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Modern Pollen and Conifer Stomates from North-central Siberian Lake Sediments: Their Use in Interpreting Late Quaternary Fossil Pollen Assemblages

2001· article· en· W2062099333 on OpenAlex
Michael F. J. Pisaric, Glen M. MacDonald, Les C. Cwynar, Andrei Velichko

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.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.
fundA Canadian funder is recorded on the work.

Bibliographic record

VenueArctic Antarctic and Alpine Research · 2001
Typearticle
Languageen
FieldEarth and Planetary Sciences
TopicGeology and Paleoclimatology Research
Canadian institutionsUniversity of New BrunswickQueen's University
FundersNatural Sciences and Engineering Research Council of Canada
KeywordsTundraPollenVegetation (pathology)TaigaEcologyPeatLarchHoloceneTree linePhysical geographyCyperaceaeGeologyEnvironmental scienceGeographyArcticClimate changeBiologyPaleontologyPoaceae

Abstract

fetched live from OpenAlex

To determine the modern relationship between pollen and stomate deposition and vegetation, surface sediments from 26 lakes along the Lena River in northeastern Siberia were analyzed for pollen and conifer stomate content. The lakes sampled, crossed a vegetation gradient from tundra, forest-tundra, to closed boreal forest. The pollen spectra of tundra lakes are dominated by Betula and Alnus. Cyperaceae and Poaceae are also abundant. Forest-tundra lakes are dominated by Betula and Alnus, but contain lower percentages of Artemisia than tundra lakes. Forest pollen spectra are also dominated by Betula and Alnus pollen, however, forest lakes contain greater percentages of Larix pollen. Principal components analysis indicates that forest and tundra sites were distinct from one another, but considerable overlap exists between forest-tundra and forest and tundra pollen assemblages. Larix stomates were abundant in all samples from regions where trees are currently present except for one lake. Small numbers of Larix stomates were found in tundra lakes, likely due to the redeposition of older material from eroding peat banks. It is likely that this process also contributed some older pollen to modern lake sediments as well. Principal components analysis was used to compare fossil samples from a lake-sediment core to the modern spectra. Early Holocene vegetation assemblages, dominated by herb and Betula shrub tundra and subsequent Larix forests, do not have modern pollen analogs in the lower Lena River region. Modern pollen analogs developed after 6 ka BP, when forest vegetation developed around the site. This was gradually replaced by modern tundra after 3.5 ka BP.

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 categoriesInsufficient payload (model declined to judge)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.072
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.001
Scholarly communication0.0000.001
Open science0.0000.000
Research integrity0.0000.001
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 head0.043
GPT teacher head0.286
Teacher spread0.243 · 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