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Stability of boreal forest stands during recent climate change: evidence from Landsat satellite imagery

2001· article· en· W2118297844 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

aboutThe title or abstract carries a Canadian signal from the geographic lexicon.
no affNo Canadian affiliation: this work is invisible to an affiliation-only frame.
No Canadian affiliation. An affiliation-only frame, the usual design, would never have seen this work. It is one of the works that make the case for inverting the frame.

Bibliographic record

VenueJournal of Biogeography · 2001
Typearticle
Languageen
FieldEarth and Planetary Sciences
TopicTree-ring climate responses
Canadian institutionsnot available
Fundersnot available
KeywordsTundraTaigaEcotoneNormalized Difference Vegetation IndexClimate changeSatellite imageryPhysical geographyVegetation (pathology)Tree lineBorealGeographyEnvironmental scienceClimatologyEcologyEcosystemRemote sensingForestryShrubGeology

Abstract

fetched live from OpenAlex

Aim To detect possible expansion of boreal forest stands in response to recent warming. Previous modelling studies have concluded that major shifts in vegetation patterns, including changes in boreal forest extent, could arise during the next two centuries under global warming scenarios. However, field investigations of tree stands at ecotones have so far revealed little indication of stand response to warming during the last 100 years. This study uses a c. 25‐year record of Landsat satellite observations to quantify changes in forest stand extent in two areas of northern Canada. Location Two regions of northern Canada, near Richmond Gulf, Quebec, and Great Slave Lake, north‐west Territories. Methods Normalized‐difference vegetation index (NDVI) plots across forest‐tundra boundaries were obtained from radiometrically corrected Landsat imagery acquired during the 1970s and 1990s. These curves were evaluated to look for changes over the c. 25‐year period related to forest stand expansion. Results Although forest‐tundra boundaries could be clearly mapped from the satellite data, no obvious change in forest boundaries was apparent during the duration of the image time series, constraining recent geographical expansion rates to <200–300 m per century. Also, no evidence for local expansion of forest stands (e.g. within sheltered valleys) was found. Main conclusions The results are consistent with field observations, and suggest that, at the moment, boreal forest extents remain basically stable. This may reflect inherent lags between forest response and climate change, or competitive pressures between tree stands and surrounding tundra and herbaceous vegetation.

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.

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.066
Threshold uncertainty score0.559

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.001
Science and technology studies0.0000.000
Scholarly communication0.0000.001
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 head0.039
GPT teacher head0.255
Teacher spread0.217 · 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