Phytoliths from Middle Stone Age habitats in the Mozambican Rift (105e29 ka) Julio Mercader a, * , Tim Bennett a , Chris Esselmont b , Steven Simpson a , Dale Walde a a Department of Archaeology, University of Calgary, Alberta T2N 1N4, Canada b Department of Sociology, University of Calgary, Alberta T2N 1N4, Canada article info Article history: Received 8 June 2012 Accepted 22 October 2012 Available online xxx Keywords: Africa Mozambique Malawi/Niassa Rift Woodland Late Pleistocene abstract The detection of areas suitable for hominins during late Pleistocene drought intervals is currently a priority for Middle Stone Age research. Predicting the location of populations and dispersal pathways through the East African Rift System during the last glacial phase is a challenging task due to scarce direct archaeo-vegetation data. We present a Mozambican phytolith record spanning 105e29 ka and argue for the necessity and utility of using local plant microbotanical data from archaeological sites to understand the past environments in which early modern humans lived. We assess biome structure, spatial vari- ability, and compare phytolith-based to lacustrine environmental reconstructions to conclude that dense wooded landscapes dominated the area over much of the last glacial phase. Archaeological and botanical data suggest the hypothesis of a palaeodispersal along a montane woodland archipelago that could have attracted hominin settlement and facilitated dispersals through an inland bridge that connected southern, central and East Africa, and the two branches of the East African Rift System. Ó 2013 Elsevier Ltd. All rights reserved. Introduction The influence of climatic change on human evolution has been well-documented for decades. This is particularly clear in the southern East African Rift System (EARS) where late Pleistocene climate records from lake cores provide evidence of desiccation and loss of tree cover (Cohen et al., 2007; Scholz et al., 2007 , 2011; Beuning et al., 2011; Stone et al., 2011). Extreme environmental deterioration is said to cause demographic bottlenecks and the abandonment of the interior in favor of the coast (Carto et al., 2009). However, synchronizing lacustrine datasets with human ecology is not without problems (Blaauw, 2012) because drilling data have a different scope, are insensitive to micro-environmental diversity, and do not speak to human exploitation of econiches. Moreover, the mechanisms controlling high climatic variability and habitat heterogeneity remain unresolved (Debusk, 1998; Johnson et al., 2002; Garcin et al., 2006; Brown et al., 2007; Vincens et al., 2007; Finch et al., 2009; Beuning et al., 2011; Schefuß et al., 2011) and contrasting landscapes co-existed locally (Blome et al., 2012) at the basin level. Therefore, the detection of areas suitable for hom- inins in inland regions during drought intervals remains a research priority. We examine the effects of landscape diversity on the occupation of the northern Mozambican Rift Valley in the southern African interior during the severe climate fluctuations of the late Pleisto- cene. Our research area spans the Niassa graben flank. Its highland zone belongs to the wet woodland ‘archipelago’ scattered from Chimanimani (Zimbabwe) to Uluguru-Mlanje (Tanzania and Malawi, respectively) (White, 1978). This area was implicated in phylogeographical vicariance between the temperate and tropical zones at times of climate change (Blome et al., 2012). It sustains remnant forests fed by underground and surface water, higher precipitation, and cooler temperatures than surrounding lowlands (Munishi and Shear, 2005; Timberlake et al., 2006). Its vegetation has attracted naturalists since the early days of botanical explora- tion (White, 1978; Lovett et al., 1988; Burrows and Willis, 2005; Timberlake et al., 2006) because mesic taxa, species richness, and relict endemics suggest rather moist conditions (see also Garcin et al., 2006; Finch et al., 2009) and several refugia during the late Pleistocene (Lorenzen et al., 2012). The aim of this paper is to reconstruct ecological preference and settlement of Niassa during the late and final Middle Stone Age (MSA) through biogenic silica from archaeological sediments. Phytoliths shed light on three long- term aspects of local ecology: vegetation structure, spatial hetero- geneity, and habitat shift (Miller et al., 2012). Regional phytoliths have been demonstrated to pick up changes in the woodland/ grassland interface, tree cover, and relative abundance of grass clades linked to specific moisture conditions (Alexandre et al., 1997; * Corresponding author. E-mail address: mercader@ucalgary.ca (J. Mercader). Contents lists available at SciVerse ScienceDirect Journal of Human Evolution journal homepage: www.elsevier.com/locate/jhevol 0047-2484/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jhevol.2012.10.013 Journal of Human Evolution xxx (2013) 1e9 Please cite this article in press as: Mercader, J., et al., Phytoliths from Middle Stone Age habitats in the Mozambican Rift (105e29 ka), Journal of Human Evolution (2013), http://dx.doi.org/10.1016/j.jhevol.2012.10.013