Canopy carbon and oxygen isotope composition of 9-year-old hoop pine families in relation to seedling carbon isotope composition, growth, field growth performance, and canopy nitrogen concentration
Bibliographic record
Abstract
Carbon isotope composition (δ13C), oxygen isotope composition (δ18O), and nitrogen concentration (Nmass) of branchlet tissue at two canopy positions were assessed for glasshouse seedlings and 9-year-old hoop pine (Araucaria cunninghamii Ait. ex D. Don) trees from 22 open-pollinated families grown in 5 blocks of a progeny test at a water-limited and nitrogen-deficient site in southeastern Queensland, Australia. Significant variations in canopy δ13C, δ18O, and Nmass existed among the 9-year-old hoop pine families, with a heritability estimate of 0.72 for branchlet δ13C from the upper inner canopy position. There was significant variation in canopy δ13C of glasshouse seedlings between canopy positions and among the families, with a heritability estimate of 0.66. The canopy δ13C was positively related to canopy Nmass only for the upper outer crown in the field (R = 0.62, p < 0.001). Phenotypic correlations existed between tree height and canopy δ13C (R = 0.370.41, p < 0.001). Strong correlations were found between family canopy δ13C at this site and those at a wetter site and between field canopy δ13C and glasshouse seedling δ13C. The mechanisms of the variation in canopy δ13C are discussed in relation to canopy photosynthetic capacity as reflected in the Nmass and stomatal conductance as indexed by canopy δ18O.
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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".