Cold hardiness in coastal, montane, and inland populations of<i>Populus trichocarpa</i>
Bibliographic record
Abstract
Freezing tolerance was studied in laboratory and field tests using black cottonwood, Populus trichocarpa Torr. & Gray, clones collected from eight populations within the coastal, montane, and inland regions of the Pacific Northwest. Freezing tolerance varied among different populations and was dependent on growing environment. Clones from coastal populations grown in a coastal common garden (Puyallup, Wash.) had 50% less injury in laboratory tests compared with the same clones grown in an inland common garden (Pullman, Wash.). In contrast, clones from inland populations grown in an inland common garden had 50% less injury in laboratory tests compared with the same clones grown in a coastal common garden. Freezing tolerance also varied between coastal populations. In field tests at the inland common garden, clones from inland and montane populations had less freezing injury compared with clones from coastal populations. Leaves on 50% of the clones with coastal origins were killed by the first fall frosts compared with 25% for clones with inland origins. Subsequently, 50% of the coastal clones exhibited winter injury following the winters of 1993-1994 and 1994-1995 at the inland common garden. Clones from inland populations exhibited little or no winter injury. The specific tissues injured during freezing tests varied among clones. Populus trichocarpa is a species offering considerable variation for selection to local environments, and therefore, the source of material should be an important consideration in hybrid poplar breeding programs.
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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 | 0.001 | 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) | 0.001 | 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".