Late Holocene settlement and vegetation history of the Sahel in Burkina Faso
The Oursi pollen profile
The starting point of the research conducted by the SFB 268 in Burkina Faso was the pollen profile from the seasonal Lake Oursi which seemed to indicate the beginning of agriculture in this area around 1000 BC. In the 1999s large-scale excavations were conducted on Final Stone Age dune sites and Iron Age settlement mounds, and a quite different trajectory of the settlement history emerged. In the second millennium BC, hunter-gatherer populations were living in northern Burkina Faso, and the first signs of domesticated crops only appear towards the end of this period. After 1000 BC, there is almost no evidence for the presence of humans. Only around BC/AD sedentary farming populations appear on the scene. Both distinct ruptures in the settlement history have no equivalent in the pollen profile, and the interpretation was revised accordingly. The changes in the profile around 1000 BC are probably due to increasing aridity and aggradation of the lake.
Final Stone Age
In the second millennium BC, people living in northern Burkina Faso had a foraging economy with some elements of plant cultivation. Hunting, fishing and the exploitation of wild fruits were the major subsistence activities, but also some small-scale cultivation of pearl millet (Pennisetum glaucum). Maybe they also had domesticated animals, but there is no direct evidence. The sites are small and seem to have been seasonally, but repeatedly, inhabited. The influence of the Final stone age populations on the vegetation cannot be detected so far in the palaeoenvironmental archives.
Towards the end of the second millennium BC, lower precipitation and longer dry seasons resulted in the seasonal desiccation of the formerly permanent lakes in northern Burkina Faso. It is conceivable that only small mobile groups could cope with the environmental challenges: There are almost no archaeological sites dating to the first millennium BC.Iron Age
From 0 BC/AD new cultural groups appear, now sedentary and equipped with the knowledge of iron technology. Numerous large settlement mounds yielded millions of pottery sherds, iron objects, adornments, charred fruits seeds and charcoal. Based on the shape and decorations of the potsherds, the Iron Age can be sub-divided into three phases. At first, the typical pottery features are grooves at or near the rim and incised decorations on the vessel body. The Middle Iron Age starts at around 500 AD with the appearance of polished comb impressions. From the 11th century AD, new vessel forms such as bottles with lid, sieving vessels or three-legged vessels are added; they are characteristic of the Late Iron Age.
The subsistence of the Iron Age people was mainly based on agriculture. Mixed farming included pearl millet, legumes and roselle (Hibiscus sabdariffa). Useful wild trees were protected and their fruits complemented the diet. Cattle and small livestock were also part of the agricultural system. In the course of 1500 years, a cultural landscape emerged as a consequence of extensive land-use: fields and fallows with useful trees and easily burgeoning shrubs substituted the natural vegetation around the settlements on the dunes. For the middle and late Iron Age, there is evidence for increasing impact of pastoralism.
Information about the social life during the Iron age comes from the excavations of the cemeteries at Kissi, dated mainly between the first and the seventh century AD. Numerous grave goods indicate a hierarchical society and the high status of warriors.
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Trade contacts
From the 4th century AD onwards, there are increasing signs of far-reaching trade contacts. Contacts existed on different levels: regional, between several West African regions, and maybe also long-distance contacts as far as Asia. Imported goods include stones beads from the Sahara, glass and carnelian beads from the Middle East and kauri snails from the Indian Ocean. Precious brass and bronze jewellery objects point to contacts with North Africa. Sorghum and water melon probably also reached northern Burkina Faso as trade goods; later they were cultivated in the region.
It seems that the climate remained more or less stable during the period when the settlement mounds were flourishing. The mounds were abondoned in the 14th century AD, maybe due to political developments in the Niger bend or to climatic change.
Selected publications
Ballouche, A. & K. Neumann (1995): A new contribution to the Holocene vegetation history of the West African Sahel: pollen from Oursi, Burkina Faso and charcoal from three sites in northeast Nigeria. - Vegetation History and Archaeobotany 4: 31-39.
Breunig, P. & K. Neumann (2002): From hunters and gatherers to food producers: new archaeological and archaeobotanical evidence from the West African Sahel. - In: F. Hassan (ed.): Ecological Change and Food Security in Africa’s Later Prehistory: 123-155. New York (Kluwer Academic / Plenum Publishers).
Höhn, A. & K. Neumann (2011, in press): Tilling the dunes - Shifting cultivation and the development of a cultural landscape in the Sahel of Burkina Faso, West Africa. Quaternary International.
Höhn, A., S. Kahlheber & M. Hallier-von Czerniewicz (2004): Den frühen Bauern auf der Spur – Siedlungs- und Vegetationsgeschichte der Region Oursi (Burkina Faso). – In: Albert, K.-D., D. Löhr & K. Neumann (eds.): Mensch und Natur in Westafrika, 221-288. Abschlussbuch des Sonderforschungsbereichs 268. Weinheim (Wiley - VCH).
Kahlheber, S. & K. Neumann (eds., 2001) Man and Environment in the West African Sahel - an Interdisciplinary Approach. Berichte des Sonderforschungsbereichs 268, 17, Frankfurt a. Main.
Kahlheber, S. & K. Neumann (2007): The development of plant cultivation in semi-arid west Africa. - In: Denham, T. P., Iriarte, J. & Vrydaghs, L. (eds.): Rethinking Agriculture: Archaeological and Ethnoarchaeological Perspectives: 320-346. One World Archaeology 51. Walnut Creek (Left Coast Press).
Linseele, V. (2010): Did specialized pastoralism develop differently in Africa than in the Near East? An example from the West African Sahel. – Journal of World Prehistory 23(2), 43-77.
Magnavita, S., M. Hallier, C. Pelzer, S. Kahlheber & V. Linseele (2002): Nobles, guerriers, paysans. Une nécropole de l’Age de Fer et son emplacement dans l’Oudalan pré- et protohistorique. – Berichte zur Allgemeinen und Vergleichenden Archäologie 22, 21-64.
Neumann, K., Kahlheber, S. & Uebel, D. (1998): Remains of woody plants from Saouga, a medieval West African village. - Vegetation History and Archaeobotany 7(2): 57-77.
Vogelsang, R., K.-D. Albert & S. Kahlheber (1999): Le sable savant: Les cordons dunaires sahéliens au Burkina Faso comme archives archéologiques et paléoécologiques pour l’Holocène. – Sahara 11, 51-68.
Dissertations
Höhn, A. (2005): Zur eisenzeitlichen Entwicklung der Kulturlandschaft im Sahel von Burkina Faso. Untersuchungen von archäologischen Holzkohlen. Dissertation. Goethe University, Frankfurt. http://publikationen.ub.uni-frankfurt.de/volltexte/2005/2253/
Kahlheber, S. (2004): Perlhirse und Baobab - Archäobotanische Untersuchungen im Norden Burkina Fasos. Dissertation. Goethe University, Frankfurt. http://publikationen.ub.uni-frankfurt.de/volltexte/2005/561/
Linseele, V. (2007): Archaeofaunal remains from the past 4000 years in Sahelian West Africa. Dissertation. Catholic University Leuven. BAR International Series 1658. Cambridge Monographs in African Archaeology 70, Cambridge.
Magnavita, S. (2006): 1500 Jahre am Mare de Kissi. Eine Fallstudie zur Besiedlungsgeschichte im Sahel von Burkina Faso. Dissertation. Goethe University, Frankfurt.
von Czerniewicz, M. (2002): Studien zur Chronologie der Eisenzeit in der Sahel-Zone von Burkina Faso/Westafrika. Dissertation. Goethe University, Frankfurt. http://publikationen.ub.uni-frankfurt.de/volltexte/2004/373/
Diploma / M.A. theses
Diethelm, B. (2002): Topfbestattungen der Sudan-Zone Westfarikas. M.A. thesis.
Höhn, A. (1997): Vergleichende Untersuchungen der Holzstruktur ausgewählter Mimosoideae und Caesalpinioideae (Leguminosae) Westafrikas. Diploma thesis.
Kahlheber, S. (1995): Vergleichende anatomische und morphologische Untersuchungen ausgewählter Paniceenfrüchte. Diploma thesis.
Kühltrunk, P. (2000): Typologische und taphonomische Keramikanalyse des steinzeitlichen Fundplatzes Tin-Akoff im Norden Burkina Fasos. M.A. thesis.
Magnavita, S. (1999): Die eisenzeitliche Nekropole von Kissi, Prov. Oudalan, Burkina Faso. M.A. thesis.
Morczinek, I. (1995): Diatomeen aus dem Mare d’Oursi – Ein Beitrag zur holozänen Paläoökologie des westafrikanischen Sahel. Diploma thesis.
