Climate and site factors affecting survival and yield of Douglas-fir in the Cedar-Hemlock ecosystem of the southern interior of British Columbia
Bibliographic record
Abstract
Extended tree lifespans require investments against decay, herbivory, wind and fire. The commercially important conifer Douglas-fir [Pseudotsuga menziesii var. glauca (Beissn.) Franco] was studied to identify conditions affecting its survival and growth in nine planted and four natural study sites in British Columbia. Planted Douglas-fir ranged from 20 to 40 years in age, and natural stands from 63 to 110 years in age. Average survival for all tree species in planted stands was 86% after 30 years and for Douglas-fir in natural stands survival was 60% after 90 years. Armillaria root disease was the principal cause of Douglas-fir mortality in all sites. Mortality in planted stands increased with stand age but slowed by age 35. Planted tree mortality was reduced with greater accumulation of cold temperatures which is thought to affect inoculum potential or contact between inoculum and the host. In older and younger stands, site index was positively related to mortality, probably a direct result of the greater contact with fungal inoculum associated with the larger diameter trees. In older natural stands, mortality increased with stand age and was also positively related to the summer heat moisture (SHM) index thought to be through lower summer rainfall. Mortality impacted negatively on basal area yield, meaning that growth of living trees could not compensate for basal area lost to dead trees.
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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 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 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".