Charcoal insights on the vegetation, climate and subsistence patterns at Wonderwerk Cave

Wonderwerk Cave is one of the most important archaeological sites in central southern Africa as it preserves multiple indicators of past environments, climates and human behavior. The cave has the potential to provide important palaeoenvironmental and palaeoethnobotanical information that can be applied to the less archeologically understood central southern African region. This study provides the vegetation and climate context of the interior southern African region during 2.3–0.5 ka BP by using charcoal from strata 2b and 3a of Wonderwerk Cave. The study also provides possible human-plant interactions during this time. A total of 90 charcoal fragments were studied under a microscope, their taxonomy determined, and the modern distribution of nearest living relatives utilized to determine the environmental conditions of the area in the past. A second method was applied by associating the physiognomic features of wood charcoal with the habitat. Both methods indicate a dry environment dominated by shrubs and small trees such as Ozoroa paniculosa, Searsia lancea, Olea europaea subsp. africana, Ziziphus mucronata, Grewia flava, Tarchonanthus parvicapitulatus, Diospyros austro-africana, Euclea undulata, Ehretia sp and Vitex rehmanii. Wet environment-tolerant species such as Ochna serrulata and Olinia ventosa might suggest fluctuations in climatic conditions or the presence of microhabitats such as streams or underground water. The analyses overall indicate the environment 2.3-0.5 ka BP was open and arid but slightly wetter than the area presently.