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Record W131088920

Light transmission and understory vegetation in two old-growth riparian stands : a study in spatial pattern

2003· dissertation· en· W131088920 on OpenAlex
Audrey Elizabeth Roburn

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.

fundA Canadian funder is recorded on the work.
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

VenueSummit (Simon Fraser University) · 2003
Typedissertation
Languageen
FieldEnvironmental Science
TopicEcology and Vegetation Dynamics Studies
Canadian institutionsnot available
FundersNatural Sciences and Engineering Research Council of Canada
KeywordsUnderstoryTransectGeographyEcologyVegetation (pathology)Environmental scienceSpatial ecologyCanopyPhysical geographyBiology
DOInot available

Abstract

fetched live from OpenAlex

Characterizing the structure of old-growth forests is crucial to understanding their ecological dynamics.I examined canopy openness, understory gap-light, and understory vegetation in two old-growth floodplain stands in southwestern British Columbia.The younger stand was in the "horizontal diversification" stage, and the older stand was in the "pioneer cohort loss" stage and contained a large vine maple gap.I determined spatial patterning of canopy openness and understory gap-light using hemispheric photography at closely spaced (2m) photosites on perpendicular transects, and explored how gap-light transmission, space, and distance from water features affected understory vegetation composition.The frequency distribution of light and openness values in the older stand had a mode at low values in conifer-dominated areas undergoing pioneer cohort loss, and a long tail of variable and higher values in the vine maple gap.The younger stand exhibited a bimodal distribution.Spatial autocorrelation of light and canopy openness values between photosites was clearly significant on all transects, with positive spatial autocorrelation significant to at least 12.5 metres in all cases.Depending on the goals of future studies in similar forests, either a sampling step of 30m or a systematic cluster sampling design is recommended.Patterns of understory gap-light on the transects varied over the small scale of 100m, a scale considerably smaller than the typical scale of forest management in British Columbia.Comparatively high and spatially and temporally variable values of gap-light transmission in the vine maple gap, combined with a distinct understory community in the vine maple gap, reaffirm the ecologically distinct role of vine maple in coastal temperate rainforests of the Pacific Northwest.Multivariate analysis showed that gapiii light transmission did not have a large influence on understory composition at the measurement scale of this study.I n the younger stand, distance to small streams explained some of the variation in understory communities.Restoration efforts aiming to re-establish old-growth conditions in floodplain forests of the Pacific Northwest need to account for variable overstory spatial pattern over small scales (loom), the distinct role of hardwood patches such as vine maple gaps, and the influence of small streams on understory plant communities.This project is the culmination of the combined efforts of so many people they are almost too numerous to list.I extend my deepest gratitude to Ken Lertzman and Gord Frazer, both of whom were always willing to answer my questions and guide my progress.Thanks are also due to

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)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesMeta-epidemiology (narrow)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.925
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

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

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 head0.007
GPT teacher head0.216
Teacher spread0.208 · 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