Seasonal Variation in the Nectar Sugar Concentration and Nectar Quantity in the Western Prairie Fringed Orchid, Platanthera praeclara (Orchidaceae)
Bibliographic record
Abstract
The endangered western prairie fringed orchid, Platanthera praeclara, is found in remnant tall grass prairie in the central plains of North America. Platanthera praeclara is pollinated by several species of hawkmoths (Sphingidae) in Canada. There is minimal overlap between the flight period of hawkmoth pollinators and the flowering period of the Canadian orchid population, with orchids normally flowering at the end of the hawkmoth flight period. This study was designed to determine if orchids produce more nectar and higher concentrations of sugars in the nectar at the beginning of the flowering period coinciding with maximal pollinator flight times. As pollinators are nocturnally active, we also determined if orchids produce more nectar or nectar with increased concentrations of sugars during the night versus the daytime. Nectar sugar concentration and the amount of nectar per flower were highest at the beginning of the flowering period, and significantly decreased as the season progressed. Nectar volume increased in the evening and during the night but sugar concentration remained relatively unchanged. We examined nectar volume and sugar concentration by flower position, as the majority of the flowers encountered by pollinators in the first few days of the bloom period were lower-positioned flowers due to the sequential flowering nature of the orchid. Within the inflorescence, lower-positioned flowers had higher sugar concentrations in comparison to higher-positioned flowers at the start of the flowering period, but sugar concentrations converged as the season progressed. There was no difference in the amount of nectar present in low- or top-positioned flowers. Orchids may show increased nectar sugar concentrations and amounts at the beginning of the flowering period to capitalize on the presence of hawkmoth pollinators.
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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".