Climatic determinants of acorn size and germination percentage of Quercus rugosa (Fagaceae) along a latitudinal gradient in Mexico
Bibliographic record
Abstract
Background. Abiotic constraints, historical effects of the last glaciation, and differential dispersal, have been proposed as potential explanations to account for the latitudinal decrease in acorn size of wide-ranging oak species distributed in the U.S. and Canada.
 Hypothesis. We specifically tested the abiotic constraints hypothesis on oak acorn size in a geographical area without the counfounding influence of glaciation and related dispersal history.
 Data description. Acorns from seven populations of the white oak Quercus rugosa were collected, encompassing the distribution of the species in Mexico.
 Study site and years of study. Mexico, 2009-2010.
 Results. Acorn length, width, mass and volume differed significantly among populations and indicated a marked clinal latitudinal reduction in acorn size. A multiple regression model revealed that this reduction in size (measured as acorn volume) can be explained by two important bioclimatic variables (growing season precipitation and growing season degree-days above 5 °C), while spatial variables (latitude and longitude) are not significant. Furthermore, germination percentage was significantly correlated to acorn mass and volume.
 Conclusions. The main determinants of the latitudinal decline in acorn size are climate factors constraining seed development. This decline is maladaptive for seedling establishment, with important implications for the delination of northern limits of species ranges.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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".