record
Abstract
In Ontario, trembling aspen (Populus tremuloides Michx.) utilization has increased over the past 20 years and this trend is expected to continue. With this increased demand, questions are being raised about stand conditions required for optimum growth. In 1979, a study was initiated across the commercial range of aspen in northern Ontario to determine the optimum precommercial thinning intensities for aspen tree and stand growth. Six pure aspen stands between the ages of five and 22 years were thinned to residual spacings of 2 × 2 m, 3 × 3 m, 4 × 4 m, and 5 × 5 m. Unthinned and thinned plots were measured at regular intervals for up to 17 years after treatment. Diameter increased significantly with residual tree spacing over the range of site conditions, geographic locations, and tree ages. Precommercial thinning resulted in significantly increased height in three of the stands, and height generally increased with increased residual spacing. Fifteen to 17 years after treatment, gross total volume (GTV) was highest in the unthinned plots for all six stands and decreased as residual tree spacing increased. Gross merchantable volume (GMV) did not vary significantly with thinning in all but the oldest stand. The results of this study do not support the use of precommercial thinning to increase aspen fibre yield. However, if the management goal is maximizing individual tree growth, precommercial thinning of aspen should be considered. Key words: Trembling aspen, precommercial thinning, DBH response, height response, northern Ontario
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".