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dc.contributor.advisorDu Preez, P. J.
dc.contributor.advisorBredenkamp, G. J.
dc.contributor.authorDingaan, Mamokete Nthabiseng Vivian
dc.date.accessioned2017-02-08T08:28:07Z
dc.date.available2017-02-08T08:28:07Z
dc.date.issued2008-05
dc.identifier.urihttp://hdl.handle.net/11660/5575
dc.description.abstractEnglish: Acacia karroo is an ecologically important and one of the most widespread species in South Africa. There has been an opinion that Acacia karroo-dominated vegetation, especially that along river banks, should be classified under one class, and that a comprehensive syntaxonomic review of Acacia karroo-dominated syntaxa is needed. The present study was hence initiated with the aim of providing more insight into the syntaxonomic status of all the previously described Acacia karroo syntaxa. A total of 1 553 relevés and 2 006 species from 60 phytosociological studies were hierarchically classified according to Braun-Blanquet procedures. TURBOVEG was used for the input, processing, and presentation of phytosociological data. MEGATAB was used to first construct the phytosociological and synoptic tables. TWINSPAN was applied to the floristic data as a first approximation, after which Braun-Blanquet procedures were used to refine the classification. The result of the classification process was a suggested Acacia karroo Class differentiated into the following six orders: i) Cyperus longus – Asparagus laricinus Order associated with rivers and streams in the northern Free State. The species composition of this vegetation type indicates that it could represent a transformed Hemarthria altissima Class (Du Prezz & Bredenkamp 1991) brought about by degradation and disturbance, and the subsequent encroachment by Acacia karroo. ii) Achyranthes aspera – Diospyros lycioides Order represents riparian vegetation of the northern, central, and southern Free State. It mostly occurs on the well developed banks along the rivers, streams, and drainage lines, but can also be found on clayey soils on the floodplains adjacent to the rivers. iii) Felicia filifolia – Tragus koelerioides Order represents false karoid vegetation of the mountains, hills, ridges and valleys of the Graaff-Reinet and Cradock areas in the Eastern Cape, and Beaufort West in the Western Cape. iv) Rhus ciliata – Rhus lancea Order represents false karroid vegetation of the southern Free State and is mainly associated with undulating plains and gentle slopes. v) Acacia mellifera - Eragrostis lehmanniana Order represents vegetation of the Kalahari thornveld found in northwestern Free State, northeastern Northern Cape, as well as southern and central North-West. vi) Teucrium trifidum – Themeda triandra Order is found in northern Free State, in the eastern part of North-West, and also in eastern and western Gauteng, as well as in western Mpumalanga. It occurs in kloofs and sheltered valleys, and also on mountain slopes It is also encountered on bottomlands and footslopes with deep clayey soils. vii) Acacietalia karroo (Eckhardt, Van Rooyen & Bredenkamp 1997) represents vegetation of the crests, slopes and footslopes of hills in central-northern KwaZulu-Natal but it is also encountered in the incised river valleys in southern KwaZulu-Natal. The Acacia karroo Class is further differentiated into ten sub-orders, forty alliances, 110 associations, and 39 sub-associations. All communities were described and ecologically interpreted.en_ZA
dc.description.abstractAfrikaans: Acacia karroo is ekologies belangrik en een van die wyd verspreidste boomsoorte in Suid-Afrika. ‘n Algemene opvatting bestaan dat Acacia karroo-gedomineerde plantegroei, veral op rivieroewers en vloedvlaktes geklassifiseer behoort te word in een sintaksonomiese klas, en dat ‘n omvattende sintaksonomiese oorsig van Acacia karroo-gedomineerde sintaksa nodig is. Die huidige studie is geinisieer met die doel om meer insig op die sintaksonomiese status van al die beskryfde Acacia karroo sintaksa te gee. ‘n Totaal van 1 553 relevés and 2 006 spesies uit 60 fitososiologiese studies is hierargies geklassifiseer volgens Braun-Blanquet prosedures. TURBOVEG is gebruik om die data vas te vang en die fitososiologiese data te proseseer. MEGATAB is gebruik om die fitososiologiese en sinoptiese tabelle te konstrueer. TWINSPAN is toegepas om die floristiese data aanvanklik te klassifiseer en daarna is dit deur middel van Braun-Blanquet prosedures verfyn to finale sinoptiese tabelle. Die resultaat van die klassifikasie proses word as die Acacia karroo Klas voorgestel en is gedifferensieer in die volgende ses ordes: i) Cyperus longus – Asparagus laricinus Orde geassosieer met riviere en strome in die noordelike Vrystaat. Die spesiesamestelling van hierdie sintakson dui daarop dat dit ‘n getransformeerde Hemarthria altissima Klass (Du Prezz & Bredenkamp 1991) kan verteenwoordig. Die verandering is moontlike deur agteruitgang en versteuring veroorsaak wat gelei het tot indringing deur Acacia karroo. ii) Achyranthes aspera – Diospyros lycioides Orde verteenwoordig oewer plantegroei in die noordelike, sentrale en suidelike Vrystaat. Dit kom hoofsaaklik op goed ontwikkelde rivier- en spruitoewers voor maar kan ook op klei gronde op vloedvlaktes langs riviere gevind word. iii) Felicia filifolia – Tragus koelerioides Orde verteenwoordig vals karoo-plantegroei in berge, heuwels en valleie in die karoo streke naby Graaff-Reinet en Cradock in die OosKaap asook in die Beaufort Wes omgewing in die WesKaap. iv) Rhus ciliata – Rhus lancea Orde verteenwoordig vals karoo-plantegroei in die suidelike Vrystaat en is veral met golwende vlaktes en platterige hellings geassosieer. v) Acacia mellifera - Eragrostis lehmanniana Orde verteenwoordig plantegroei van die Kalahari doringveld in die noord-westelike Vrystaat, noordoos NoordKaap asook die sentrale deel van die Noord-Wes Provinsie. vi) Teucrium trifidum – Themeda triandra Orde kom in die noord Vrystaat asook die oostelike dele van Noord-Wes, die westelike en oostelike dele van Gauteng sowel as in die westelike Mpumalanga voor. Dit kom in klowe en beskutte valleie asook op berghellings voor. Verder word dit ook gevind op laagliggende dele en voethellings waar diep klei-gronde voorkom. vii) Acacietalia karroo (Eckhardt, Van Rooyen & Bredenkamp 1997) verteenwoordig plantegroei op kruine, hellings en voethellings van heuwels in sentraal en noord KwaZulu-Natal. Dit kom verder ook voor in die diep rivier valleie in suidelike KwaZulu-Natal. Die Acacia karroo Klass word verder onderverdeel in tien sub-ordes, veertig alliansies, 110 assosiasies en 39 sub-assosiasies. Al die syntaksa word beskryf en ekologies geinterpreteer.af
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.subjectThesis (Ph.D. (Botany (Plant Sciences))--University of the Free State, 2008en_ZA
dc.subjectAcacia karrooen_ZA
dc.subjectAllianceen_ZA
dc.subjectAssociationen_ZA
dc.subjectBraun-Blanquet methoden_ZA
dc.subjectClassen_ZA
dc.subjectCommunityen_ZA
dc.subjectMEGATABen_ZA
dc.subjectOrderen_ZA
dc.subjectSynoptic tableen_ZA
dc.subjectTURBOVEGen_ZA
dc.subjectTWINSPANen_ZA
dc.subjectAcacia -- Africa, Southern -- Identificationen_ZA
dc.subjectAcacia -- Africa, Southernen_ZA
dc.titleInterpretation of the Acacia karroo class, southern Africaen_ZA
dc.typeThesisen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


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