Title:

Late Holocene Vegetation Change in North-East Namibia - Examining vegetation dynamics considering human land-use and environmental change

Author(s):
Publication Year:
2019
Abstract:

Local communities of north-east Namibia rely on natural resources for their livelihoods which has played and continues to play an influential role in the savanna ecosystem, although the degree to which people have impacted the regional vegetation is unknown. Long-term vegetation history can aid in conservation decisions by providing context to the current vegetation. Unfortunately, late-Holocene paleorecords of vegetation and climate change are virtually non-existent for north-east Namibia. Paleoecology proxies can determine long-term vegetation dynamics, particularly tree density, and determine the extent of natural and anthropogenic forcing on these changes. Three radiocarbon dated sediment cores were analysed using loss on ignition and mass spectrometry to determine organic and inorganic carbon content, and δ13C values, respectively. A constrained hierarchical clustering (CONISS) was applied to these proxies to define distinct environmental periods. Two of the three cores suggest a more modern increase in tree density while the third core shows a rapid decline in tree density. Two of the cores suggest wetter periods between ca. 1000 – 500 BP and from ca. 300 BP. The oldest core spans the duration of the Holocene epoch and shows changes in hydrologic patterns and vegetation. There is evidence for two sites that past human resource harvesting has influenced the state of the modern ecosystems within the last 400 years, which has led to at least one of the sites showcasing typical ‘bush encroachment’ (i.e. invasion of woody plants). Additional proxies, such as pollen, fungal spores, and charcoal, would need to be taken into consideration in order to further explore the interaction between humans and vegetation in the region, and establish a comprehensive management plan for conserving vegetation in the region.

Place:
University of Cape Town
Type:
BSc Thesis
Item Type:
Thesis
Language:
en

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