Microscopic charcoals in ocean sediments off Africa track past fire intensity from the continent - Réseau télédétection INRAE Accéder directement au contenu
Article Dans Une Revue Communications Earth & Environment Année : 2023

Microscopic charcoals in ocean sediments off Africa track past fire intensity from the continent

Bernard Dennielou
Germain Bayon
Xavier Crosta

Résumé

Abstract 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.
Fichier principal
Vignette du fichier
s43247-023-00800-x.pdf (2.03 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-04082024 , version 1 (28-04-2023)

Licence

Paternité

Identifiants

Citer

Aritina Haliuc, Anne-Laure Daniau, Florent Mouillot, Wentao Chen, Bérangère Leys, et al.. Microscopic charcoals in ocean sediments off Africa track past fire intensity from the continent. Communications Earth & Environment, 2023, 4 (1), pp.133. ⟨10.1038/s43247-023-00800-x⟩. ⟨hal-04082024⟩
234 Consultations
19 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More