Improving site index estimates for pine and spruce plantations: a case study in the sub-boreal spruce zone in British Columbia
Bibliographic record
Abstract
Site index (SI) expresses the growth potential for a species on a given site. Three SI determination methods were used for each managed stand sampled in the southern portion of the Prince George Timber Supply Area (TSA): forest inventory, calculated growth intercept or height over age, and site index biogeoclimatic ecosystem classification (SIBEC). Interior spruce and lodgepole pine leading stands were sampled in the Bowron Valley and only pine stands were sampled in the rest of the TSA. In the Bowron Valley for both species, calculated SI was greater than SIBEC SI, which was greater than inventory SI. Increases were greater for spruce. In the remaining pine areas sampled, the same relationship was observed. Pine yield model projections indicate mean annual increment (MAI) culmination occurred 5.7 and 16.4 years sooner for calculated SI compared with SIBEC and inventory SI, respectively, with yields increasing by 8% and 13%. The increases could be due to improved silviculture, tree response to climate change or a combination of the two. Differences could result in a mid-term timber supply available sooner or a greater yield at planned harvest age. This is particularly important in areas attacked by mountain pine beetle.
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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 | 0.001 | 0.005 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| 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".