Decomposition of <i>Betula papyrifera</i> leaf litter under the independent and interactive effects of elevated CO<sub>2</sub> and O<sub>3</sub>
Bibliographic record
Abstract
Abstract Litter decay dynamics of paper birch ( Betula papyrifera ) were assessed at the Aspen free‐air CO 2 enrichment (FACE) facility in northern Wisconsin, USA. Leaf litter was decomposed for 12 months under factorial combinations of 360 vs. 560 μL CO 2 L −1 , crossed with 36 vs. 55 nL O 3 L −1 . To differentiate between substrate quality and environment effects, litterbags were placed in their Native Plots of origin or transplanted into the other treatments. CO 2 enrichment, regardless of O 3 concentration, produced poorer quality litter (high C/N, lignin/N and condensed tannins) than did ambient CO 2 (low C/N, lignin/N and condensed tannins). Substrate quality differences were reflected in the mass loss rates ( k ‐values), which were high for litter generated under ambient CO 2 (0.887 year −1 ) and low for litter generated under elevated CO 2 (0.674 year −1 ). The rate‐retarding effects of CO 2 enrichment were neither alleviated nor exacerbated by O 3 exposure. Decay rates varied, however, depending on whether litter was placed back into its plot of origin or transplanted to Common Gardens. The results of this study are species specific, but they have important implications for understanding the processes regulating storage of fixed C and the release of CO 2 from northern forest ecosystems.
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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".