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| Titel |
Environmental and climatic changes in central Chilean Patagonia since the Late Glacial (Mallín El Embudo, 44° S) |
| VerfasserIn |
M. E. de Porras, A. Maldonado, F. A. Quintana, A. Martel-Cea, O. Reyes, C. Mendez |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 10, no. 3 ; Nr. 10, no. 3 (2014-05-28), S.1063-1078 |
| Datensatznummer |
250116978
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| Publikation (Nr.) |
 copernicus.org/cp-10-1063-2014.pdf |
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| Zusammenfassung |
| Multi-millennial environmental and climatic changes in central Chilean
Patagonia (44–49° S) during the Last Glacial–Interglacial cycle
have been of particular interest as changes in the position and strength of
the southern westerlies are the major forcing factor conditioning the
environmental dynamics. Recent attempts to reconstruct regional environmental
and climatic signals from central Chilean Patagonia reveal some discrepancies
and unclear issues among the records. This paper presents the 13 ka pollen
and charcoal records from Mallín El Embudo (44° 40' S, 71°
42' W) located in the deciduous Nothofagus forest in the middle
Río Cisnes valley. The paper aims to (1) establish the timing and magnitude
of local vegetation changes and fire activity since the Late Glacial and (2)
integrate these results at the regional scale in order to discuss the
discrepancies and depict the environmental and climatic dynamics in central
Chilean Patagonia since the Late Glacial. Open landscapes dominated by
grasses associated with scattered Nothofagus forest patches
dominated the middle Río Cisnes valley between 13 and 11.2 ka suggesting
low effective moisture but also indicating that landscape configuration after
glacial retreat was still ongoing. At 11.2 ka, the sudden development of an
open and quite dynamic Nothofagus forest probably associated with
the synchronous high fire activity occurred, suggesting a rise in effective
moisture associated with dry summers. Since 9.5 ka, the record reflects the
presence of a closed Nothofagus forest related to higher effective
moisture conditions than before combined with moderate dry summers that may
have triggered a high frequency of low-magnitude crown fires that did not
severely affect the forest. The forest experienced a slight canopy opening
after 5.7 ka, probably due to slightly drier conditions than before followed
by a sudden change to open forest conditions around 4.2 ka associated with
fire and volcanic disturbances. Around 2 ka, the recovery of a closed
Nothofagus forest related to slightly wetter conditions (similar to
present) occurred and persisted under highly variable climatic conditions up
to 0.1 ka when massive forest burning and logging due to European
settlements occurred. Central Chilean Patagonian climatic and environmental
changes at millennial–centennial timescales since the Late Glacial were
driven by changes in the southern westerlies latitudinal position and/or
intensity, but during the late Holocene fire, volcanism and humans arose as
forces contributing to environmental dynamics. |
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