Changes in needle morphology of shade-tolerant seedlings after partial overstory canopy removal
Bibliographic record
Abstract
Recent studies with early-successional conifers have shown a correlation between changes in light regimes and changes in needle morphology. The objective of this study was to test the hypothesis that needles of late-successional conifers also respond to increased irradiance. We compared needle morphology of three co-occurring conifers, grand fir (Abies grandis (Dougl. ex D. Don) Lindl.), subalpine fir (Abies lasiocarpa (Hook.) Nutt.), and Engelmann spruce (Picea engelmannii Parry ex Engelm.). Morphological characteristics were examined for 4 years across three light environments: (1) open-canopy stands with 64% transmittance, (2) stands with 63% transmittance after a partial overstory removal treatment, and (3) closed-canopy stands with 29% transmittance. Needle width and length differed by year, but not by light environment. Mean stomatal density differed across years for all three species and increased with increasing irradiance for subalpine fir and Engelmann spruce. The number of mesophyll layers and the size of individual palisade mesophyll cells did not differ among the different light environments. The number of epidermis cell layers in each species was insensitive to changes in light environment and time. Our results indicate that these three conifers were unable to morphologically adapt their needles to an increase in light transmission caused by the partial removal of overstory canopies.
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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 | 0.000 | 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 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".