A Study of Substrate Variability and the Distribution of Opuntia cespitosa (Cactaceae) from Southern Ohio to Central Alabama, USA
Bibliographic record
Abstract
Opuntia cespitosa (Cactaceae, previously known under the synonym O. humifusa) is found over eastern North America, yet its populations are very sparse and small despite effective vegetative reproduction. Their edaphic preferences are poorly known, and may limit the distribution and success of the species. Soils were sampled for %O.M. (organic matter), %sand, %silt, %clay, pH, and kg/ha of P, K, Ca, Mg, and Zn in 33 populations over a wide area of eastern North America. Tissue testing was carried out in three populations. Opuntia cespitosa occurs over a wide variety of nutrient conditions and soil textures, including both acidic and alkaline soils, though soil nutrients were generally poor and thin. Populations of the species occurred on soils with very high levels of calcium that could be toxic for other plants, exceeding 20,000 kg/ha in some areas. Plants in these areas also had high Ca tissue levels, also common in desert cacti. Kruskal-Wallis and Spearman′s correlation results suggest that population size was not related to the soil attributes tested, but does indicate that areas mowed by large mowers have larger populations. This may be the result of local vegetative spread of fragments by mowers.
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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 | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 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".