Frost hardiness of balsam poplar (Populus balsamifera L.) during the spring dehardening period / by Steven R. Watson
Bibliographic record
Abstract
Changes in the frost hardiness of balsam poplar (Populus balsamifera L.) \ncuttings from four populations along a latitudinal transect from N. Wisconsin to \nBearskin L, Ontario, were examined during the spring of 1987. Hardiness levels of \ndormant stem cuttings from the two extreme populations were examined after \nvarious incubation periods, under two different dehardening temperature regimes, \nwith a standard freezing test (freezing temperatures: -S.-l 1 ,-19, and -27? C). \nNorthern clones were less susceptible to frost injury than southern clones during \nthe spring dehardening period, and this phenomenon was closely related to the \ntendency of northern clones to remain dormant longer than southern clones. High \nwithin-population variation was also noted in hardiness levels and bud break \ncharacteristics. Leaf tissue dehardened more rapidly than stem tissue, and the \ndehardening process occured more rapidly at the higher incubation temperature. \nA second study in which cuttings from the four provenances were subjected \nto a series of controlled freezing temperatures (-3,-6,-9,-12,-18, and -24? C) at \nparallel developmental stages revealed that provenance differences in frost injury \nwere essentially a function of differential shoot phenology at the time of freezing. \nCuttings were hardy to -18? C when leaf expansion first became visible, and could \nbe subjected to -12? C without injury when the newly expanding shoot became \nvisible, indicating that an attenuated form of hardiness may exist even when the \nshoots are actively growing.
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 | 0.000 | 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) | 0.001 | 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".