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Record W2339226880 · doi:10.14288/1.0106266

Water relations in the Douglas-fir region on Vancouver Island

2012· article· en· W2339226880 on OpenAlexaboutno aff
R. G. McMinn

Bibliographic record

VenuecIRcle (University of British Columbia) · 2012
Typearticle
Languageen
FieldEarth and Planetary Sciences
TopicClimate change and permafrost
Canadian institutionsnot available
Fundersnot available
KeywordsDouglas firHistoryGeographyForestry

Abstract

fetched live from OpenAlex

In an evaluation of the role of water relations in forest distribution and growth in the Douglas-fir region on Vancouver Island, a section of the Nanaimo River Valley, lying from five to twelve miles inland from the east coast, was chosen as a suitable study area to exemplify conditions in the central mountains and on the eastern side of southern Vancouver Island. The study was conducted in mature stands typical of the principal forest associations found within the range of climates, topographies and soils represented in this area. The vegetation and soils of twenty-four, quarter-acre plots were analysed in order to characterize stands and relate such characteristics to the influence of water relations. The soil moisture regimes and microclimates of each plot were defined by measuring soil moisture levels, precipitation beneath the tree canopy, evaporation rates and soil and air temperatures. Variation in soil moisture contents was followed over a thirty-month period from July, 1951 to November, 1953, and precipitation and maximum/minimum temperatures at various open stations were measured at monthly intervals from June, 1951 until December, 1956 in order to delineate climatic variations within the study area. It was concluded that variation in soil moisture regimes was a most significant factor in the differentiation of sites. In moist, relatively nutritive soils Pseudotsuga menziesii so completely dominated Tsuga heterophylla that the latter species was restricted to the secondary canopy and formed only a small proportion of stand volume. In strongly leached soils, the growth of Pseudotsuga and Tsuga was impaired, so that trees of both species were smaller than in more nutritive soils. Where strongly leached soils were moist throughout the growing season, Tsuga could compete with Pseudotsuga on nearly equal terms and both species reached the upper tree canopy. In droughty, leached soils the growth of Tsuga was more impaired than the growth of Pseudotsuga. and Tsuga formed small to negligible proportions of stand volume. Thuja plicata appeared in the upper tree canopy only on moist to very wet, relatively nutritive sites. The dominant influence in the geographical location of the Douglas-fir region on Vancouver Island appears to be its rainshadow climate. Within this region of low summer rainfall Pseudotsuga can dominate other species on nearly all sites. In wetter climates, outside pronounced rainshadow areas, stands dominated by Pseudotsuga are evidently confined to moist, relatively nutritive sites. Within the different climatic areas encountered, topographic position and concomitant climatic and edaphic influences would seem largely responsible for site differentiation. Such site differentiation followed a definite catenary sequence, which regulated the sequence of forest associations on hillsides. Differences in local topography, aspect, parent material, soil texture and soil depth, however, may cause variation from the typical arrangements.

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)0.000
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: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.356
Threshold uncertainty score0.716

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0010.000
Scholarly communication0.0000.000
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 head0.020
GPT teacher head0.173
Teacher spread0.154 · 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

Citations5
Published2012
Admission routes1
Has abstractyes

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