Late Quaternary vegetation history and climatic change in the eastern Orange Free State, South Africa

Sixty-nine pollen spectra from three sites with alluvial and swamp deposits and 12 spectra representing the modern vegetation in the eastern Orange Free State and Drakensberg areas, provide evidence about the Late Quaternary environmental history of Clarens. Factor analysis is used to compare pollen data between sites. Stepwise changes in the vegetation at Clarens are indicated, relating to changes in climatic variables during the Late Pleistocene and Holocene. The earliest palaeo-environmental indications recorded immediately north of Clarens are of humid grassland with strong fynbos and swampy conditions ca. 23 000years BP, followed by progressively cooler, drier conditions ca. 22 600 to 19 000years BP. Grass in the vegetation became more prominent between ca. 18 000 and 17 000years BP. Shrubby grassland with some fynbos elements occurred in the Little Caledon Basin ca. 13 000years BP, under slightly warmer conditions which were relatively moist, probably also during winters. Podocarpus forests developed in distant mountain ravines but together with fynbos elements, declined before 10 700years BP, possibly under the influence of slightly warmer conditions and growing seasonal contrasts. The Holocene record is incomplete, starting apparently with grassland indications for warm conditions, and ending with subhumid, markedly seasonal conditions and local swamp development as found along the Little Caledon River