Effects of variation in carbon, nitrogen, and phosphorus molarity and stoichiometry on sex determination in the fern <i>Ceratopteris richardii</i>
Bibliographic record
Abstract
Carbon (C), nitrogen (N), and phosphorous (P) are needed by all organisms for basic biological processes. When an individual macronutrient is not accessible, nutrient limitation occurs. The stochiometric balance between multiple nutrients and individual concentrations are both vital for normal growth and development. Labile sex expression in plants is a phenotypic trait predicted to be sensitive to local nutrient conditions because males and females differ in their nutritional demands. We applied concepts from ecological stoichiometry to assess the effects of variation in individual nutrient concentration and multiple macronutrient stoichiometry on sexual development in the fern Ceratopteris richardii Brongn. Manipulation of N, P, and organic and inorganic C was expected to yield variation in the ratio of males to females, consistent with environmental sex-determination theory. Our results suggest nutrient stoichiometry, not strictly concentration, influences sex determination at ambient CO2. However, an early response to population density preempted nutrient effects in elevated CO2 environments with exogenous glucose, in which C. richardii gametophytes presumably grow naturally. Although sex determination is not nutrient-dependent in the latter environment, C:N in the dry mass of meristic gametophytes is influenced by the external nutrient context, suggesting sex determination takes place before abiotic environmental factors subsequently influence plant nutrient uptake.
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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) | 0.001 | 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".