White spruce growth to age 44 in a provenance test at the Petawawa Research Forest
Bibliographic record
Abstract
Twenty-five provenances of white spruce were planted in 1963 in 144-tree plots and three replications as part of a provenance test series for eastern Canada. The experiment was well maintained and thinned to 50% of its original stocking in 1986 (age 26 years from seed).Measurements at age 44 were subjected to analyses of variance and correlation and compared with height and survival at age 15. The results demonstrated that at age 15, identification of the best provenances is ineffective because of changes in rank and the late expression of survival differences. At age 44, significant differences among provenances were observed for survival, mean height, diameter, basal area, and volume. The greatest volume was produced by a provenance from Cushing in the Ottawa Valley in Quebec, 287 m 3 per ha, which was 11% greater than the volume of the local provenance, Chalk River, Ontario. When ranked on the basis of survival and volume, the best eight provenances included five from Quebec, and one each from New Brunswick, Ontario, and Wisconsin. The experiment shows that at the appropriate stage in a selection program, large plots can yield significant results, which has important implications for the design of experiments. Key words: provenance tests, jack pine, experimental design, growth and yield
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".