Clim. Past, 9, 223–241, 2013 www.clim-past.net/9/223/2013/ Climate doi:10.5194/cp-9-223-2013 of the Past © Author(s) 2013. CC Attribution 3.0 License. Palynological evidence for gradual vegetation and climate changes during the African Humid Period termination at 13◦ N from a Mega-Lake Chad sedimentary sequence P. G. C. Amaral1, A. Vincens1, J. Guiot1, G. Buchet1, P. Deschamps1, J.-C. Doumnang2, and F. Sylvestre1 1CEREGE, Aix-Marseille Universite,´ CNRS, IRD, College` de France, Europoleˆ Mediterran´ een´ de l’Arbois, BP 80, 13545 Aix-en-Provence cedex 4, France 2Departement´ des Sciences de la Terre, Universite´ de N’Djamena (UNDT) BP 1027 N’Djamena, Chad Correspondence to: P. G. C. Amaral (
[email protected]) Received: 16 May 2012 – Published in Clim. Past Discuss.: 18 June 2012 Revised: 18 December 2012 – Accepted: 19 December 2012 – Published: 29 January 2013 Abstract. Located at the transition between the Saharan and period. However, we cannot rule out that an increase of Sahelian zones, at the center of one of the largest endorheic the Chari–Logone inputs into the Mega-Lake Chad might basins, Lake Chad is ideally located to record regional envi- have also contributed to control the abundance of these taxa. ronmental changes that occurred in the past. However, until Changes in the structure and floristic composition of the veg- now, no Holocene archive was directly cored in this lake. etation towards more open and drier formations occurred In this paper, we present pollen data from the first sed- after ca. 6050 cal yr BP, following a decrease in mean Pann imentary sequence collected in Lake Chad (13◦ N; 14◦ E; estimates to approximately 600 (−230/+600) mm.