Methane efflux from boreal wetlands: Theory and testing of the ecosystem model Ecosys with chamber and tower flux measurements
Bibliographic record
Abstract
A robust model of CH4 emission from terrestrial ecosystems should be capable of simulating the temporal and spatial variability that characterizes field measurements. Such a model should couple a biologically based treatment of microbial CH4 transformations with a physically based treatment of heat, solute, and gas transfer vertically and laterally through soils. These processes are coupled in the ecosystem model Ecosys, which was tested against CH4 effluxes measured with surface chambers and a flux tower at a beaver pond in the BOREAS Northern Study Area. Spatial and temporal variation of CH4 effluxes in the model encompassed that measured by surface chambers and the flux tower. Both modeled and measured CH4 effluxes rose from <0.05 μmol m−2 s−1 and <0.01 g C m−2 d−1 at sites above the pond to >1.0 μmol m−2 s−1 and >0.5 g C m−2 d−1 at the pond margin. Larger effluxes occurred in the model when warming pond sediments generated episodic bubbling events. Annual CH4 effluxes in the model rose from <1 g C m−2 at sites above the pond to 76 g C m−2 at the pond margin. Annual totals included several brief but rapid efflux events during thawing and warming of soil and pond sediments that are frequently missed by surface measurements. Annual CH4 effluxes predicted after 100 years under an IS92a‐driven climate change scenario rose by ∼20% from the pond, but changed little from the surrounding landscape, indicating topographic variation in response of CH4 effluxes to climate change.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.002 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 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".