Sex ratio mediated pollen limitation in the dioecious herb Antennaria dioica
Bibliographic record
Abstract
We examined how population structure affects seed set and recruitment in the dioecious plant Antennaria dioica, which is a declining species inhabiting semi-natural grasslands in Sweden. Flowering and sex ratio in A. dioica were studied over 4 y at a local (1.2 km2) scale and over 1 y at a regional (742 km2) scale in southern Sweden. Antennaria dioica was also hand-pollinated during 2y to examine whether sex ratios, male abundance, and distance to nearest male influence the degree of pollen limitation. Seed-sowing experiments were conducted to assess whether recruitment is limited by seed or microsite availability. There was a considerable spatio-temporal variation in both flowering and sex ratios. The regional scale survey showed that patch size and number of patches per site were positively correlated, and small patches of A.dioica tended to have biased sex ratios. Experimental hand-pollinations showed that the degree of pollen limitation increased with increasingly female-biased sex ratios in the closest vicinity of the experimental plants. Thus, even though A. dioica is pollinated by many different insects, a fragmented population structure has a large influence on reproductive performance of A. dioica. The seed-sowing experiments showed that recruitment is limited by a combination of seed and microsite availability. It is therefore plausible that reduced seed production due to pollen limitation translates into reduced recruitment. The results from the local and the regional scale indicate that a large fraction of local patches and populations of A. dioica have decreased sexual reproduction. The conclusion is that A. dioica is likely to be particularly sensitive to habitat fragmentation.
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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".