| Titre | Plant community ecology and climate on a volcanic landscape during the Early Eocene Climatic Optimum: McAbee fossil beds, British Columbia, Canada |
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| Auteur | Lowe, A J; Greenwood, D R; West, C K; Galloway, J M ; Sudermann, M; Reihgelt, T |
| Source | Palaeogeography, Palaeoclimatology, Palaeoecology vol. 511, 2018 p. 433-448, https://doi.org/10.1016/j.palaeo.2018.09.010 |
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| Année | 2018 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20180199 |
| Éditeur | Elsevier |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1016/j.palaeo.2018.09.010 |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Province | Colombie-Britannique |
| Région | McAbee |
| Lat/Long OENS | -121.2500 -121.2167 51.3500 51.3167 |
| Sujets | paléobotanique; paléoécologie; paléoclimatologie; Eocene; plantes fossiles; schistes; écosystèmes; Diversité biologique; Changement climatique; Nature et environnement; paléontologie; Sciences et
technologie; géologie de l'environnement; Cénozoïque |
| Illustrations | cartes de localisation; échelles stratigraphiques; photographies; tableaux; figures; diagrammes de distribution |
| Programme | GEM2 : La géocartographie de l'énergie et des minéraux TransGEM |
| Diffusé | 2018 12 15 |
| Résumé | (disponible en anglais seulement)
The McAbee Fossil Beds, in south-central British Columbia, Canada, provide a record of forest ecosystems within a volcanically-active, upland landscape during
the Early Eocene Climatic Optimum (EECO). To assess plant community ecology and climate within this environment, palynology and census-style macrofossil collections were investigated from two shale horizons separated in time by likely 103-104 years.
An ensemble of leaf physiognomic estimates indicates a persistent warm (mean annual temperature [MAT]?10-12 °C) and mesic (mean annual precipitation?1000 mm?yr?1) climate between the horizons. The plant community was similar in both horizons,
comprising angiosperms (e.g., Ulmus, Fagus, Alnus, Betula, and Carya) and gymnosperms (e.g., Metasequoia, Pinus, Picea, and Larix). Plant diversity and the distribution of dicot leaf mass per area (MA) values were consistent between the two horizons,
despite intervals of varying tuff thickness and frequency between the horizons. Differences in macrofossil abundances of Ulmus, Fagus, and Pinus, and a lack of such differences in their respective pollen abundances might be explained by local patch
dynamics, influenced by spatial heterogeneity resulting from topographic diversity and disturbance. MA estimates suggest dicots were predominately deciduous, and the distribution of MA is similar to a modern forest in Panama influenced by seasonal
precipitation. The diversity of dicots at McAbee, despite relatively lower mean annual temperatures, is comparable to fossil plant quarries of similar volume from early Eocene sites in Patagonia (e.g., Laguna del Hunco) and the Denver Basin with
relatively warmer MATs (17-25 °C). This is best explained by a combination of predominately frostfree winters, high productivity, and an abiotic environment characterized by spatial heterogeneity and high rates of change. The sampled paleofloras of
this study showcase an EECO plant community, likely representing an ecological solution to volcanic disturbance over millennial time scales. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Cette étude présente les résultats d'une évaluation systématique des restes macrofloraux de plantes, de pollens et de spores conservés dans les
premiers lits fossiles de l'Eocène McAbee, au centre-sud de la Colombie-Britannique. L'étude fournit un nouvel aperçu du fonctionnement de l'écosystème terrestre dans un monde de serre. |
| GEOSCAN ID | 311215 |
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