Notice bibliographique
Résumé
Soil CO2 emissions or soil respiration (Rs) data were measured at an eastern white pine forest (Pinus strobus L.) planted in 1939 as monoculture stands north of Lake Erie in southern Ontario, Canada. The forest site is part of the Turkey Point Observatory and has been associated with AmeriFlux and global Fluxnet initiatives, where it is known as CA-TP4. The forest is dominated (>82%) by eastern white pine, while other tree species include 11% balsam fir (Abies balsamea L. Mill) and species native to the hardwood forests of North American Eastern Temperate Forest Ecoregion, including 4% Oak (Quercus velutina L., Q. alba L.), 2 % Red Maple (Acer rubrum L.) and some wild black cherry trees (Prunus serotina Ehrh). The forest was thinned in 1983 and winter of 2012, where one-third of trees were randomly removed. Soil CO2 efflux was measured using an automated non-steady state chamber system developed by the University of British Columbia in a 50 m × 50 m area located 100 m north from the eddy covariance flux tower at the site from June 2008 to October 2018. Initially four chambers were installed. One measured heterotrophic respiration (FRT1) in the trenched plot whereby live tree roots were removed from surrounding area and other three as controls. chambers and measured total soil CO2 efflux (FS: FS1, FS2, and FS22). One of the control chambers (FS22) was altered in May 2009 to measure the contributions from the mineral-soil horizon (FLR) to total soil respiration, by removing the litter layer. In May 2009, two more control chambers (FS3 and FS4) were added to the chamber system to measure total soil respiration. Finally, in May 2010, two additional chambers were installed, one as a control (FS5) and an additional chamber to measure heterotrophic respiration (FRT2); increasing the total number of chambers in the chamber system to eight. In total, five chambers were measuring total soil CO2 efflux, two chambers measured heterotrophic soil CO2 efflux and one chamber measured contributions from the mineral-soil horizon. Each chamber consisted of a PVC collar and a chamber lid that fit onto the collar. The collars were inserted approximately 2 to 4 cm into the ground. The chamber lid consisted of a transparent plastic dome fixed to a metal frame. Each chamber closed individually for a one-minute interval, where the CO2 concentration was sampled and measured by an infrared gas analyzer (model LI-840, Li-COR Inc.). Measurements were cycled through the eight collars for a total of three cycles per half-hour period. Each half-hour average consisted of three, minute-long CO2 concentration measurements per chamber. One half-hourly value was produced for each collar by averaging the three measurements taken during that half-hour. The measurement chambers remained open when not taking measurements. Throughout the growing season, any vegetation growth was removed from inside the collars to eliminate potential photosynthesis effects. Chamber 1: Reference plot (then converted to litterless in May 8, 2009) Chamber 2: Reference plot Chamber 3: Heterotrophic plot (trenched at the time of instalation in 2008 to exclude live roots). Chamber 4: Drought plot (90% rainfall exclusion from 1 April to 3 July, 2009 in a 20m x 20m plot) Chamber 5: Reference plot (installed in May 2009) Chamber 6: Drought plot (installed in May 2009) (90% rainfall exclusion from 1 April to 3 July, 2009 in a 20m x 20m plot). Chamber 7: Reference plot (installed in May 2010 ) Chamber 8: Reference plot (converted to heterotrophic in May 2010 by trenching and excluding live roots) Tree density is 413 (321) tree per ha, Leaf Area Index is 8.5 (5.3), tree heigh 23.4 (22.9) m, and diamter at breat heigh is 39 (37.2) m. Numbers in paranthesis show vales after 2012 thinning. Topography in the area is predominantly flat with occasional 0.5-3.0% undulating slopes. The soil at the site is well drained with a low water holding capacity and classified as brunisolic grey-brown luvisols in the Canadian System of Soil Classification and is composed of ~98% sand. The climate in the region is cool temperate with a 30-year mean annual temperature of 8.0 °C and mean annual precipitation of 1036 mm.
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 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,002 | 0,003 |
| Études des sciences et des technologies | 0,001 | 0,000 |
| Communication savante | 0,001 | 0,001 |
| Science ouverte | 0,002 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,008 | 0,004 |
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 ».