Can phytoliths provide an insight into past vegetation of the Middle Kalahari palaeolakes during the late Quaternary?

African archaeology without frontiers: papers from the 2014 PanAfrican Archaeological Association Congress

“…The Mosu Escarpment consists of a series of bluffs, hills and plateaus stretching east-west for about 50 km just south of Sowa Pan, in north-east Botswana. The escarpment itself is part of the system of strandlines surrounding the entire Makgadikgadi Pans that resulted from shore formation during the existence of Palaeolake Makgadikgadi (Burrough et al 2009(Burrough et al , 2012. The Mosu bluffs are about 55 m tall from the perspective of the lowlands to their immediate north.…”

Comment on “Burrough, S.E., Breman, E., and Dodd, C., 2012. Can phytoliths provide an insight into past vegetation of the Middle Kalahari paleolakes during the late Quaternary? Journal of Arid Environments 82, 156–164”

“…This is a comment on the article of Burrough et al (2012) in which they present a palaeoclimatic reconstruction based on phytolith assemblages from sandy shoreline deposits in the Makgadikgadi Basin, Botswana. While this work highlights a potentially important paleoenvironmental archive in a notably data-poor region, there are several fundamental short-comings in the Burrough et al work in terms of the calibration of their findings with plant distributions and ecology.…”

“…Not recognising these limitations in their article, the authors apply palaeoenvironmental indices that are regionally inappropriate, and which we argue in turn render their paleoenvironmental interpretations invalid. With no regionally specific reference collection being established, it may be the misidentification of phytolith morphotypes that has created the paradox that is posed by Burrough et al Burrough et al (2012) present a reconstruction of past vegetation change as a response to palaeoclimatic variability based on phytolith assemblages from sandy shoreline deposits in the Makgadikgadi Basin, Botswana. The data presented show diverse assemblages of phytoliths that indicate that the study of these microfossils has potential for the reconstruction past environmental conditions in the region.…”

“…1. Map of southern Africa, including major drainage systems and potential fluvial transport vectors to the sites described by Burrough et al (2012). The shaded area indicates those regions where the mean temperature of the wet season is below 22 C (data from Hijmans et al, 2005), the cross-over threshold for C 3 grasses.…”