Haliuc A., Daniau A. L., Mouillot Florent, Chen Wentao, Leys B., David V., Hanquiez V., Dennielou B., Schefuss E., Bayon G., Crosta X. (2023). Microscopic charcoals in ocean sediments off Africa track past fire intensity from the continent. Communications Earth and Environment, 4 (1), p. 133 [11 p.].
Titre du document
Microscopic charcoals in ocean sediments off Africa track past fire intensity from the continent
Année de publication
2023
Auteurs
Haliuc A., Daniau A. L., Mouillot Florent, Chen Wentao, Leys B., David V., Hanquiez V., Dennielou B., Schefuss E., Bayon G., Crosta X.
Source
Communications Earth and Environment, 2023,
4 (1), p. 133 [11 p.]
Large grassland and open savannah fires occurred during humid periods of the Holocene in subtropical Africa and contributed to increased carbon dioxide in the atmosphere, according to the concentration and morphotype of microcharcoals in marine sediments off Africa Fires in Africa account for more than half of global fire-carbon emissions but the long-term evolution of fire activity and its link to global climate change remains elusive. Paleofire records provide descriptive information about fire changes through time, going beyond the range of satellite observations, although fire regime characteristics are challenging to reconstruct. To address this conceptual gap, we report here the abundance and morphometric data for a large set of microscopic charcoal samples (n = 128) recovered from surface ocean sediments offshore Africa. We show that in subtropical Southern Africa, large and intense fires prevailing in open savanna-grassland ecosystems produce a high abundance of small and elongated microcharcoal particles. In contrast, in the forest ecosystems of equatorial and tropical regions of western and central Africa, low-intensity fires dominate, producing low amounts of squared microcharcoal particles. Microcharcoal concentration and morphotype in marine sediment records off Africa are thus indicative of fire regime characteristics. Applied to down-core marine charcoal records, these findings reveal that at orbital time-scale intense and large, open grassland-savanna fires occurred during wet periods in the sub-tropical areas. A strong contribution of fire carbon emissions during periods of precession and summer insolation maxima in the geological record is thus expected.
Plan de classement
Sciences du milieu [021]
;
Géologie et formations superficielles [064]
;
Etudes, transformation, conservation du milieu naturel [082]
Description Géographique
AFRIQUE
Localisation
Fonds IRD [F B010087669]
Identifiant IRD
fdi:010087669
