Radial variations in cation exchange capacity and base saturation rate in the wood of pedunculate oak and European beech
Bibliographic record
Abstract
In a mixed forest stand on an ochreous brown earth in the Belgian Ardennes, pedunculate oak (Quercus robur L.) and European beech (Fagus sylvatica L.) have outwardly decreasing cation concentration profiles in wood. To test if these profiles can be ascribed to endogenous factors or to decreased availability of cations in the soil, radial profiles of water-soluble, exchangeable, and total cations and of cation exchange capacity (CEC) of wood were determined. In both species, [Formula: see text]75% of K is in the water-soluble form so is of little use for dendrochemical monitoring. About 80% of Mg is adsorbed on wood exchange sites. For Ca, 30 (beech) to 60% (oak) of total content cannot be extracted by SrCl2 and is, thus, relatively immobile in wood. Wood CEC decreases from pith to bark in European beech and from pith to outer heartwood in pedunculate oak. Decreasing profiles of exchangeable Ca and Mg in pedunculate oak and exchangeable Ca in European beech are strongly constrained by CEC and, thus, are not related to environmental change. Base cation saturation rate shows no consistent radial change in either species. European beech maintained much higher base cation saturation rate than pedunculate oak, although both species had similar CEC. In conclusion, the results do not provide convincing evidence for a significant change in nutritional status of pedunculate oak and European beech in the Belgian Ardennes due to atmospheric pollution.
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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 | 0.000 |
| 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) | 0.000 | 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".