Reproductive development and seed ripening in<i>Betula papyrifera</i>along an altitudinal thermal gradient in eastern Appalachia (Canada)
Bibliographic record
Abstract
In several gymnosperm tree species of the circumboreal forest, reproductive development is closely associated with the accumulation of degree-days during the growing season. We wanted to verify whether this pattern holds for a widespread angiosperm species such as paper birch ( Betula papyrifera Marsh), a broadleaf tree distributed throughout the North American boreal forest. Stations to simultaneously measure the thermal sum (degree-days > 5 °C, DD) and the reproductive development (anatomical development and seed germination) were installed in four sites along an altitudinal thermal gradient totalling 541 m a.s.l. in the eastern Appalachian Mountains (Canada). In 2004, sites 1, 2, 3 and 4, received 973, 1099, 1266 and 1359 DD, respectively. A strong relationship was found between thermal sum and reproductive development (anatomical development: r2 > 0.90; seed germination r2 > 0.72). This relationship seems to be based on the absolute value of heat-sum received because (i) rates of reproductive development are twice as high in colder sites (1 and 2) than in warmer sites (3 and 4), and (ii) total seed germination did not differ among the sites. Along with this, we noted a lesser production of full seeds in colder sites, coupled with a higher success of germination in the coldest site (site 1), which appears to be a mechanism of phenotypic adaptation to cold.
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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) | 0.000 | 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".