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Record W2167109245 · doi:10.1139/x11-130

Optimal structure and development of uneven-aged Norway spruce forests

2011· article· en· W2167109245 on OpenAlexvenueno aff
Olli Tahvonen

Bibliographic record

VenueCanadian Journal of Forest Research · 2011
Typearticle
Languageen
FieldEnvironmental Science
TopicForest Management and Policy
Canadian institutionsnot available
FundersAcademy of Finland
KeywordsPicea abiesProfitability indexBasal areaForest managementMaximizationKarstEnvironmental scienceMathematicsForestryEcologyAgroforestryGeographyBiologyMathematical optimizationEconomics

Abstract

fetched live from OpenAlex

Optimal harvesting of Norway spruce ( Picea abies (L.) Karst.) forests is studied applying an individual-tree model for uneven-aged management. Optimization is carried out by gradient-based, large-scale interior point methods. Assuming volume maximization and natural regeneration, it is optimal to apply uneven-aged management. Under artificial regeneration, the result is the reverse. Economically optimal solutions with a 20-year harvesting interval produce an annual sawn timber output of 4.4–2.4 m 3 ·ha –1 depending on thermal zone and interest rate. Before harvest basal area varies between 18 and 12 m 2 ·ha –1 and the diameter of harvested trees between 15 and 33 cm. In contrast with the classic inverted J-structure, optimal steady-state size structure resembles a serrate form. Profitability of even- and uneven-aged management is compared assuming that the initial stand state represents an optimal uneven-aged steady state. A switch to even-aged management is optimal given the most favorable growth conditions and interest rate below 1%–2%. In other cases, it is economically optimal to continue uneven-aged management although volume output remains lower than under even-aged management.

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 imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.001
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.004
Threshold uncertainty score0.008

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.001
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0010.001
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0010.000

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.

Opus teacher head0.047
GPT teacher head0.285
Teacher spread0.238 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

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".

Quick stats

Citations60
Published2011
Admission routes1
Has abstractyes

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