The effects of flooding regime on the rare Atlantic coastal plain species <i>Hydrocoytle umbellata</i>
Bibliographic record
Abstract
The hydrological regime on many lakes is changing through climate change, construction of dams, and land-use changes. We examined the effects of flooding regime on growth and development of the endangered semiaquatic species, Hydrocotyle umbellata L. (water pennywort), in a greenhouse experiment. Growth was twice as fast under dry, above-water (terrestrial) conditions as under flood conditions. Depth of flooding (15 or 30 cm) had little impact. Short-term floods at either the middle or end of the growing season were just as damaging as continuous flooding. The decrease in growth under flood conditions was largely due to a temporary reduction in unit leaf rate (growth per unit leaf area) rather than to a reduction in leaf area ratio (leaf area per unit mass). Flooded plants allocated more resources to the production of petioles at the expense of reproductive structures and to a lesser extent, belowground structures. They also produced fewer, larger leaves with more stomata on the upper than on the lower surface. These changes in structure were largely restricted to new leaves produced under flood conditions; most of the mature leaves produced in a terrestrial environment senesced upon flooding. Chemical analysis of tubers produced by plants grown under terrestrial conditions indicates that these structures function in carbohydrate storage. The likely impact of changes in hydrological regime on this endangered species is discussed in light of these findings.
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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".