Biological implications of empirical models of winter oxygen depletion
Bibliographic record
Abstract
We compiled data for 23 North American temperate zone lakes to assess three alternative winter O2 depletion models for estimating O2 dynamics from freezing to thawing. Dissolved O2 concentrations were constant or declined slightly for an average of 40 days after freezing and then declined rapidly. Once O2 concentrations reached 13 mg·L1, consumption slowed. No model that we fit captured O2 dynamics shortly after freezing. The best fit was a one-pool exponential decay model after one to four initial data were removed. Photosynthesis and freeze-out estimates suggest that O2 inputs are more important in shallow than in deep lakes. Oxygen decay rates (k) correlated with morphometry in shallow lakes and chlorophyll a, Secchi depth, and the sediment surface area to volume ratio in deep lakes. We hypothesize that the failure of chlorophyll a to correlate with k in shallow lakes is because macrophytes are the primary source of decaying organic matter but have not been included in assessments of winter O2 depletion. Thus, some processes in deep lakes cannot simply be scaled to smaller scales in shallow lakes.
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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 | 0.008 | 0.047 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".