Depth of calcium uptake by sugar maple (Acer saccharum Marsh.) and its relationships with climatic extremes
Pourquoi ce travail est dans la base
Une base qui oublie comment elle a trouvé un travail ne peut pas être vérifiée. Voici les voies qui ont admis celui-ci.
Notice bibliographique
Résumé
Sugar maple (Acer saccharum Marsh.) has experienced diebacks in many parts of its range; these declines have caused researchers to consider the many connected factors governing tree health. Altered availability of base cations due to acidic deposition and climatic extremes (drought, late winter freeze-thaw cycles) have been identified as two main causal stressors. To predict the role of climate on Ca nutrition, I investigated the relationship between the climatic factors of temperature, precipitation, water availability and windstorm on temporal changes to depth of Ca source of sugar maple. I hypothesized that the Ca uptake depth would be deeper after windstorms, or under dry or cold conditions, and shallower under warm or wet conditions. The ratio of Ca/Sr can be used to track the source of Ca. Calibration of the relationship between soil and plant Ca/Sr was done by analyzing Ca/Sr ratios in soil extracts of various strengths (H2O, NH4Cl, and ammonium EDTA) and in seedlings of sugar maple grown from natural regeneration on 37 differing sites. The relationships between soil extract Ca/Sr ratios and leaf and stem Ca/Sr ratios were linear, and the slopes of these relationships were different. These findings support the use of Ca/Sr as a tracer to Ca and they highlight the need to calibrate the technique for the plant tissue and the soil extractant used. This technique was then applied to study Ca uptake depth and its relationship with climate in the Hermine watershed, a sugar maple dominated forest in southern Quebec. The Ca/Sr was measured in soil, incremental cores of wood, and leaves. The ratio of Ca/Sr from nine soil profiles decreased with soil depth (r2 = 0.320, p<0.05), providing a signature for depth. Wood cores from ten trees were analysed in five or ten year increments from 1940 to 1999 to provide a long-term trend of Ca nutrition. Sugar maple leaves from 1995-2005 from the same 25 trees were analyzed to determine the annual dynamics of Ca uptake depth and its relationship with climate. Results suggest that the majority of tree Ca is taken from the lowest part of the rooting zone, regardless of the climatic conditions that occurred during this study, although the minor variations were related to the April temperature (r2 = 0.208, p = 0.023) and the June, July and August combined total precipitation (r2 = 0.581, p = 0.006). The effect of the windstorm on Ca uptake depth was only apparent in the area of the forest most visibly affected; Ca uptake was deeper.
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.
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) | 0,001 | 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 | 0,001 | 0,001 |
| 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 découle