Thesis (MSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Non-native species are recognized as a major component of global environmental
change. Their ecological impacts are numerous and include the alteration of whole ecosystem
processes as well as the loss of native biodiversity. As such, understanding the processes that
drive the invasion of non-native species is essential for the control and management thereof.
Numerous research approaches have been used to provide insight on the history and ecology
of non-native species invasions. However, recent approaches employing molecular
techniques have greatly helped in solving taxonomic issues associated with some of these
species; identifying sources of invasions; and shedding light on colonization dynamics.
Lantana camara, a globally invasive and highly variable species complex, is one of the
most notorious plant invaders in South Africa. The species has been associated with negative
impacts in agricultural areas, decreased invertebrate diversity, livestock mortality, and where
it occurs along riparian areas- decreased water quality and obstruction to accessing water
sources. This project aimed to review L. camara invasions in South Africa and to unravel
patterns of spread in L. camara along the Sabie-Sand catchment in South Africa’s flagship
protected area, the Kruger National Park, using a molecular approach.
The findings of the first part of the study highlight that L. camara has successfully
spread across South Africa with only four known introduction events, and this can be
attributed to the species’ broad ecological tolerance, its use in the horticultural industry, and a
variety of dispersal vectors (birds, humans and rivers). Furthermore, although sale of the
species is prohibited in the country, it will continue to spread naturally and also has the
potential to expand its distribution under changing climate scenarios. The second part of the
study highlights that spread along the Sabie-Sand catchment is primarily river-driven and that
the Sand tributary is the invasion source in the system. Because the Sand tributary originates
outside the Kruger National Park, and only a small portion is under park management, the
implications for spread are important. / AFRIKAANSE OPSOMMING: Nie-inheemse spesies word erken as 'n belangrike komponent van die globale
omgewing verandering. Hulle ekologiese impak is talle en sluit in die verandering van
ekosisteem prosesse asook die verlies van inheemse biodiversiteit. As sodanig, die begrip van
die prosesse wat lei tot die inval van 'n nie-inheemse spesies is noodsaaklik vir die beheer en
bestuur daarvan. Talle navorsingsbenaderings is gebruik om insig te gee oor die geskiedenis
en ekologie van nie-inheemse spesies invalle. Onlangse benaderings soos die gebruik van
molekulêre tegnieke, help in die oplossing van taksonomiese kwessies wat verband hou met
'n paar van hierdie spesies,in die identifisering van bronne van invalle, en om lig te werp op
die kolonisasie dinamika.
Lantana camara, 'n wêreldwye indringende en spesie kompleks, is een van die mees
berugte plantindringer in Suid-Afrika. Die spesie is geassosieer met negatiewe gevolge in
landbou gebiede, afgeneem ongewerwelde diversiteit, vee mortaliteit, en waar dit voorkom
saam oewer gebiede - afgeneem kwaliteit van die water en obstruksie tot waterbronne.
Hierdie projek is daarop gemik om om L. camara invalle in Suid-Afrika te hersien en patrone
van verspreiding te ontrafel in L. camara langs die Sabie-Sand-opvanggebied in Suid-Afrika
se vlagskip beskermde gebied, die Kruger Nasionale Park, met behulp van 'n molekulêre
benadering.
Die bevindinge van die eerste deel van die studie wys dat L. camara het suksesvol
versprei oor die hele Suid-Afrika met slegs vier bekende inleiding gebeure, en dit kan
toegeskryf word aan die spesie se breë ekologiese verdraagsaamheid, die gebruik daarvan in
die hortologie bedryf, en 'n verskeidenheid van die verspreiding vektore (voëls, mens en
riviere). Verder, hoewel die verkoop van die spesie in die land verbied word, sal dit natuurlik
voortgaan om te versprei en het ook die potensiaal om uit te brui onder veranderende klimaat
scenario's. Die tweede deel van die studie wys dat versprei langs die Sabie-Sandopvanggebied
hoofsaaklik rivier-gedrewe is en dat die Sand sytak die inval bron is. Omdat
die Sand sytak buite die Kruger Nasionale Park ontstaan, en slegs 'n klein gedeelte onder park
bestuur is, is die implikasies vir verspreiding belangrik. / Financial support from the DST-NRF Centre of Excellence for Invasion
Biology and the Working for Water (WfW) Programme through their collaborative project on
“Research for Integrated Management of Invasive Alien Species” and Stellenbosch
University’s Subcommittee B Young Researcher's Fund
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/20378 |
| Date | 03 1900 |
| Creators | Vardien, Waafeka |
| Contributors | Le Roux, Johannes J., Richardson, David M., Foxcroft, Llewellyn C., Wilson, John R., Stellenbosch University. Faculty of Science. Dept. of Botany and Zoology. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | xii, 85 p. : ill., maps |
| Rights | Stellenbosch University |
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