Physiological and Morphological Variation in Balsam Fir Provenances Growing in New Brunswick, Canada
Notice bibliographique
Résumé
There is a need to understand the physio-morphological responses of northern tree species to climate change. The hypothesis of the current study was that provenance and light intensity were both influential in the control of intrinsic water-use efficiency (iWUE). Diameter at breast height (DBH)-increment was hypothesized as being more affected by provenance. Intrinsic water-use efficiency (iWUE), the ratio of photosynthesis (A) to stomatal conductance (gs), was assessed in foliage under two levels of photosynthetically active radiation (PAR; i.e., 300 and 1200 μmol m−2 s−1) in 63-year-old balsam fir [Abies balsamea (L.) Mill.] provenances derived from seed sources from across the species’ natural range (namely, within 44–51° N latitudes and 53–102° W longitudes) and cultivated in a common garden in eastern Canada. Diameter at breast height (DBH) of provenances from the common garden were measured when they were 42 and 58 years old (DBH1998, DBH2014). The results confirmed the hypotheses regarding the roles of provenance on iWUE and DBH (p < 0.05), but showed a diminished role of PAR on iWUE. The lowest and highest mean iWUE and DBH among the provenances ranged between 0.028 and 0.031 and 0.079–0.083 μmol mmol−1 and 11.82–12.78 and 16.38–18.44 cm, respectively. Stomatal conductance of balsam fir had a strong relationship with iWUE at both light settings, whereas A had a weaker relationship with iWUE. There were no significant relationships between iWUE at the two light settings and climatic variables at the provenance source (p > 0.05). Diameter at breast height in 2014 was significantly greater than DBH1998 (p < 0.05). The relationships between DBH2014 and climatic variables at the provenance source were statistically significant (p < 0.05). There was a significant positive relationship between iWUE and DBH measured in 2014. Survivorship of provenances was shown to vary with DBH-increment. The results show that for present-day and future forest management, (i) selection in balsam fir, in relation to iWUE should ideally be based on a criterion of intraspecific stomatal conductance; (ii) shade tolerance of balsam fir, population differentiation, and consistent pace of DBH-growth under variable climatic conditions are important factors in the species’ sustained growth under changes in forest dynamics projected to accompany changes in regional climate; (iii) temperature variables are strong indicators of DBH-increment in balsam fir; (iv) the effect of tree size on its survival is maintained under variable climatic conditions; and (v) there is a clear association between iWUE and the species’ radial growth.
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 distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| 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 | 0,000 | 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) | 0,000 | 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 tête enseignante, 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 ».