The angular distribution of diffuse photosynthetically active radiation under different sky conditions in the open and within deciduous and conifer forest stands of Quebec and British Columbia, Canada
Bibliographic record
Abstract
The angular distribution of diffuse photosynthetically active radiation (PAR) was characterised in the open and beneath deciduous and conifer forests in Quebec and British Columbia, Canada, under overcast and clear sky conditions, using a restricted field of view light sensor and hemispherical canopy photographs.The angular distribution of PAR was described by the relative light reading (RLR).In the open on overcast days, light was best characterized using the standard overcast sky distribution with the light intensity at the zenith set to four to five times greater than the light intensity at the horizon.RLR under forest stands was found to decrease with decreasing elevation angles under both overcast and clear sky conditions.Aspen (Populus tremuloides Michx.) and Jack pine (Pinus banksiana Lamb.) stands transmitted more light from a relatively wider angle around the zenith than the spruce (Picea glauca (Moench) Voss and Picea mariana (Mill.)BSP) stands, which transmitted light mainly from the zenith.RLR estimated with the hemispherical canopy photographs (RLR hc_corr ) generally provided a comparable prediction of the effect of the canopy composition on the angular distribution of PAR. coniferous forest / deciduous forest / diffuse radiation / photosynthetically active radiationRésumé -Distribution de la radiation photosynthétiquement active sous différentes conditions de ciel en milieu ouvert et sous peuplements forestiers de feuillus et de conifères au Québec et en Colombie-Britannique, Canada.La distribution angulaire de la radiation photosynthétiquement active (PAR) a été mesurée en milieu ouvert et sous peuplements de feuillus et de conifères situés au Québec et en Colombie-Britannique lors de journées nuageuses et ensoleillées à l'aide d'un senseur à angle restreint et de photographies hémisphériques.La distribution angulaire du PAR a été estimée par une lecture de lumière relative (LLR).En milieu ouvert lors de journées nuageuses, LLR déclinait du zénith vers l'horizon, avec des mesures au zénith de quatre à cinq fois plus élevées qu'à l'horizon.LLR mesurée sous couvert forestier déclinait du zénith vers l'horizon lors de journées nuageuses et ensoleillées.Les peuplements de peupliers (Populus tremuloides Michx.)et de pins gris (Pinus banksiana Lamb.) ont transmis relativement plus de PAR sous un angle plus large autour du zénith que les peuplements d'épinettes (Picea glauca (Moench) Voss et Picea mariana (Mill.)BSP) qui ont principalement transmis du PAR autour du zénith.La distribution angulaire du PAR estimée avec les LLR mesurées avec la photographie hémisphérique sous les différents couverts forestiers correspondait de façon générale aux résultats obtenus avec le senseur.forêt de conifères / forêt feuillue / rayonnement diffus / rayonnement photosynthétiquement actif
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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 | 0.001 |
| 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".