Identifying the woody resources of Diepkloof Rock Shelter (South Africa) using scanning electron microscopy of the MSA wood charcoal assemblages

This article presents the results of the anatomical identification of wood charcoal from pre-Still Bay, Still Bay and Howiesons Poort assemblages at Diepkloof Rock Shelter (South Africa) using scanning electron microscopy. In the earliest phases, with pre-Still Bay stone tools, the charcoal shows a predominance of Afromontane forest taxa, some riverine woodland species, mesic thicket and proteoid fynbos vegetation. With a change in lithic technology in Still Bay contexts, the balance of Afromontane and thicket taxa shifts towards favouring the latter. A more diverse array of proteoid fynbos species emerges, and there is evidence for the use of plants from the local wetlands of the Verlorenvlei. In Howiesons Poort contexts, typified by a different lithic technology, the charcoal shows some Afromontane forest persisting, but the overwhelming change is towards greater species diversity, with the woody taxa being increasingly representative of thicket and shrubland. Some of the fynbos and thicket species are typical of vegetational communities which inhabit well-drained soils, rocky or dry locations at the present day. More wetland plants from the Verlorenvlei were selected for use. The range of taxa in pre-Still Bay, Still Bay and Howiesons Poort contexts and the diversity of their preferred habitats (modelled on present-day recorded distributions) cannot be interpreted in a simplistic manner to reflect a unilinear change in climatic or soil moisture conditions. Whilst such factors may have played a significant part and contributed to some or all of the taxa having very different phytogeographical distributions compared to their modern counterparts (as at the nearby Elands Bay Cave), it is also necessary to consider to what extent people might have collected these diverse woody resources from a mosaic of vegetational communities, some local, some far away. These scenarios are not mutually exclusive and future collaborative work, which aims to include detailed local mapping of all woody taxa present in the sequence, will be crucial for presenting a resolved palaeoenvironmental and phytogeographical reconstruction through time. (C) 2013 Elsevier Ltd. All rights reserved.