Production and Wind Dispersal of Canada Thistle (Cirsium arvense L.) Achenes
Bibliographic record
Abstract
Quantity, quality and dispersal distance of wind-blown achenes and pappi were determined during the peak time of \ndispersal over twelve site-years in Minnesota during 2006 and 2007. Approximately twice as many pappi than \nachenes were trapped. Wind blown pappi tend to travel near the ground. Most achenes fell near the parent plants \nand their population density declined exponentially with increasing distance. Over 80% of pappi collected did not \nhave an achene attached. Concomitantly, seed production in Canada thistle was monitored for 8 site-years in \nMinnesota. Averaged across years and locations, female Canada thistle shoots that flowered produced an average \nof 38% empty, 17% shrunken, and 44% normal achenes. Male shoots produce about half the number of seedheads \ncompared to female shoots. A low level of hermaphroditic expression was observed in male shoots. Though seed \nproduction by female Canada thistle is extremely variable, when sufficient pollen is available, Canada thistle \nclearly has the potential to generate significant contributions to seedbanks to maintain invasive stands. However, \ndispersal by wind is for the most part, local. Long distance dispersal of significant numbers of healthy achenes \nwould be a rare event.
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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".