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| 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... |
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| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00181/29235/27640.pdf |
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| Urrego, Dunia H.; Hooghiemstra, Henry; Rama-corredor, Oscar; Martrat, Belen; Grimalt, Joan O.; Thompson, Lonnie; Bush, Mark B.; Gonzalez-carranza, Zaire; Hanselman, Jennifer; Valencia, Bryan; Velasquez-ruiz, Cesar. |
| We compare eight pollen records reflecting climatic and environmental change from northern and southern sites in the tropical Andes. Our analysis focuses on the last 30 000 years, with particular emphasis on the Pleistocene to Holocene transition. We explore ecological grouping and downcore ordination results as two approaches for extracting environmental variability from pollen records. We also use the records of aquatic and shoreline vegetation as markers for lake level fluctuations and moisture availability. Our analysis focuses on the signature of millennial-scale climate variability in the tropical Andes, in particular Heinrich stadials (HS) and Greenland interstadials (GI). The pollen records show an overall warming trend during the... |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00421/53285/54277.pdf |
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| Daniau, Anne-laure; Desprat, Stéphanie; Aleman, Julie C.; Bremond, Laurent; Davis, Basil; Fletcher, William; Marlon, Jennifer R.; Marquer, Laurent; Montade, Vincent; Morales-molino, César; Naughton, Filipa; Rius, Damien; Urrego, Dunia H.. |
| The Earth has experienced large changes in global and regional climates over the past one million years. Understanding processes and feedbacks that control those past environmental changes is of great interest for better understanding the nature, direction and magnitude of current climate change, its effect on life, and on the physical, biological and chemical processes and ecosystem services important for human well-being. Microfossils from terrestrial plants – pollen, microcharcoal and phytoliths – preserved in terrestrial and marine sedimentary archives are particularly useful tools to document changes in vegetation, fire and land climate. They are well-preserved in a variety of depositional environments and provide quantitative reconstructions of past... |
| Tipo: Text |
Palavras-chave: Pollen; Microcharcoal; Phytolith; Terrestrial and marine sedimentary archives; Vegetation; Fire; Middle Pleistocene; Last glacial period; Holocene. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00485/59705/83610.pdf |
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