A 40,000-year record of vegetation and fire history from the Tate Vondo region, Northeastern Southpansberg, South Africa.
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Date
2014
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Abstract
Records from the Quaternary period are used to confirm possible inferred climatic changes,
reveal the responses of species to these changes, and serve as an archive against which
modern environmental dynamics can be assessed. Fueled by a need to understand current
climatic changes, the call for palaeoclimatic research in the southern African subregion has
become more compelling. In southern Africa, such research has been largely restricted to
springs and swamps as the subregion lacks natural lakes, with some exception of a few
coastal lakes such as Lake Sibaya and Lake Eteza. Due to the arid and semi-arid landscapes
which prevail in southern Africa, there is a paucity of suitable sedimentary deposits in the
region. The highly organic peat deposit of Mutale Wetland, situated in the Tate Vondo region
of the northeastern Soutpansberg presents an ideal opportunity for conducting
palaeoenvironmental research. The Mutale Wetland contains relatively old sediments dating
back to >30,000 cal years BP, placing this record within the late Quaternary period.
Palaeoenvironmental techniques including radiocarbon, pollen and charcoal analyses were
applied to produce a palaeoenvironmental reconstruction for Tate Vondo. A 302 cm
sedimentary core was extracted from the Mutale Wetland. Detailed analyses show that prior
to ca. 34,000 cal yr BP, conditions were fairly warm and dry. This is inferred from a
dominance of open grassland vegetation. An expansion of Podocarpus forests together with
an increase in fynbos elements suggest a shift to cool, subhumid conditions during the LGM.
Cooler conditions persisted until ca. 12,000 cal yr BP. Thereafter, a climatic amelioration
was experienced. The appearance of low charcoal concentrations throughout the late
Pleistocene suggests that fire was infrequent. Between ca. 4000 – 1500 cal yr BP, conditions
became warmer and drier, inferred from the development of arid savanna vegetation. The
sharp increase in charcoal after ca. 4000 cal yr BP, broadly coinciding with the arrival of the
first agriculturalists in the area, has implications for the history of human occupation in the
Soutpansberg rather than shifts in climate. The succession from savanna to fynbos vegetation
together with expanded forests implies a return to cool and moist conditions from ca. 1500 –
400 cal yr BP. Arid savanna persists from ca. 400 to the present, implying warmer and drier
conditions towards the present day. Furthermore, from ca. 400 cal yr BP, the pollen and
charcoal record indicate that the majority of recent changes in vegetation have been driven by
anthropogenic activity. This record has contributed to an improved understanding of late
Quaternary changes in climate, vegetation history and human impact in the northeastern
Soutpansberg.
Description
Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2014.
Keywords
Climatic changes--Africa, Southern., Paleogeography--Holocene., Paleogeography--Africa, Southern--Quaternary., Geomorphology--Africa, Southern--Geography., Theses--Geography.