Genetic gains from 20 years of cooperative tree improvement in New Brunswick
Bibliographic record
Abstract
The New Brunswick Tree Improvement Council analyzed 20-year data from plantations of unimproved and first generation improved black spruce (Picea mariana [Mill.] BSP) and jack pine (Pinus banksiana Lamb.). STAMAN, a computer model, conservatively projected an 11% merchantable volume gain at 40 years based on 20-year measurements of 36 000 trees. At age 20 years, first generation black spruce was 12% taller and 25–30% greater in total volume. Projections from over 160 000 individual measurements of height from age five to 20 years indicate that by 40 years, gains of 7–8% in height and 18–20% in total volume are likely. Ten year assessments from over 10 000 measurements of second generation black spruce indicate a 30% height gain over first generation material of the same age. For jack pine first generation material, the projections indicated a height gain of 14% and a total volume gain of over 30% at 40 years. Faster growth can provide greater volume at rotation age, a shorter rotation interval, or earlier interventions for commercial thinning. Key words: genetic gain, tree improvement, black spruce, jack pine
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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".