|
|
|
|
|
Daniau, Anne-laure; Goni, Maria Fernanda Sanchez; Martinez, Philippe; Urrego, Dunia H.; Bout-roumazeilles, Viviane; Desprat, Stephanie; Marlon, Jennifer R.. |
Although grassland and savanna occupy only a quarter of the world's vegetation, burning in these ecosystems accounts for roughly half the global carbon emissions from fire. However, the processes that govern changes in grassland burning are poorly understood, particularly on time scales beyond satellite records. We analyzed microcharcoal, sediments, and geochemistry in a high-resolution marine sediment core off Namibia to identify the processes that have controlled biomass burning in southern African grassland ecosystems under large, multimillennial-scale climate changes. Six fire cycles occurred during the past 170,000 y in southern Africa that correspond both in timing and magnitude to the precessional forcing of north-south shifts in the Intertropical... |
Tipo: Text |
|
Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00181/29235/27640.pdf |
| |
|
|
Eynaud, Frederique; De Abreu, Lucia; Voelker, Antje; Schoenfeld, Joachim; Salgueiro, Emilia; Turon, Jean-louis; Penaud, Aurelie; Toucanne, Samuel; Naughton, Filipa; Goni, Maria Fernanda Sanchez; Malaize, Bruno; Cacho, Isabel. |
This paper documents the migration of the Polar Front (PF) over the Iberian margin during some of the cold climatic extremes of the last 45 ka. It is based on a compilation of robust and coherent paleohydrological proxies obtained from eleven cores distributed between 36 and 42 degrees N. Planktonic delta O-18 (Globigerina bulloides), ice-rafted detritus concentrations, and the relative abundance of the polar foraminifera Neogloboquadrina pachyderma sinistral were used to track the PF position. These three data sets, compared from core to core, show a consistent evolution of the sea surface paleohydrology along the Iberian margin over the last 45 ka. We focused on five time slices representative of cold periods under distinct paleoenvironmental forcings:... |
Tipo: Text |
Palavras-chave: Polar Front; LGM; Heinrich events. |
Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00218/32909/31415.pdf |
| |
|
| |
|
|
Daniau, Anne-laure; D'Errico, Francesco; Goni, Maria Fernanda Sanchez. |
Background: It has been proposed that a greater control and more extensive use of fire was one of the behavioral innovations that emerged in Africa among early Modern Humans, favouring their spread throughout the world and determining their eventual evolutionary success. We would expect, if extensive fire use for ecosystem management were a component of the modern human technical and cognitive package, as suggested for Australia, to find major disturbances in the natural biomass burning variability associated with the colonisation of Europe by Modern Humans. Methodology/Principal Findings: Analyses of microcharcoal preserved in two deep-sea cores located off Iberia and France were used to reconstruct changes in biomass burning between 70 and 10 kyr cal BP.... |
Tipo: Text |
|
Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00231/34242/32652.pdf |
| |
|
|
|