No influence of water limitation on the outcome of competition between diploid and tetraploid<i>Chamerion angustifolium</i>(Onagraceae)
Bibliographic record
Abstract
Summary Polyploid plants often occupy different geographic ranges than their diploid progenitors, but the causes of this segregation are poorly understood. Differential competitive abilities of cytotypes across an environmental gradient could be responsible for these observed geographic range differences. Cytotypes of Chamerion angustifolium (Onagraceae) are mostly allopatric, and prior research indicates that tetraploids are more physiologically tolerant of water limitation and occupy drier habitats than diploids. We hypothesized that tetraploids are stronger competitors than diploids in soils where water is limited, which allows them to persist in dry habitats while diploids cannot. We grew both cytotypes together in competition under water‐limited and well‐watered conditions. We varied both total plant density and the relative frequency of cytotypes among pots, which allowed us to separate the effects of intra‐cytotypic and inter‐cytotypic competition. Both diploid and tetraploid plants were smaller in the water‐limited treatment than in the well‐watered treatment. Nevertheless, there were no differences in the relative strength of intra‐cytotypic and inter‐cytotypic competition experienced by either cytotype across the watering treatments, indicating that diploids and tetraploids had equal competitive abilities in both treatments. Synthesis . Competition for limiting resources is often proposed as a mechanism causing ecological and geographic segregation between diploid and polyploid cytotypes. Our results do not support the hypothesis that tetraploid Chamerion angustifolium plants are stronger competitors than diploids when water is limited. A differential ability to compete for water is likely not responsible for the observed ecological and geographic segregation between cytotypes in this species. Competition may not be a general mechanism that causes segregation between diploid and polyploid cytotypes in nature.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 teacher head, 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".