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| Titel |
Fire history in western Patagonia from paired tree-ring fire-scar and charcoal records |
| VerfasserIn |
A. Holz, S. Haberle, T. T. Veblen, R. Pol-Holz, J. Southon |
| 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 ; 8, no. 2 ; Nr. 8, no. 2 (2012-03-09), S.451-466 |
| Datensatznummer |
250005462
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| Publikation (Nr.) |
 copernicus.org/cp-8-451-2012.pdf |
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| Zusammenfassung |
| Fire history reconstructions are typically based on tree ages and tree-ring
fire scars or on charcoal in sedimentary records from lakes or bogs, but
rarely on both. In this study of fire history in western Patagonia (47–48° S)
in southern South America (SSA) we compared three sedimentary charcoal
records collected in bogs with tree-ring fire-scar data collected at 13
nearby sample sites. We examined the temporal and spatial correspondence
between the two fire proxies and also compared them to published charcoal
records from distant sites in SSA, and with published proxy reconstructions
of regional climate variability and large-scale climate modes. Two of our
three charcoal records record fire activity for the last 4 ka yr and one for
the last 11 ka yr. For the last ca. 400 yr, charcoal accumulation peaks
tend to coincide with high fire activity in the tree-ring fire scar records,
but the charcoal records failed to detect some of the fire activity recorded
by tree rings. Potentially, this discrepancy reflects low-severity fires
that burn in herbaceous and other fine fuels without depositing charcoal in
the sedimentary record. Periods of high fire activity tended to be
synchronous across sample areas, across proxy types, and with proxy records
of regional climatic variability as well as major climate drivers. Fire
activity throughout the Holocene in western Patagonia has responded to
regional climate variation affecting a broad region of southern South
America that is teleconnected to both tropical- and high-latitude climate
drivers-El Niño-Southern Oscillation and the Southern Annular Mode. An
early Holocene peak in fire activity pre-dates any known human presence in
our study area, and consequently implicates lightning as the ignition
source. In contrast, the increased fire activity during the 20th century,
which was concomitantly recorded by charcoal from all the sampled bogs and
at all fire-scar sample sites, is attributed to human-set fires and is
outside the range of variability characteristic of these ecosystems over
many centuries and probably millennia. |
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