Response of Aspen Fine Roots to Soil Compaction on Two Soil Types in the Upper Great Lakes Region
Notice bibliographique
Résumé
Soil compaction caused by timber harvesting can reduce regeneration and \nproductivity in many forested situations. As part of the national Long-term Soil \nProductivity project (LTSP), this study examined the effects of specific soil \ncompaction treatments on the fine-root ( < 2mm) biomass and nutritional status of \naspen (Populus spp.) regeneration in the Upper Great Lakes Region. The three levels \nof soil compaction included no compaction (C0), light compaction (C1), and heavy \ncompaction (C2). Unharvested areas served as controls (NH). The study sites were \nlocated at the Ottawa and Huron-Manistee National Forests in upper and lower \nMichigan, respectively. The soil at the Ottawa site is an Ewen clay (very fine, mixed \nGlossic Eutroboralf); at the Huron-Manistee site the soil is transitional between a \nRubicon (sandy; mixed, frigid Entic Haplorthod) and a Grayling sand (mixed, frigid \nTypic Udipsamment). The LTSP study design also incorporates three levels of \norganic matter removal (merchantable bole removal, whole tree harvest, and whole \ntree harvest plus removal of the forest floor). This study examined the full array of \nsoil compaction within the whole tree harvest level of organic matter removal. \nDuring the growing-season and fall of 1999, soil cores and foliage samples were \ncollected from each treatment level. Aspen fine roots were separated from the fine \nroots of the other species based on external morphology. The aspen root \nidentification was verified using random amplified polymorphic DNA analysis; 90% \nof the root fragments were correctly identified. During the growing season and the \nfall, over 60% of the aspen fine-root biomass was in the top 10-cm of soil. Growing \nseason aspen fine-root biomass was significantly less (p < 0.05) in the compacted \nplots than in the unharvested plots for all sampling depths (NH= 1,129 g m^-3, C0 = \n328 g m^-3, C1 = 650 g m^-3, C2 = 547 g m^-3; for the 0-10 cm depth). Growing season \naspen fine-root biomass was significantly (p < 0.05) greater at the Huron site than on \nthe Ottawa site for all sampling depths. Fall aspen fine-root biomass had a significant \nsoil X treatment interaction. Soil compaction decreased the fine root biomass on the \nOttawa site. However, soil compaction tended to increase aspen fine-root biomass on \nthe Huron site. The fine-root data from the Ottawa site indicate that the effects of soil \ncompaction were still noticeable seven years after its application. Significant \ndifferences (p <0.05) among the mean growing-season foliar nitrogen concentrations \nwithin the treatments were observed at the Ottawa site. This was not noticeable in the \nfoliage collected just prior to senescence. The results indicate that any effects the \ncompaction treatments have had on tree nutrition have begun to disappear.
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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 ».