Thesis (Ph.D.)--University of Wollongong, 2007. / Typescript. Includes bibliographical references: leaf 133-154.

Thesis (Ph.D.)--University of Washington, 1994. / Vita. Includes bibliographical references.

Thesis (Ph.D.)--University of Wyoming, 2009. / Title from PDF title page (viewed on Apr. 15, 2010). Includes bibliographical references.

Thesis (M.S.)--Oregon State University, 2004. / Printout. Includes bibliographical references (leaves 84-90). Also available via the World Wide Web.

Thesis (MScConEcol)--University of Stellenbosch, 2008. / Bibliography. Also available via the Internet.

Thesis (M.Sc.)--Memorial University of Newfoundland, 2002. / Bibliography: leaves 144-155.

Alien invasive species pose a great threat to ecosystems and human communities (Richardson & van Wilgen 2004; Hobbs & Humphries 1995). On private lands, there is a need to find institutional, administrative and scientific responses to the alien plant problem that operate beyond the scale imposed by property boundaries (Slocombe 1998; Grumbine 1994). One such response is the development and support of institutions, such as the St Francis Conservancy, that foster cross-boundary management of landscapes (Hurley et al. 2002). This study seeks to promote collective decision-making and collaborative management by private landowners through the development of a resource allocation system for the control of alien invasive plants on the St Francis Conservancy. The conservancy is located in the south-eastern lowlands of the Cape Floristic Region, between the villages of Cape St Francis and Oyster Bay, and is comprised of the properties of multiple landowners. Mutliple Criteria Decision Analysis (MCDA) and Geographical Information Systems (GIS) techniques were integrated to provide a spatially explicit resource allocation system that considered environmental, social and economic concerns. The MCDA technique selected for use was the Analytical Hierarchy Process (AHP). This technique has a record of providing robust, defensible decisions and enabled the resource allocation decision-problem to be decomposed into a hierarchy of objectives, criteria and indicators. Stakeholders participated in the development of the resource allocation system, especially through providing input into the determination of the relative importance of criteria and indicators through the assignment of weights. Various weighting scenarios were presented and these were interpreted into an ii implementation plan. The costs and effort required to clear alien plants were estimated, and obstacles facing the implementation of the plan were identified.

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, in partial fulfilment of the requirements of the degree of Master of Science, Johannesburg, 2018 / Grevillea robusta is classified as a Category 3 invader by the National Environmental Management: Biodiversity Act (NEMBA) in South Africa. The species has recently been observed invading riparian areas from old cultivated trees in Limpopo, Mpumalanga and Gauteng provinces. Since the early 1980’s Grevillea robusta A.Cunn populations have increased from 15 observations in 1980─1985 to 39 in 1996─2000 and 47 between 2016 and 2017 in South Africa. The species is currently distributed in a total of 188 localities in 7 South African provinces. The aim of this study was to assess the invasiveness of G. robusta in South Africa and determine its appropriate Category status by assessing its invasive capacity by conducting a population census and assessing its transformative capacity at Moederlief farm, South Africa. Grevillea robusta is widespread in South Africa, however, there are no recorded observations in the Free State and Northern Cape provinces. The results from iSpot, CLIMEX, Southern African Plant Invaders Atlas (SAPIA) and field observations in figures 13, 14, 15 and 16 shows 52 observations in Limpopo and 37 between KwaZulu-Natal and Mpumalanga provinces. A climatic match index by CLIMEX was employed, and results indicate that G. robusta has the potential to grow well in Limpopo, Mpumalanga and Gauteng provinces and along the coastal regions. Furthermore, healthy populations of G. robusta were observed at Moederlief farm, where the biggest recorded tree in the field was estimated to be 45 to 52 years old. Grevillea robusta produces viable seed which may be dispersed 364 m away from parent trees. Looking at the population structure, age of reproduction, seed viability and ease of dispersal, the populations of G. robusta at Moederlief farm will continue to grow and invade even in other areas that are yet to be considered risk areas. Grevillea robusta is an invader that needs further evaluation of all the localities in South Africa. The species should be placed in Category 1b of invasive species and immediate control is required in all riparian zones. / XL2019

MSc., Faculty of Science, University of the Witwatersrand, 2011 / This research investigated the susceptibility of South African indigenous aquatic plants to competition from invasive species, using the competitive interactions of two sets of aquatic plants as a potential indicator. These interactions were studied in two separate experiments: the submersed weeds, Hydrilla verticillata (L.F.) Royle (Hydrocharitaceae) and an indigenous species, Lagarosiphon major (Ridley) Moss (Hydrocharitaceae) and; the floating weeds, Azolla filiculoides Lamarck (Azollaceae) and the indigenous Spirodela polyrhiza (L.) Schleid (Lemnaceae). Plants were grown under differing nutrient levels, and in an addition series of eight different densities, using the reciprocal yield model to estimate competitive ability. The invasive Hydrilla outcompeted Lagarosiphon in terms of mean length, dry mass, and survival. Major algal infestation in the high nutrient level of the Hydrilla/Lagarosiphon experiment altered light and nutrient conditions, which may have played a significant role in the lack of establishment of Lagarosiphon and the poor growth performance of Hydrilla. The invasive Azolla and indigenous Spirodela both performed well in terms of plant mass and increase in number. While Azolla was affected by intraspecific competition, it showed a steady increase in growth and multiplication with an increase in nutrients. The individual mass of Spirodela plants was highest in the low nutrient level, and multiplication rates were greatest in the high nutrient level. Results indicate that the susceptibility of indigenous plants may be increased in highnutrient systems, and that a continuous monitoring programme of aquatic alien species is vital in protecting our indigenous plants from extinction. This research recommends that the method of investigating competitive interactions between alien and indigenous plants be repeated with a variety of aquatic plants, as a means of anticipating susceptibility to invasions.

Title from title page of PDF (University of Missouri--St. Louis, viewed March 10, 2010). Includes bibliographical references (p. 26-31).