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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Understanding the present and historic forest resource use of the Ntabamhlope indigenous state forest by rural communities.

Mthimkhulu, Oscar. January 2009 (has links)
Ntabamhlophe indigenous state forest is the focus study area. It is one of the forests that are found along the Drakensberg mountain range in KwaZulu- Natal province in South Africa. It is a proclaimed forest of approximately 50ha in extent. The Ntabamhlophe indigenous state forest was formerly called Monk’s Cowl State Forest, (Monk’s Cowl State Forest - iNtabamhlophe) situated in central uKhahlamba Drakensberg Park World Heritage Site, KwaZulu-Natal, South Africa. This forest is located on communal land. In many parts of the world, indigenous forests face growing threats and pressures. Internationally this has resulted in approximately 9.4 million hectares being lost by 1990. Indigenous forests play an important role in ecosystem processes. They are associated with a range of products and processes that support the livelihood of millions of people around the world. Forests cover more than 3 000 km2 or 0.1% of the land surface of South Africa. Furthermore, due to the lack of appropriate management programmes, South Africa has contributed its share to indigenous forest loss. Approximately 76% (3240ha) of the Drakensberg Montane forest is formally protected South Africa’s geographical positioning is such that it has historically had a smaller extent of forests. The future of South Africa’s remaining indigenous forests depends partly on the values ascribed to them by local communities. The study objectives were, (i) to understand the values and perceptions of the community towards the existence and future management of the Ntabamhlophe indigenous state forest, and (ii) to determine the different types of forest products and resources used by the community and their values to the users (cultural, spiritual or economic values). To understand Ntabamhlophe community’s indigenous forest resource use, values and perceptions, a qualitative survey method was used. This was conducted by using focus group techniques. The use of focus groups provided an insight into qualitative data. The technique combined both wise counsel and focus group workshops. The use of this technique aimed at drawing upon respondents’ attitudes, feelings, beliefs, experiences and reactions. The questionnaire design was based on the structures of other studies, on user attitudes and values relating to forest resources. The study revealed that the community ascribes high values to the indigenous forest, however they do not have a proper forest management system in place. The following were regarded as the major threats facing Ntabamhlophe forest resources: crime, uncontrolled and excessive burning, uncontrolled harvesting of indigenous medicinal plant and fuelwood, deforestation (clearing forests for plantations, e.g. vegetable crops and Cannabis sativa). Illegal hunting, soil erosion, and inappropriate forest management systems (nonexistence) were all considered by community representatives as serious threats to the survival of this indigenous forest. The findings also revealed that there is a lack of capacity and skills, appropriate stakeholder representation and coherent community leadership to pursue Ntabamhlophe Mountain and forest conservation initiatives. Given the circumstances, there is an apparent lack of confidence on the part of the community to confirm their natural resource conservation priorities. The community representatives recommended that the current uncontrolled activities be prohibited. They also had a strong belief that the forest should be protected through a cooperative management system involving Ezemvelo KZN Wildlife, the Traditional Authority, the Department of Water Affairs and Forestry and Imbabazane Local Municipality. The focus group indicated that they had a very high future benefit expectation of activities such as education, water, cultural, biodiversity, spiritual upliftment, tourism, craft and free access (Table 6). They also indicated that gathering medicinal plants and fuelwood was very common. Educational benefit was regarded as the most important of all, followed by tourism and biodiversity conservation. / Thesis (M.Env.Dev.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.
2

Above-ground allometry, biomass and nutrient content of acacia mearnsii across four ages and three sites in the Kwazulu-Natal Midlands.

Dovey, Steven B. January 2005 (has links)
Acacia mearnsii (black wattle) is one of the few tree crops of which both timber and bark are utilised, with branches sometimes being collected for fuel wood. There is a great potential for nutrient loss from plantations with intense harvesting practices. Allometric relationships were developed to estimate above-ground biomass across four ages and three site qualities of A. meamsii stands. The three sites were based on high, medium and low site quality classes of productivity. Differences in biomass and the distribution of biomass between the stem, bark, live branches, dead branches and foliage components are described in relation to site and age. Relationships between biomass and light interception and plant area index are investigated and show some merit. Nutrient concentrations were used with the above-ground biomass data to estimate quantities of nutrients held in the various biomass components in each of the stands. Nutrient distributions in the above-ground biomass (AGB) were examined and compared to other studies. Foliar phosphorus (P) and potassium (K) concentrations were shown to be sub optimal, agreeing with results and recommendations of South African fertilisation stupies. Some concentration differences were observed between site and age classes for certain nutrients, although these differences may have been due to seasonal effects. Biomass and nutrient quantities were adjusted to yield a wood production of 100 t ha01 and compared with adjusted calculations for similar studies on other plantation crops. Total nutrients contained in the AGB of the adjusted calculations were 540.8 kg ha01 nitrogen (N), 20.4 kg ha-I P, 200.6 kg ha01 K, 241 kg ha-I calcium (Ca), 55.7 kg ha-I magnesium (Mg), with a half to two thirds of the nutrients held in the stem and bark alone. Nutrients losses vary with harvesting intensity as bark and branches may be harvested with the stem wood. Levels of nutrient removal with harvesting intensity are discussed with reference to estimated losses and gains from natural processes and management practices. An incomplete nutrient budget calculation indicated that P, K, Ca and Mg might potentially be removed in quantities greater than replaced by natural processes under stem and bark harvesting. The budget calculations lack processes such as leaching and N-fixation. It is highly probable that these processes, once quantified, may yield more negative budget results, especially for the base cations K, Ca and Mg. / Thesis (M.Sc.)-University of KwaZulu- Natal, Durban, 2005.
3

Conservation, forest resources and sustainable rural livelihoods : a case study of Saint Bernard Community, KwaZulu-Natal.

Buthelezi, Dumisani Lucas. January 2007 (has links)
There is a growing body of literature that outlines a contemporary view of the role of forests and forestry in rural development. The most common argument highlighted by the contemporary literature indicates that forests provide a wide variety of important products, both for subsistence purposes and as sources of income. This study is based on the premise that an understanding of the issues that relate to access and utilization of forest resources and their management cannot be neglected in the field of rural development, more especially in the African context wherein much of the population is still defined as rural dwellers. Furthermore, given the paradigm shifts that have been witnessed in both the approaches to rural development and natural resource management over the years, it is necessary to examine how forestry has responded to new demands, particularly in relation to its contribution to rural livelihoods. This study intended to examine the conservation and management of forest resources and their impact on sustaining rural livelihoods by using the case study of the Saint Bernard community in the Nhlazuka village in Richmond, KwaZulu-Natal province. In Saint Bernard, a communal system of managing community resources such as trees and forests forms an integral part of decision-making. The study looked at the management of both the natural and plantation forests and their impact on the livelihoods of rural communities, especially in communally owned areas. Given the nature of this study, both qualitative and quantitative methods of social science research were employed to generate data relating to the research objectives and questions. Qualitative participatory techniques used include the ranking exercise, mental mapping and venn diagram. Quantitative data was mainly obtained through a questionnaire survey. The primary data was supplemented with the secondary data relating to the focus of this study. / Thesis (M.A.)-University of KwaZulu-Natal, 2007.
4

Biodiversity criteria and indicators for the sustainable management of industrial plantations.

Linnett, Elizabeth. January 1999 (has links)
Abstract not available. / Thesis (M.Env.Dev.)-University of Natal, Pietermaritzburg, 1999.
5

The challenges of forest policy implementation on small-scale commercial timber growers : a case study of Forestry South Africa in the Midlands region, KwaZulu-Natal.

Ndlela, Nkosinathi Erick. January 2004 (has links)
Timber forms an essential element of people lives especially those residing in rural areas. Most wood is used for fuel, building purpose; industrial uses include construction; mine props and paper products. Through commercialisation timber is sold and exported to different countries out of South Africa for great returns. Most of commercial plantations are located primarily in the Northeast and in KwaZulu-Natal; most timber plantations produce pine and eucalyptus trees. This case study examines the challenges of forest policy implementation on small-scale timber growers. The study was based on smallscale commercial timber grower committees and chairpersons of the mentioned committees. The study was carried out in mid September and October 2004. A quantity survey through face-to-face interviews of chairpersons of small growers committees was undertaken. Also a focus group interviews of committee members was carried out. The result showed that chairpersons and committee members do not know the Forest Act NO.84 of 1998. The forest policy implementation poses great challenges for small growers as there is a lack of information between government and growers in the respective area of operation about forestry and how it should be sustained. / Thesis (M.Soc.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2004.
6

Land cover classification in a heterogeneous environment : testing the perfomance of multispectral remote sensing data and the random forest ensemble algorithm.

Ndyamboti, Kuhle Siseko. 06 June 2014 (has links)
Land use/land cover (LULC) information is essential for a plethora of applications including environmental monitoring and natural resource management. Traditionally, field surveying techniques were the sole source of acquiring such information; however, these methods are labour intensive, costly and time consuming. With the advent of remote sensing, LULC information can be acquired in an economical, less tedious and non-time consuming manner at shorter temporal cycles and over larger areas. The aim of this study was to assess the utility of multispectral remote sensing data and the Random Forest (RF) algorithm to improve accuracy of LULC maps in heterogeneous ecosystems. The first part of this study used moderate resolution SPOT-5 data to compare the performance of the RF algorithm to that of the commonly used Maximum Likelihood (ML) classifier. Results indicated that RF performed significantly better than ML (66.1%) and yielded an overall accuracy of 80.2%. Moreover, RF variable importance measures were able to provide an insight on the bands that played a pivotal role in the classification process. Due to the fact that moderate resolution satellite data was used, both classifiers seemed to experience some difficulties in discriminating amongst classes that exhibited similar spectral responses such as Eucalyptus grandis and Pinus tree plantations, young sugarcane and mature sugarcane, as well as river and ocean water. In that regard, the next section attempted to address this shortfall. The second part of the study used high resolution multispectral data acquired from the WorldView-2 sensor to discriminate amongst six spectrally similar LULC classes using the advanced RF algorithm. Results suggested that the use of WorldView-2 data together with the RF ensemble algorithm is a robust and accurate method for separating classes exhibiting similar spectral responses. The classification process yielded an overall accuracy of 91.23% and also provided valuable insight into WorldView-2 bands that were most suitable for discriminating the LULC categories. Overall, the study concluded that: (i) multispectral remote sensing data is an effective tool for obtaining accurate and timely LULC information, (ii) moderate resolution multispectral data can be used to map broad LULC categories whereas high resolution multispectral data can be used to separate LULC at finer levels of detail, (iii) RF is a robust and effective tool for producing LULC maps that are less prone to error. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2013.
7

An assessment of canopy and litter interception in commercial and indigenous forests in the KwaZulu-Natal Midlands, South Africa.

Bulcock, Hartley Hugh. January 2011 (has links)
Understanding of the hydrological cycle and processes such as interception span as far back as the times of the Renaissance, when Leonardo da Vinci (1452-1519) first described it. However, there remains a gap in the knowledge of both canopy and litter interception in South African forest hydrology. Interception is typically considered to constitute only a small portion of total evaporation and in some models is disregarded or merely lumped with total evaporation, and not considered as a separate process. Interception is a threshold process, as a certain amount of water is required before successive processes such as infiltration and runoff can take place. Therefore an error introduced in modelling interception, especially disregarding it, will automatically introduce errors in the calibration of subsequent models/processes. In this study, field experiments to assess these two poorly understood hydrological processes, viz. canopy and litter interception were established for the three main commercial forestry genera in South Africa, namely, Pinus, Acacia and Eucalyptus as well as an indigenous Podocarpus henkelii stand, thus, accounting for interception of “broad leaf”, “compound leaf” and “needle leaf” trees in order to provide further insight into these processes. The study took place at two locations in the KwaZulu-Natal Midlands over a period of three years. The first site is the Two Streams catchment, located in the Seven Oaks area, about 70km north-east of Pietermaritzburg where the study on the commercial plantation species took place. The second site was the Podocarpus henkelii stand in Karkloof near Howick, 40km north of Pietermaritzburg. From the field data collected (cf. Chapter 2) it was observed that canopy storage capacity, an important parameter governing interception, was not constant and changed with rainfall intensity, with lower intensity events resulting in a higher storage capacity. Building on these findings, a physically based canopy interception model that is based on the well known Gash model was developed, and is referred to herein as the “variable storage Gash model”. While canopy interception is dependent on many factors including the storage capacity, potential evaporation, rainfall intensity and rainfall duration, the litter interception is largely dependent on the storage capacity due to the evaporative drivers under the canopy such as radiation, temperature and wind speed being moderated by the above canopy. From these finding, a litter interception model based on idealised drying curves from litter samples collected at the study sites was also developed (cf. Chapter 3). From the field data, it was found that the canopy interception for Eucalyptus grandis, Acacia mearnsii and Pinus patula was 14.9, 27.7 and 21.4% of mean annual precipitation (MAP) respectively. The simulated canopy interception using the “variable storage Gash model” was 16.9%, 26.6% and 23.3% for E. grandis, A. mearnsii and P. patula respectively. The litter interception measured for E. grandis, A. mearnsii and P. patula was found to be 8.5, 6.6 and 12.1% of MAP respectively, while the simulated litter interception using the idealised drying curve model corresponded well with the measured results and were 10.1%, 5.4% and 13.4% for E. grandis, A. mearnsii and P. patula respectively. The idealised drying curve model is site and species specific and is therefore not transferable to other locations. Conversely, the “variable storage Gash model” is transferable as it is not site and species specific, and relies on readily measureable and available information. Building on field studies, this was then used to simulate the canopy interception for Eucalyptus, Acacia mearnsii and Pinus in South Africa (including Lesotho and Swaziland) for all quinary catchments in which commercial forestry could be grown, i.e. a mean annual precipitation of greater than 600 mm.year-1 (cf. Chapter 4). It was found that, depending on the location and genus, canopy interception loss can be as high as 100 to 300 mm per year or approximately 10% to 40% of MAP. This relates to a mean interception loss of between 1.0 and 3.0 mm per rainday, highlighting the spatial variability of canopy interception. To further investigate the spatial variability of canopy interception, at various spatial scales, remote sensing technology was applied to estimate leaf area index (LAI) for use in modelling/estimating canopy storage capacity and canopy interception (cf. Chapter 6). The NDVI, SAVI and Vogelmann 1 vegetation indices were used in the estimation of the LAI. It was found the Vogelmann 1 index produced the best results. As models to estimate canopy interception typically require LAI and storage capacity, it was calculated that the ability to estimate these parameters over large areas is valuable for water resources managers and planners. An often neglected consideration of canopy and litter interception is its role in determining the water use efficiency (WUE) of a forest stand (cf. Chapter 5). This component of the study was undertaken in an indigenous Podocarpus henkelii stand as well as a commercial Pinus patula stand in Karkloof in the KwaZulu-Natal Midlands. The sap flow (transpiration) was measured in both the P. henkelii and P. patula stands using the using the Heat Pulse Velocity (HPV) technique in order to determine the productive green water use. The canopy and litter interception was measured in the P. henkelii site, but was modelled in the P. patula site using the “variable storage Gash” and idealised drying curve models, in order to estimate the non-productive green water use. It was found that the canopy and litter interception for P. henkelii was 29.8% and 6.2% respectively, while the modelled canopy and litter interception for P. patula was 22.1% and 10.7% respectively. If only the productive green water use (transpiration) is considered, then the water use efficiency of P. henkelii and P. patula was found to be 7.14 g.mm-1 and 25.21 g.mm-1 respectively. However, from a water management perspective it is important to consider the total green water use efficiency (transpiration + interception), which reveals a significantly lower water use efficiency of 3.8 g.mm-1 and 18.8 g.mm-1 for P. henkelii and P. patula respectively. To extend the study to a globally relavent issue, the possible impact of climate change on canopy interception was investigated, as forests growth is critically linked to climate (cf. Chapter 7). To achieve this, the CABALA model was used to model LAI and transpiration of Eucalyptus grandis and Pinus patula under 9 different climate change scenarios, including changes in temperature, rainfall and atmospheric CO2. The simulated LAI values from the CABALA model for all 9 climate scenarios were then used to simulate canopy interception using the “variable storage Gash model”. Results show that LAI may increase by as much as 24% and transpiration may decrease by as much as 13%, depending on the scenario, location and tree species. However, it was found that canopy interception does not change greatly, leading to the conclusion that under climate change conditions, canopy interception may not become a more dominant component of the hydrological cycle than it currently is as the changes under climate change are likely to be less than the natural variability from year to year. However, canopy interception remains an important consideration for water resources management and planning both currently and in the future. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.
8

Remote sensing of forest health : the detection and mapping of Thaumastocoris peregrinus damage in plantation forests.

Oumar, Zakariyyaa. January 2012 (has links)
Thaumastocoris peregrinus (T. peregrinus) is a sap-sucking insect that feeds on Eucalyptus leaves. It poses a major threat to the forest sector by reducing the photosynthetic ability of the tree, resulting in stunted growth and even death of severely infested trees. The foliage of the tree infested with T. peregrinus turns into a deep red-brown colour starting at the northern side of the canopy but progressively spreads to the entire canopy. The monitoring of T. peregrinus and the effect it has on plantation health is essential to ensure productivity and future sustainability of forest yields. Insitu hyperspectral remote sensing combined with greater availability and lower cost of new generation multispectral satellite data, provides opportunities to detect and map T. peregrinus damage in plantation forests. This research advocates the development of remote sensing techniques to accurately detect and map T. peregrinus damage, an assessment that is critically needed to monitor plantation health in South Africa. The study first provides an overview of how improvements in multispectral and hyperspectral technology can be used to detect and map T. peregrinus damage, based on the previous work done on the remote sensing of forest pests. Secondly, the utility of field hyperspectral remote sensing in predicting T. peregrinus damage was tested. High resolution field spectral data that was resampled to the Hyperion sensor successfully predicted T. peregrinus damage with high accuracies using narrowband normalized indices and vegetation indices. Field spectroscopy was further tested in predicting water stress induced by T. peregrinus infestation, in order to identify early physiological stages of damage. A neural network algorithm successfully predicted plant water content and equivalent water thickness in T. peregrinus infested plantations. The result is promising for forest health monitoring programmes in detecting previsual physiological stages of damage. The analysis was then upscaled from field hyperspectral sensing to spaceborne sensing using the new generation WorldView-2 multispectral sensor, which contains key vegetation wavelengths. Partial least squares regression models were developed from the WorldView-2 bands and indices and significant predictors were identified by variable importance scores. The red edge and near-infrared bands of the WorldView-2 sensor, together with pigment specific indices predicted and mapped T. peregrinus damage with high accuracies. The study further combined environmental variables and vegetation indices calculated from the WorldView-2 imagery to improve the prediction and mapping of T. peregrinus damage using a multiple stepwise regression approach. The regression model selected the near infrared band 8 of the WorldView-2 sensor and the temperature dataset to predict and map T. peregrinus damage with high accuracies on an independent test dataset. This research contributes to the field of knowledge by developing innovative remote sensing techniques that can accurately detect and map T. peregrinus damage using the new generation WorldView-2 sensor. The result is significant for forest health monitoring and highlights the importance of improved sensors which contain key vegetation wavelengths for plantation health assessments. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.
9

Comparative evaluation of Celtis africana in Lesotho with that in KwaZulu-Natal, South Africa.

Ts'ehlana, Moses Ts'eliso. January 2005 (has links)
Research was conducted in three study sites in Lesotho, and the fourth, which was used on comparative basis, was in KwaZulu-Natal, South Africa. The study was suitable for Lesotho as it is a small country with very limited natural resources. Lesotho's weak economy, exacerbated by the increasing population, needs concerted efforts to redress its socio-economic problems. This study is one of such efforts to explore the potentials of the indigenous forests with the aim of addressing wood demands. Celtis africana is one of the species with a proven record in Lesotho to have been a well adapted, resourceful timber tree in the past. Over-exploitation has degenerated it to its brink of extinction. It is against this background that this research was conducted with the aim of restoring Celtis africana to its original status in Lesotho. The results revealed that due to climatic conditions, seeds from Kwazulu-Natal are heavier than those from localities in Lesotho. However, wood densities from study sites in Lesotho are higher than those of KwaZulu-Natal. Pre-treatment method of manual scarification showed the best outcomes in terms of germination percent and vigour while the control was the last. The diverse nature of Celtis africana allows it to survive and prosper in a wide and varying range of habitats. Its pliable and adaptive characters are manifested by its ability to adapt in novel environments. Under ideal warm and moist conditions Celtis africana keeps its foliage all the year round, but in dry or abnormally cold years it becomes a deciduous tree. Though it is distributed in a variety of habitats, Celtis africana prefers moist habitats. It also demonstrates greater "affinities" for the carbonates in the soils, in particular, calcium carbonate (CaC03) and dolomite (CaMgC03). More research and determined reforestation programmes are required in order to improve the status of Celtis africana in Lesotho. Its natural existence in Lesotho can curtail expense of provenance identification. Both extension strategies and silvicultural operations, which can assist in tree improvement, should be adopted. Social benefits which, are rendered by Celtis africana in South Africa, can be emulated and adopted in Lesotho. Other than being an admired and valuable recreational tree (planted in parks and in the homesteads), it is a protected tree in South Africa. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

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