Notice bibliographique
Résumé
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.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,001 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».