Dynamics and morphology of giant circular patterns of low tree density in black spruce stands in northern Quebec
Bibliographic record
Abstract
Giant circular patterns of low tree density in black spruce (Picea mariana) stands were investigated in the Abitibi region of Quebec. We used dendrochronological techniques to test the hypotheses that ring patterns of low tree density are caused either by radial changes in spruce mortality or productivity. Seven circles were sampled. We found no gradient in the age of spruce along circle radii suggesting that rings of low tree density do not expand radially, that is, they are not spatially dynamic entities. The results indicate, however, that spruce trees were less dense and productive within the rings due to excessive moisture in the soil. Measurements of surface elevation, thickness of the organic layer and elevation of the mineral substrate across the circles revealed that a depression in the mineral soil beneath the rings traps the surface water and this area of poor drainage seems to prevent the establishment of black spruce within the rings. The origin of the ring-shaped depressions was attributed to geological or geomorphological causes.Key words: black spruce, Picea mariana, mortality, productivity, rings, geomorphology.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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) | 0.000 | 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 teacher head, 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".