Brenden Pienaar

MSc candidate in Ecology, University of the Witwatersrand, Johannesburg. Supervisors: Prof. Ed Witkowski (WITS) , Dr Dave Thompson (SAEON Ndlovu) and Prof. Trevor Hill (UKZN)

Brenden completed his BTech (Nature Conservation) at Cape Peninsula University of Technology in 2007.

The biogepgraphy of Brachystegia woodland relicts in southern Africa.

Description: Pollen records from the genus Brachystegia suggest that miombo woodland has experienced rapid range retraction (~450 km) from its southern-most distributional limit over the past 6000 years. This abrupt biological response created two isolated (by ~200 km) and incomparable relicts at the trailing population edge in north-east South Africa and south-central Mozambique. These changes in miombo population dynamics may have been triggered by minor natural shifts in temperature and moisture regimes. Should this be correct, it suggests that Brachystegia spiciformis (the dominant component of miombo in southern Africa) is likely to be especially responsive to present and future anthropogenic climate change. This rare situation offers a unique opportunity to investigate climatic determinants of range shift at the trailing edge of a savanna species and (using relicts a laboratories) how climatic constraint drives change in miombo population composition and structure.