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Masters Degrees (Plant Pathology)

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Browsing Masters Degrees (Plant Pathology) by Author "Burgdorf, Richard."

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    Investigating the utilization of indigenous forestry as a pathway for commercial forestry, community upliftment and land restoration.
    (2024) Mathenjwa, Kuhlekonke Khulani.; Mbili, Nokwazi Carol.; Burgdorf, Richard.; Laing, Mark Delmege.; Sardeshpande, Mallika.
    Forests play a vital role in sustaining ecological balance and providing essential resources for human well-being. In South Africa, forestry has predominantly relied on non-indigenous tree species, leading to limited natural forests and an increasing dependence on commercial forest plantations. These plantations are mainly made up of commercial exotic monocultures constituting pine, wattle, and eucalyptus species. Some of these exotic species tend to colonize the natural environments of local indigenous species and grasslands where they ultimately alter the soil and water conditions to outcompete local species. In addition, due to their greater growth forms than indigenous tree species, they alter the structure of natural vegetation which negatively impacts nutrient cycles and water availability. As a result, the need to explore alternative approaches in forestry that prioritize indigenous tree species has become evident. While indigenous commercial forestry is practiced globally, South Africa has untapped potential due to the limited number of indigenous tree plantations in the country. To explore the use of indigenous trees, the main aim of the project was to investigate the use of indigenous trees for commercial forestry, community development, as well as land restoration by assessing and evaluating the growth and survival of indigenous species through the application of propagation methods and the incorporation of plant growth-promoting fungus Trichoderma asperellum (Eco-T). This was followed by assessing ecological benefits of indigenous trees such as biodiversity conservation, soil nutrient analysis, and evaluating cost-effective methods and market potential for indigenous tree propagation, as well as the recovery of trees in anthropogenic soils. This aim was firstly achieved by assessing the feasibility and potential of indigenous forestry in South Africa through a literature search and then further reported on indigenous tree species' importance and utilization along with their associated resources. Subsequently, this research investigated the utilization of indigenous tree species in South Africa, particularly within three peri-urban communities of the eThekwini municipality, KwaZulu-Natal. The first phase of sampling followed snowballing sampling strategy through assistance from local authorities (N=29), and a questionnaire was administered at one of the focus group discussions (N=10). The second phase of sampling used purposive sampling strategy to identify interviewees (N=10). Ethnobotanical data was collected and a total of 21 indigenous tree species were identified and reported across the three communities, emphasizing the utilization patterns and preferences of local species. Amongst the reported species, 12 species were utilized in either all three or two communities. Across all three sites, four indigenous tree species emerged as the most commonly utilized species, notably, Sclerocarya birrea, Prunas africana, Trichilia emetica and Ficus sur, accounting for 90% of participants (n=20). Fruits and medicinal products derived from bark and leaves were the most commonly utilized resource products from indigenous trees, constituting 60% of overall usage by participants. These findings highlighted that indigenous tree species with multiple uses were commonly utilized more than those species with one use, which elucidates the commercial value and economic potential of those. Treepreneurs emerged as pivotal components in this study that showcased profound knowledge and commitment to indigenous tree propagation and cultivation, expressing a clear preference for indigenous species over alien invasive plants. Hence, understanding the perspectives and needs of the local community is essential for the successful implementation of indigenous commercial forestry. The growth of indigenous tree species under field and greenhouse conditions was assessed. A total of five indigenous tree species namely Trichilia emetica, Harpephyllum caffrum, Sclerocarya birrea, Ficus sur and Canthium inerme were selected for this study based on the preliminary findings of the ethnobotanical survey. Tree seedling growth and survival were the important parameters evaluated in this study to investigate the impact of Trichoderma asperellum (Eco-T) on the growth of indigenous tree species. Noteworthy results obtained from the field growth establishment trial include the highest survival rate H. caffrum and the fastest growth in F. sur, accounting for 100% and 33.13 cm, respectively. However, the application of Trichoderma treatment did not have any significant impact on the growth and survival of the indigenous tree species. These findings lay a great foundation for the cultivation, survival, and growth of indigenous tree species under field conditions. Greenhouse cultivation of indigenous tree species was conducted using anthropogenic soils from degraded lands. Here, the growth forms of indigenous tree species compared to the exotic species Eucalyptus grandis were investigated. The application of Eco-T as a treatment was also examined on the survival and growth of the seedlings. Indigenous tree seedlings exhibited a high survival percentage except for S. birrea in both Eco-T treated and untreated samples, accounting for 67 and 92%, respectively. Notably, the overall highest change in growth of height was observed in seedlings of F. sur with 48.8 cm but not as high as that of the control sample accounting for 106.16 cm. However, the treatment did not have any significant impact on the growth and survival of indigenous tree species. These results highlight the potential expressed by indigenous tree species especially F. sur under field and greenhouse conditions, in forestry and land restoration. They further emphasize the need for the development of specific indigenous tree species of commercial and ecological value. Furthermore, this study investigated the effect of different rooting hormones in the growth of different indigenous tree species from stem cuttings and then assessed the feasibility of propagating indigenous tree species using cuttings. In this study, four treatments namely Seradix, Dip n Grow, Eco-T and control were tested on three cutting types of the five indigenous tree species. All treatments showed no significant impact on the survival and growth of the species. At the end of the growing period, only one out of five species had survived, sprouted and rooted, accounting for 16% of F. sur. High mortality was observed at the end of the growing period (12 weeks) and can be accounted by various factors such as oversaturation on growing medium, temperature, and moisture. The findings revealed to yield great propagation success, compatibility of rooting hormones, type of species and cutting type must be taken into consideration. The findings further reveal the slight feasibility of propagating indigenous tree species from stem cutting, but also express great potential for F. sur. Hence, more research and development are needed to explore the potential of F. sur as well as other important indigenous tree species that can add value in forestry and be utilized for commercial purposes. Lastly, this study could provide valuable information for forestry managers, researchers, and policy makers to support the conservation and sustainable management of indigenous tree species. Overall, it can serve as a blueprint for similar initiatives and can be applied in various contexts advocating for a more inclusive, ecologically sound, and sustainable approach in the forestry sector.