White spruce (<i>Picea glauca</i>) population differences in needle anatomy, foliar water uptake and aquaporin expression indicate trade-offs between hydraulic safety and productivity
Bibliographic record
Abstract
White spruce is a leading species across nearly the entirety of the North American boreal forest, occurs under a wide range of climate conditions and has been reported to take up water through its needles. As such, the species represents a good model organism in which to research adaptation to climatic factors through structural and physiological mechanisms. We used branch samples obtained from a 40-year-old range-wide provenance experiment to relate the climate of origin to needle anatomy, foliar water uptake and aquaporin expression under simulated drought conditions. Provenances with cold and dry source climates generally had thinner needle hypodermis layers and Casparian strips, and lost more water during dehydration. However, foliar water uptake, which involved the regulation of aquaporin water channel gene expression, was also highest in these provenances. We propose that the absence of foliar anatomical traits that would typically be associated with drought adaptation represents a previously undocumented drought adaptation strategy: a thin hypodermis and Casparian strip with aquaporin-mediated water uptake enables distinct spruce populations to leverage foliar wetting events such as snowmelt, dew or light rain, when water uptake in roots is seasonally restricted by low soil temperatures. However, this strategy is vulnerable to severe or prolonged drought events.
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 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".