A Dissertation Submitted to the Faculty of SCience
University of the Witwatersrand. Johannesburg
for the Degree of Master of Science / This study of the impact of elephants, Loxodonta africana (Blumenbach), in private
reserves ln South Africa's lowveld region aimed to determine the sizes and species
of woody plants most often affected by elephants and the proportion and severity of
elephant impact on the marula tree Sclerocarya birrea. The study was conducted in
three parts: vegetation quadrats in areas where elephants had been foraging, direct
observation of the feeding behaviour of hand-raised elephants, and transects to
sample S. birrea across the study areas. To distinguish preferences, the frequency
of elephant impact on each species was compared with the frequency with which it
was encountered by the elephants. In the vegetation quadrats, I found that
uprooting and leaf stripping were infrequent in all sizes of stems, Main stem
breakage affected stems lese than 30 cm in diameter whereas branch breakage and
bark stripping increased with increasing size. Favoured species were Combretum
collinum, Acacia gerrardii, Albizia harveyl sclerocarya birrea, Dalbergia
metenoxyton, and Pterocarpus rotundifolius. Notable among neglected species
were Acacia toriifis, Tettnmelle prunioides, and Terminalia sericea which are
favoured food items for elephants elsewhere. Other common species which were
not selected by elephants were Acacia exuvielis, Cassine transvaalensis, Ehretia
emoene, Euclea netalensis and Securinega virosa. Behavioural observation
revealed that hand-raised elephants favoured eating Sclerocarya birrea, Combretum
epiculeium, and Acacla nigrescens. The elephants stripped bark from A. nigrescens
and S. birrea. Assessment of rnarula trees revealed that elephant impact killed
fewer than 2% of stems during the preceding season. Fewer than 24% of trees had
current season breakage or bark removal. Main stem breakage Was found in stems
smaller than 40 ern in diameter. Ring barking was concentrated on the larger size
classes, while the smaller size classes escaped any detectable form of elephant
impact. / Andrew Chakane 2018
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/24905 |
| Date | January 1997 |
| Creators | Gadd, Michelle |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
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