Low soil temperature inhibits the stimulatory effect of elevated [CO <sub>2</sub> ] on height and biomass accumulation of white birch seedlings grown under three non‐limiting phosphorus conditions
Bibliographic record
Abstract
White birch ( Betula papyrifera Marsh.) seedlings were exposed to ambient or doubled ambient carbon dioxide concentration ([CO 2 ]), three soil temperatures ( T soil ) (low, intermediate, high), and three phosphorus (P) regimes (low, medium, high) in environment‐controlled greenhouses. Height ( H ), root‐collar diameter (RCD), biomass, and leaf phosphorus concentration (leaf P) were determined four months after initiation of treatments. The low T soil reduced H , RCD, shoot biomass, root biomass and total seedling biomass whereas the high‐P level and the [CO 2 ] elevation increased all the growth and biomass parameters. Elevated [CO 2 ] significantly reduced leaf P. There were significant two‐factor interactions suggesting that the effect of elevated [CO 2 ] on (1) H , total biomass, biomass of plant components, and leaf P was dependent on T soil , (2) total biomass was contingent on P regime. For instance, the positive response of H and total biomass to elevated [CO 2 ] was limited to seedlings raised under the intermediate and high T soil , respectively. In addition, [CO 2 ] elevation increased total biomass only at the high‐P regime but not at the low‐ or medium‐P level where the effect of [CO 2 ] was statistically insignificant. No significant main effect of treatment or interaction was observed for root to shoot biomass ratio.
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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 | 0.001 |
| 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".