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The development of cultivated landscapes under the influence of food production has decisively shaped the composition and appearance of West African savannas as present today. With trees and shrubs forming an important constituent of such landscapes, and its composition characterizing different types of land-use, anthracology is a tool particularly well suited to trace developments and changes through human exploitation of the landscape. Within the West African savanna belts, regions shaped by prolonged annual floods, such as the Middle Senegal Valley, the Inland Niger Delta and the Chad Basin, offer particular ecological preconditions for land-use. We present here a charcoal study for the Chad Basin of northeast Nigeria, demonstrating the special development of a cultivated landscape in an alluvial context. Charcoal samples from stratified Late Stone Age and Iron Age sites within the southwestern Chad Basin, Nigeria were analyzed. Main focus is on the site Mege, spanning more than 2500 years of occupation history. The results are supplemented with and compared to data from other, earlier as well as contemporary sites, in similar or slightly different environments and representing different settlement types, in order to discern general trends. The results illustrate the exploitation of woody vegetation mainly from the clay soils. This is in stark contrast to the results from other regions within the savanna belt, where the vegetation on sandy soils was preferentially exploited for fuel wood. The vegetation changes evidenced through the charcoal assemblages are attributed to reduced flooding as a consequence of falling lake levels during the Late Holocene. Parklands, typical cultivated landscapes of West African savannas, are invisible in the charcoal spectra, and fallow species and useful trees are rarely present. We postulate that the ecological conditions of the floodplain environment have decisively paved a different, less obvious trajectory of cultivated landscape development between 2000 BC and AD 1500 and that the cultivated landscapes present in the region today largely result from the increasing human impact of the last 500 years.

Archaeobotanical evidence from archaeological sites in northeast Burkina Faso dating to the first and second millennia AD has provided a useful insight into crop cultivation and the development of the West African savanna landscape. Nitrogen isotopic analysis of charred pearl millet grains from the same sites now provides the first opportunity to investigate how increased crop production and permanence of cultivated fields related to the intensity of household waste/manure application. Nitrogen isotope values of pearl millet grains increased during the first two millennia AD, indicating an intensification of manuring that would have enabled soil to stay fertile for longer, reducing the agricultural footprint of shifting cultivation. This may have been advantageous as population and settlement density increased, thereby increasing competition over land. The intensity of manure application in the second millennium AD at sites close to the Mare d’Oursi suggests that manure was likely sourced from outside the farming settlements, from livestock herded by nomadic pastoralists who would have been drawn to the mare for water. This is rare evidence for specialisation of sedentary farmers and pastoralists, demonstrating how the novel combination of fruit/seed, charcoal, faunal and isotopic evidence used in this study can enrich our knowledge of past lifeways in West Africa.

Many societal and environmental changes occurred between the 2nd millennium BC and the middle of the 2nd millennium AD in western Africa. Key amongst these were changes in land use due to the spread and development of agricultural strategies, which may have had widespread consequences for the climate, hydrology, biodiversity, and ecosystem services of the region. Quantification of these land-use influences and potential feedbacks between human and natural systems is controversial, however, in part because the archaeological and historical record is highly fragmented in time and space. To improve our understanding of how humans contributed to the development of African landscapes, we developed an atlas of land-use practices in western Africa for nine time-windows over the period 1800 BC–AD 1500. The maps are based on a broad synthesis of archaeological, archaeobotanical, archaeozoological, historical, linguistic, genetic, and ethnographic data, and present land use in 12 basic categories. The main differences between categories is the relative reliance on, and variety of, domesticated plant and animal species utilized, and the energy invested in cultivating or keeping them. The maps highlight the irregular and frequently non-linear trajectory of land-use change in the prehistory of western Africa. Representing an original attempt to produce rigorous spatial synthesis from diverse sources, the atlas will be useful for a range of studies of human–environment interactions in the past, and highlight major spatial and temporal gaps in data that may guide future field studies., Open access funding provided by Max Planck Society. This work was supported by Grants to JOK from the European Research Council (COEVOLVE, 313797), the Swiss National Science Foundation (ACACIA, CR10I2_146314), and the Fondation Herbette (2016-2-E-16). JMR was funded by the Funds for Research Training in Industry and Agriculture (National Funds for Scientific Research, Belgium) and the Leopold II Funds (Belgium). Data were also acquired in the framework of the Era-Net BiodivERsA CoForChange project, funded by the French National Research Agency and National Environment Research Council (UK).

Pits are common features at sites of the Nok Culture, which is known for its masterful terracotta sculptures and for early iron metallurgy in sub-Saharan Africa. If pits are stratified and well-dated, contained archaeological charcoal may serve as a proxy for vegetation change—especially for changes mediated by human impact. Recent investigations into charcoal samples from several pits at Pangwari, a Nok site that has been—not necessarily continuously—in use during the last 1.5 millennia BC, revealed that the taphonomy of these assemblages is not as straightforward as expected. Find distribution analysis documents that regularly only the lowermost parts of the pits are still in their original state. Later re-working of the original pit filling, erosion, and recent illicit digging for terracotta figurines challenge the interpretation of the charcoal data. Moreover, the distribution of 14C dates and of potsherds assigned to different pottery groups, as well as differences in the charcoal assemblages of some pits, hint towards divergent backfill histories. Some pits seem to have been refilled quite quickly, possibly even in a single event, while other pits might have remained open for a longer time. Additionally, pits likely were reused in later phases and the infill became mixed. For charcoal analysis, it is hence crucial to consider the backfill history of each pit based on the archaeological evidence.

Agriculture was introduced into the Central African rainforest from the drier West African savanna, in concert with a major climatic change that amplified seasonality just after 2500 BP. The savanna crop pearl millet (Pennisetum glaucum), dated to 2400–2200 BP, could only be cultivated due to the development of a distinct dry season. Increasing seasonality and the replacement of mature forests by pioneer formations is indicated by Trema orientalis in the pollen diagram of Nyabessan after 2400 BP. However, charcoal data do not point to the existence of savannas in South Cameroon during this period, but rather to a mosaic of mature and pioneer forests. The early rainforest farmers combined the cultivation of pearl millet with the exploitation of wild oil-containing tree fruits, such as oil palm and Canarium. The existence of pioneer formations that can be easily cut favoured the establishment of shifting cultivation. The archaeobotanical finds fit into a linguistic scenario of West-Bantu speakers making the cultivation of pearl millet one of their food production strategies before expanding further to the South. The reconstructed inherited pearl millet vocabulary for the early phases of Bantu language history provides strong circumstantial evidence for an overlap of the major stages of the Bantu expansion with the dispersal of food production.

Identification of archaeological or soil charcoal in a species-rich biome, such as the Central African rainforest, is challenging because of the large number of woody taxa with similar and overlapping wood anatomical features. Valid environmental or archaeological interpretations can only derive from reliable and transparent identifications that allow comparison of and referencing between different charcoal assemblages. The identification of 30 archaeological charcoal types from the site Dibamba in southern Cameroon serves as a starting point for a discussion on classification and naming. These 30 types are fully documented and illustrated in the Supplementary Online Material (SOM). The discussion underlines the basics of “good practice” of charcoal identification in a speciesrich tropical environment. The value of differential diagnosis is stressed, as is the importance of leaving identification levels on higher taxonomic level if necessary. We argue that the level of identification must be reflected in the name of the charcoal type. Names of charcoal types are written in small capitals to clearly distinguish them from botanical taxa with which they are not necessarily identical. The Dibamba charcoal assemblage offers the first and so far unique possibility to directly comprehend human impact on the structure and composition of West Central African rainforest over the last 3000 years. The paleoenvironmental significance of the results presented here will be subject of a forthcoming publication.

Bayon et al . (Reports, 9 March 2012, p. 1219) interpreted unusually high aluminum-potassium ratio values in an Atlantic sediment core as indicating anthropogenic deforestation around 2500 years before the present (B.P.). We argue that there is no terrestrial evidence for forest destruction by humans and that the third millennium B.P. rainforest crisis can be clearly attributed mostly to climatic change.

In a paper by Garcin et al. in PNAS (1), it is assumed that a sharp increase in settlement activities in the Central African rainforest during the first millennium BC caused widespread deforestation between 2,600 and 2,020 cal y BP (the late Holocene rainforest crisis or LHRC) (2, 3). Archaeology was only marginally used in this new study by means of a newly compiled radiocarbon database containing 1,202 14C dates from 460 sites in Central Africa covering the past 10,500 y. Those dates must be critically evaluated, as not all of them are relevant for assessing the human factor in the LHRC. Not only the quantity of … [↵][1]1To whom correspondence should be addressed. Email: bernardolivier.clist{at}ugent.be. [1]: #xref-corresp-1-1