Dendroclimatology of yellow cedar (Callitropsis nootkatensis) in the Pacific Northwest of North America
Bibliographic record
Abstract
As the oldest known conifer species in the Pacific Northwest (PNW), yellow cedar (Callitropsis nootkatensis (D. Don) (Spach)) represent an underexploited paleoclimate resource of significant dendroclimatological value. This is the first dendroclimatological study of high elevation yellow cedar within the North Cascades of Washington. In addition, I explored the coherence of yellow-cedar chronologies at the regional scale. I established master tree-ring chronologies and radial-growth characteristics of 50 high-elevation yellow cedars from four sites along the west slope of the North Cascades. Significant (p≤0.05) mean inter-series (r̄=0.61) and inter-site (r̄=0.75) correlations in radial-growth pattern revealed a common limiting factor to yellow-cedar growth within the region. Correlation (r=0.23-0.54) between PRISM climate data and the master chronologies indicated that summer minimum temperatures were the dominant limiting factor of growth for North Cascades yellow cedar. By expanding the sample area to include yellow-cedar chronologies from Mount Rainier WA and Vancouver Island BC, I showed a significant shared pattern of radial growth between these regions. In order to determine the influence of multi-decadal climate forcings associated with the Pacific Decadal Oscillation (PDO), I constructed an averaged PNWtree-ring chronology. Correlation analysis detected the influence of the PDO throughout the chronology. Wavelet analysis revealed the low-resolution (150-250 year) influences of temperature across the regional chronology and significant suppressed growth at all sites in response to stratospheric volcanic eruptions during the 1810's. Further sampling and the inclusion of yellow cedar in multi-proxy reconstructions could improve scientific understanding of paleoclimate in the PNW.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| 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".