Woody vegetation change over more than 30 years in the interior duneveld of the Kalahari Gemsbok National Park

Keywords: bush encroachment, conservation area, Kgalagadi Transfrontier Park, southern Kalahari, Vachellia erioloba,, vegetation dynamics, watering point


Background and objectives: Long-term studies of woody plants in South Africa are scarce. This study, initiated in the late 1970s, therefore aids understanding of vegetation dynamics in the southern Kalahari by investigating woody vegetation
change at and away from a watering point.
Methods: At three sites, all woody individuals were counted by species in plots 0.5 or 1 ha in size. Seedlings were noted separately from the >0.2 m group of individuals.
Results: Vachellia erioloba and shrub density decreased over time whereas dwarf shrub species’ numbers fluctuated markedly. Additionally, no increase in density of known bush encroaching species (e.g. Grewia flava, Rhigozum trichotomum
and Senegalia mellifera) was found in this large conservation area.
Discussion and conclusion: The changes in density of the woody species seem to point to the importance of particular rainfall patterns or sequences of events over different years that are responsible for these changes in the southern Kalahari, and the evident lack of bush encroachment in this conservation area supports the notion that bush encroachment in arid savannas is driven primarily by land-use practices and not by elevated carbon dioxide levels that are sometimes provided as cause for encroachment.

Author Biographies

H. van der Merwe, South African Environmental Observation Network (SAEON)

SAEON, Arid Lands Node, Kimberley, South Africa

H. Bezuidenhout, South African National Parks (SANParks); Applied Behavioural Ecology and Ecosystem Research Unit, University of South Africa.

South African National Parks (SANParks), Scientific Services, Kimberley, South Africa;

Applied Behavioural Ecology and Ecosystem Research Unit, University of South Africa.

J. du P. Bothma, Centre for Wildlife Management, University of Pretoria

Centre for Wildlife Management, University of Pretoria, Pretoria, South Africa.


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How to Cite
van der Merwe, H., van Rooyen, N., Bezuidenhout, H., du P. Bothma, J., & van Rooyen, M. (2020). Woody vegetation change over more than 30 years in the interior duneveld of the Kalahari Gemsbok National Park. Bothalia, African Biodiversity & Conservation, 50(1). Retrieved from http://abcjournal.org/index.php/BothaliaABC/article/view/114
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