Vegetation and fire history during the last 18,000 cal yr B.P. in Southern Patagonia: Mallin Pollux, Coyhaique, Province Aisen (45°4130"S, 71°50'30" W, 640 m elevation)

dc.contributor.authorMarkgraf, Veraen_AU
dc.contributor.authorWhitlock, Cathyen_AU
dc.contributor.authorHaberle, Simonen_AU
dc.date.accessioned2015-12-07T22:44:24Z
dc.date.issued2007
dc.date.updated2015-12-07T11:24:24Z
dc.description.abstractTo better understand the climate, vegetation and fire history of southern South America since the last deglaciation, sediment characteristics, diatoms, pollen, microscopic and macroscopic charcoal and magnetic susceptibility were analyzed in a 14-m long sediment core from a closed basin fen at Lago Pollux, Aisén Province, southern Chile (45°41′30″ S lat, 71°50′30″ W long, 640 m elev.). Sediment characteristics, absence of diatoms and scarce pollen suggest that before 18,000 cal yr BP, glacier meltwaters were feeding the small basin when local glaciers were at their maximum position. From 18,000 to ca. 14,000 cal yr BP, the site was a shallow productive pond surrounded by a sparse scrub-steppe and accompanied some fire activity. This period was markedly drier, but warmer than before. By 14,000 cal yr BP, the fen developed and a species-rich steppe expanded suggesting a moderate increase in effective moisture and temperature. High fluctuations of terrestrial and aquatic pollen taxa occur between 14,000 and 11,000 cal yr BP, attesting to climate variability at this time. Between 11,000 and 7500 cal yr BP, Nothofagus steppe-woodland developed and fire activity was very high, with several large local events. Precipitation must have increased, but most likely summers were drier than today with high frequency of convective storms. After 7500 cal yr BP present-day closed Nothofagus forest became established, and fire activity decreased, suggesting establishment of present-day equable precipitation regime. The forest was more open between 4000 and 1500 cal yr BP than before and shrubs or trees grew on the fen. Forest clearance and grazing only began in the mid-20th century. Both in terms of timing and character of past changes in vegetation and fire activity, the record from M. Pollux takes an intermediate position between records from high southern latitudes, versus those from mid-latitudes, indicating the different latitudinal expression of the southern westerly storm tracks during the last 18,000 cal yr BP.
dc.identifier.issn0031-0182
dc.identifier.urihttp://hdl.handle.net/1885/25167
dc.publisherElsevier
dc.sourcePalaeogeography, Palaeoclimatology, Palaeoecology
dc.subjectKeywords: climate variation; core analysis; diatom; fire history; last deglaciation; paleoclimate; palynology; vegetation history; Patagonia; South America; Bacillariophyta; Nothofagus 18,000 years paleoclimate; Southern Patagonia; Vegetation and fire histories
dc.titleVegetation and fire history during the last 18,000 cal yr B.P. in Southern Patagonia: Mallin Pollux, Coyhaique, Province Aisen (45°4130"S, 71°50'30" W, 640 m elevation)
dc.typeJournal article
local.bibliographicCitation.issue2007
local.bibliographicCitation.lastpage507
local.bibliographicCitation.startpage492
local.contributor.affiliationMarkgraf, Vera, University of Colorado
local.contributor.affiliationWhitlock, Cathy, Montana State University
local.contributor.affiliationHaberle, Simon, College of Asia and the Pacific, ANU
local.contributor.authoremailu3399096@anu.edu.au
local.contributor.authoruidHaberle, Simon, u3399096
local.description.embargo2037-12-31
local.description.notesImported from ARIES
local.identifier.absfor060206 - Palaeoecology
local.identifier.ariespublicationu9305715xPUB36
local.identifier.citationvolume254
local.identifier.doi10.1016/j.palaeo.2007.07.008
local.identifier.scopusID2-s2.0-34548855032
local.identifier.uidSubmittedByu9305715
local.type.statusPublished Version

Downloads

Original bundle

Now showing 1 - 1 of 1
No Thumbnail Available
Name:
01_Markgraf_Vegetation_and_fire_history_2007.pdf
Size:
1006.27 KB
Format:
Adobe Portable Document Format