Effects of precommercial thinning on annual radial growth and wood density in balsam fir (Abies balsamea)
Bibliographic record
Abstract
This study examined effects of precommercial thinning (PCT) on annual radial growth (ring width) and wood density in balsam fir [Ahirs hnl.samra (L.) Mill.].In addition, the responses to PCT were measured and compared at several stem heights (0.2 m, 0.7 m, 1.3 m, 3 In, 5 m, 7 In, 9 m).Fiftyfour trees were collected from plots subjected to moderate thinning (nominal stand density of 2,150 stemslha), and light thinning (nominal stand density of 4,200 stemslha), and from control plots.Ring width and wood density of individual rings were measured by X-ray densitometry.Our results show that in balsam fir the annual radial growth rate showed a positive response to PCT, especially in the low part of the stem (up to 5 m high), and this response lasted for 7 years.To achieve a significant increase in annual diameter growth in t h i ~ species, however, a moderate thinning intensity is needed.This study also revealed that the response of annual radial growth to PCT was limited primarily to the earlywood width, whereas the latewood width showed little response.As a result, the latewood percentage was affected by the moderate thinning.The light thinning and the control plots, however, had a comparable earlywood width and latewood percentage.Both earlywood density and latewood density showed little response to PCT.However, the wood density of growth rings tended to decrease following the moderate thinning, due to a decreased latewood percentage.In addition, the moderate thinning might somehow reduce the intra-ring variation in wood density and thus produce more uniform wood.This study also revealed that the responses to thinning in this species tended to weaken appreciably with increasing stem height.The remarkable responses were observed in the low part of the stem (up to 5 nl high), whereas little response was found at the upper part of the stem.As a result, an increased stem taper may result from PCT in balsam fir.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.002 |
| Science and technology studies | 0.001 | 0.011 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.001 |
| 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".