Revisiting past savanna environments: Pollen analysis of the Colbyn wetland on the southern African central plateau

Abstract

A high-resolution, radiocarbon dated, pollen sequence of the ecotone between the Grassland and Savanna Biomes, was extracted from a 2.5 m peat core at the Colbyn wetland in South Africa. The lithology indicates transitions between organic sediment, clay, and well-preserved peat layers. The pollen and micro-charcoal records suggest interactions between the seasonal climate, burning and possible human and other disturbance. The vegetation development over the last 4000 cal yr BP is compared with chronologically parallel pollen sequences from the nearby Moreleta River and Rietvlei Dam sequences. The study, that can be correlated with wider regional isotopic records of the region, shows drier conditions c. 3800 to 3400 cal yr BP, and around 800 cal yr BP, and a wetter phase at Colbyn c. 3000–1500 cal yr BP. • Well dated late Holocene peat sequence in urban area of Southern Africa. • Peat development vegetation, burning and climate change prior to current settlement. • Improved environmental reconstruction on edge of the highveld plateau. • Palynological contribution to history of grassland-savanna ecotone.