Nothofagus forest dynamics and palaeoenvironmental variations during the mid and late Holocene, in southwest Patagonia
| Autor: | Gonzalo David Sottile, Sonia L. Fontana, Marcos Emanuel Echeverria, Maria Virginia Mancini |
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| Rok vydání: | 2014 |
| Předmět: |
Archeology
MID- LATE HOLOCENE Ciencias de la Tierra y relacionadas con el Medio Ambiente southwest Patagonia mid–late Holocene Holocene Earth-Surface Processes Nothofagus Global and Planetary Change Ecology Fire regime Forest dynamics biology palaeoenvironmental reconstruction Paleontology Westerlies 15. Life on land biology.organism_classification pollen analysis 13. Climate action Climatology Physical geography fire regime Meteorología y Ciencias Atmosféricas CIENCIAS NATURALES Y EXACTAS Geology |
| Popis: | Southern Patagonia intersects the core of the Southern Westerlies, providing a unique opportunity for palaeo-reconstructions and the implication of past wind variations. There is a strong link between the strength of the westerlies and precipitation, which impacts vegetation communities. The palaeoenvironmental changes that occurred since the middle Holocene to present days are reconstructed from a peat record recovered in Peninsula Avellaneda (50°15′57″S; 72°50′33″W). Interpretations are based on pollen, charcoal and sediment analyses. Closed Nothofagus forest together with low fire activity characterized the region during the period c. 5500–3500 cal. yr BP, related to an increased in precipitation through an intensification of the westerlies. After 3500 cal. yr BP, shrub and grass communities became dominant at the expense of Nothofagus forest, suggesting a climatic shift to dry conditions, as a result of weaker westerlies. This patchy forest-steppe vegetation has favoured the occurrence of fire events. Subsequently, Nothofagus forest recovered for a short period between 2000 and 400 cal. yr BP. Then, major vegetation changes took place with the re-establishment of an open landscape. The calculated moisture balance index allowed us to hypothesize about the relationship between westerlies fluctuation and El Niño Southern Oscillation (ENSO) anomalies during the mid and late Holocene. Fil: Echeverria, Marcos Emanuel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Cs.exactas y Naturales. Departamento de Biología. Laboratorio de Paleoecología y Palinologia; Argentina Fil: Sottile, Gonzalo David. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Cs.exactas y Naturales. Departamento de Biología. Laboratorio de Paleoecología y Palinologia; Argentina Fil: Mancini, Maria Virginia. Universidad Nacional de Mar del Plata. Facultad de Cs.exactas y Naturales. Departamento de Biología. Laboratorio de Paleoecología y Palinologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Fontana, Sonia Leonor. University Of Göttingen; Alemania |
| Databáze: | OpenAIRE |
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