• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 21
  • 4
  • 4
  • 1
  • Tagged with
  • 48
  • 20
  • 19
  • 16
  • 14
  • 10
  • 9
  • 8
  • 8
  • 8
  • 8
  • 7
  • 6
  • 6
  • 6
  • 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.
31

Rangeland management practices among emerging livestock farmers in Gauteng province, South Africa

Letsoalo, Ngoako Lucas 01 1900 (has links)
In South Africa, communal and/or emerging farmers’ rangeland condition and grazing capacities deteriorate, because grazing capacity is usually over-estimated due to lack of knowledge on veld and livestock production system by the farmers. Woody plants has encroached in the arid and semi-arid savannas and grasslands biomes many parts of world, including in southern Africa. This causes challenges to farm owners due to its negative effects on the herbaceous plant material, which offers a substantial part of forage for livestock production. Although the consequences of deteriorating rangeland condition on livestock production is understood, there is limited research on the impact of land ownership on rangeland condition. Furthermore, knowledge on how farmers manages their livestock and rangelands. The objectives were to document the knowledge of emerging livestock farmers on livestock-rangeland management practices, and to determine the effects of land ownership and practices on rangeland condition. Firstly, we hypothesize that, emerging livestock farmers unknowingly manages livestock in isolation from their rangelands, and secondly, rangeland in private owned lands are relatively in good conditions compared to communal and leased lands. Fifty (50) emerging livestock farmers (i.e. ruminants) in different vegetation types and district municipalities of the Gauteng province were selected using a snowball procedure. To investigate the knowledge of emerging farmers on livestock - rangeland management practices, the farmers were asked questions about their 1) demographic information, 2) livestock management practices and 3) rangeland management practices. To test the differences in farmers’ demographic profiles, Chi-square statistics was employed. To determine the effects of land ownership on rangeland condition of the selected farms, rangeland condition among three land ownership types was compared using ANOVA, and the relations between veld condition score (%) and herbaceous biomass production (kg DM/ha) was tested using Pearson’s correlation analysis The results revealed that, the emerging livestock farmer are dominated by males (68 %) compared to female (32%). Majority (66%) of the farmers are old aged (> 50 years) compared to middle aged (30% (31 – 50 years)) and young (< 30 years) farmers (4%). Farmers who did not receive any agricultural training were higher (74%) than farmers who had prior training (26%). Sixty-three percent of the farmers had knowledge and understanding of breeding and calving seasons of their livestock, with only 27% having no knowledge and understanding of breeding and calving seasons of their animals. Eighty-three percent of the farmers keep mixed livestock (cattle, sheep and goats) species and 17% only keep cattle. The mean cattle herd sizes were significantly lower 8.2 ± 7.16 compared to goats and sheep (15.5 ±11.2). Feed shortage was the major constrain to livestock production (46%) compared to diseases (26%), marketing (14%), stock theft (8%) and other (6%) constrains. Sixty-three percent of the farmers had knowledge and understanding of breeding and calving seasons of their livestock, with only 27% having no knowledge and understanding. Eighty-three percent of the farmers keep mixed livestock (cattle, sheep and goats) species and 17% only keep cattle. All of the farmers indicated that they did not conduct rangeland condition assessment (mainly due to lack of knowledge). All farmers did not have fodder conservation plan for their farms and highlighted that during dry season, forage is scarce for their animals. Majority (58%) of the farmers relay on government-drought relief programme compared to those who were supplementing (20%), selling their animals (14%) and those with no drought coping strategy (8%). v Vegetation was assessed using nearest plant technique. In total, 28 grass species were identified during field survey, of which n=23, n=4 and n=2 were perennials, annuals and short-lived perennial, respectively. The most commonly observed and very palatable grass species, Digitaria eriantha had the highest frequency on private lands (n=92 and the lowest on communal lands (n=51). There were no significance difference in grass species richness and basal cover among land ownership types (P > 0.05). There were significant differences in veld condition score, large stock units, grazing capacity and herbaceous biomass production among land ownership types (P < 0.05). Private lands had a significantly higher veld condition score (69.63%) than leased (56.07%) and communal lands (52.55%). The herbaceous biomass production was positively correlated to the veld condition score (r = 0.159; P<0.005). The outcomes of this study show that emerging livestock farmers in Gauteng province have little understanding of rangeland-livestock management practices. The current results further indicated that poor grazing practices such as overgrazing might be common on leased and communal lands due to farmers’ lack of knowledge on rangeland management practices. This may lead to rangeland degradation thus negatively affecting livestock production and the livelihood of farmers who rely on farming as a source of income. / Agriculture, Animal Health and Human Ecology / M. Sc. (Agriculture)
32

Assessment of veld utilisation practices and veld condition in the Little Karoo

Cupido, Clement F. 03 1900 (has links)
Thesis (MScConsEcol (Conservation Ecology and Entomology))--University of Stellenbosch, 2005. / The veld condition in the Little Karoo is in various states of degradation and grazing by domestic livestock is considered as the major anthropogenic force that changed the landscape. This region with its extremely rich plant species diversity and endemics, has supported small livestock for at least 2 000 years, and since colonization (250 years ago) been intensively used for the production of a variety of livestock. Ostrich production developed as the major source of income for this region. The first part of this study investigates the current veld management practices employed by livestock farmers in the Little Karoo region. Recommended veld management practices considered in this study are grazing rotation, moderate stocking rate control, moderate veld utilisation, separation of ecotopes, veld rehabilitation, controlling declared weeds and alien vegetation and regular assessment of veld condition. One hundred randomly selected farmers were personally interviewed by means of a structured questionnaire. Questions were grouped into the following categories: (a) demography of farmers, (b) ostrich farming, (c) perceptions and knowledge of farmers on farming practices, (d) grazing rotation, (e) stocking rate, (f) veld utilisation and veld assessment, (g) separation of ecotopes, (h) veld rehabilitation, (i) control of alien vegetation and (j) farmers’ knowledge on legislation. This was used to obtain information on the Little Karoo farming community, sizes of farms and camps, types of farming enterprises and on adoption of recommended veld management practices in the region. The main findings from this section are that relatively small farming units with few camps, poor separation of ecotopes and a low estimated grazing capacity, limit extensive livestock farming within the region. Perceptions of farmers on veld condition, grazing rotation, stocking rate, separation of ecotopes are fairly optimistic. As a result grazing capacities are overestimated and overstocking occurs within this region. The current stocking rate in ostrich camps (67.7% overstocked) and mammalian livestock camps (55.1% overstocked) is evidence that farmers overstock to compensate for these limiting factors in order to make a living from the land. The majority of farmers are well aware of the Articles in the Conservation of Agricultural Resources Act of 1983, which are applicable to veld management. Only more that 50% comply with this legislation by rehabilitating veld and 80% of them control invasive alien species on their farm. In the second part, veld assessments were done in randomly selected veld camps, using the multi-criterion, semi-subjective Quick Rangeland Health Assessment (QRHA) Method. Veld condition was significantly poorer closer to water or feeding points due to the piosphere effect caused by livestock. Veld condition in the Little Karoo can be related to altitude, vegetation types and land use. Therefore, the lowlying Little Succulent Karoo vegetation type is in a poorer condition compared to Spekboom Succulent Thicket and South and South-west Coast Renosterveld. Ostrich production on plains in the Little Succulent Karoo vegetation type is the main cause for the degradation of this vegetation type. It would seem as if historically high stocking rates cannot be ignored in explaining the current veld condition. A positive correlation between veld condition and the diversity of plant species (species density) were found, which highlights the importance of good veld management practices in sustainable agriculture. The third part tested whether all indicators in the QRHA method are equally sensitive and whether there is a positive correlation between the QRHA method and the Grazing Index Method. A significant positive linear correlation was found between the two methods. Cover was the least sensitive indicator of rangeland condition, and livestock induced disturbances (which include the indicators grazing intensity, disturbance indicators, soil health and species richness) were the most sensitive for Karoo veld assessment. A major benefit of the QRHA method is heuristic; therefore this method may have value in agricultural extension work.
33

Factors affecting alien grass invasion into West Coast Renosterveld fragments

Van Rooyen, Suretha 03 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: With only 1.76% conserved West Coast Renosterveld remaining it is crucial to prioritize the conservation and management of this fragile vegetation type. Because of its occurrence on fertile soils, renosterveld has been cleared for cultivation and other agricultural use and is thus fragmented to a critical point. These remaining fragments are subject to extensive edge effects and the exact parameters of a viable fragment must still be determined. The extent of alien grass species invasion into remnant renosterveld patches was determined using data collected using the line-intercept method. Sampling included three different management treatment areas adjacent to old lands: 1) a recently burned area, 2) a grazed area and 3) an unburnedlungrazed area providing a control sample. Additionally all small-scale soil disturbances along the lines were recorded. Results showed that Briza spp., Bromus spp. and Avena fatua were the most significant invading alien grass species. There was a significantly high variation between alien grass cover in each treatment, with the grazed area containing the highest overal! level of alien grass invasion. The control area, with the exclusion of fire and animal activity, showed minimum alien grass invasion. Edge effects were apparent in all treatments, but were lowest in the control area, where percentage alien grass cover significantly decreased after a distance of fifteen meters into the remnant patch. A weak positive correlation between the occurrence of alien grass and indigenous grass was found, as well as evidence of a weak association between alien grass cover and shrub cover. The possibility that small-scale soil disturbances could be an important contributing factor to alien grass invasion was supported by the positive correlation between disturbances and percentage alien grass cover. A positive correlation was found between the occurrence of indigenous grass and small-scale soil disturbances, while shrub cover tended to be less associated with animal activity. It is concluded that the correct management regime could effectively control the excessive invasion of alien grass species into the remnant renosterveld patches. Grazing (including all animal activity and small-scale soil disturbances) was the main facilitator of alien grass establishment - even dominating the prominent consequences of edge effects by facilitating alien grass establishment much deeper into the remnant patches. It could be assumed that a precise balance of low-pressure grazing and fire management should be established to enable the effective control of alien grass species while maintaining optimum biodiversity. Keywords: renosterveld, alien grass, grazing, fire, management, small-scale soil disturbances / AFRIKAANSE OPSOMMING: Met slegs 1.76% oorblywende Weskus Renosterveld wat bewaar word, is die beskerming en effektiewe bestuur van hierdie bedreigde plantegroei 'n prioriteit. Die vrugbare grond waarop renosterveld voorkom, het veroorsaak dat dit uitgeroei word om eerder die kultivering van ekonomies produktiewe landbou gewasse moontlik te maak. Dus het renosterveld verminder en gefragmenteer tot 'n kritieke punt. Hierdie ooblywende klein areas bedek met renosterveld, is blootgestel aan ekstensiewe invloede van die omliggende areas en die presiese afmetings vir 'n effektiewe grate renosterveld fragment vir bewarings doeleindes, moel nog vasgestel word. Die male van uitheemse gras spesie indringing in hierdie renosterveld fragmente is ondersoek deur die versameling van data deur die lyn-onderskep metode. Drie verskillende bestuursstelsels vir renosterveld is ondersoek om vas te stel wat die ergste graad van uitheemse gras indringing voorkom. Die studie het 'n 1) onlangs gebrande area, 2) 'n beweide area en 3) 'n kontrole area (wat nie gebrand of bewei is nie) ondersoek. Alle kleinskaalse grond-versteurings langs die lyne is ook aangeteken. Die resultate het aangetoon dat Briza spp., Bromus spp. en Avena fatua, as uitheemse grasse, die belangrikste indringers was en dus die grootste bedreiging inhou. Daar was 'n beduidende hoë variasie tussen die mate van uitheemse gras bedekking aangeteken in elk van die bestuurs-stelsels. Die beweide area het die hoogste graad van uitheemse gras indringing getoon, terwyl die kontrole area (in die afwesigheid van vuur en weidings aktiwiteite) die meeste weerstand teen uitheemse gras indringing getoon het. Die invloed van die omliggende omgewing was ook duidelik sigbaar in al drie die bestuurs-stelsels, maar was duidelik minder in die kontrole area waar die persentasie uitheemse gras indringing aansienlik verminder het na 'n afstand van vyftien meter in die renosterveld fragment in. 'n Swak positiewe korrelasie tussen die voorkoms van uitheemse grasse en inheemse gras spesies was aangeteken, asook bewyse van 'n swak negatiewe assosiasie tussen die uitheemse gras spesies en die inheemse bosse. Soos verwag, is daar bewyse gevind vir die teorie dat kleinskaalse grond-versteurings 'n belangrike fasiliterende faktor is vir uitheemse gras vestiging. Daar was 'n duidelike positiewe korrelasie tussen hierdie grond-versteurings en die persentasie uitheemse gras grondbedekking. Dieselfde positiewe assosiasie was gevind tussen die inheemse gras en hierdie kleinskaalse grond-versteurings, terwyl die inheemse bossie duidelik minder verbind was met die verskynsel. Die gevolgtrekking is gemaak dat 'n korrekte bestuurs-plan die indringing van uitheemse grasse effektief sal kan beheer. Dier aktiwiteite (insluitende beweiding, grawe van gate, mier en termiet neste ens.), en dus kleinskaalse grond-versteurings. was die grootste fasiliteerders van uitheemse gras indringing en vestiging binne hierdie renosterveld stukke. Dit oorheers selfs die aansienlike effek wat invloede van die omringende omgewing op hierdie areas het, deur die uitheemse gras indringing selfs dieper in die fragmente in aan te help. Daar kan dus aangeneem word dat 'n presiese balans tussen lae-intensiteit beweiding (en dus fauna aktiwiteit) en veld brande vasgestel moet word vir die effektiewe beheer van uitheemse gras spesies terwyl die optimum bio-diversiteit terselfde tyd gehandhaafword. Sleutelwoorde: renosterveld, uitheemse grasse, beweiding, vuur, veldbestuur, kleinskaalse grond-versteurings
34

Entre modernisme et avant-garde. Le réseau des revues littéraires de l'immédiat après-guerre en Belgique (1919-1922)/Between Modernism and Avant-garde. A Network of Belgian Literary Journals after World War I (1919-1922) / Tussen modernisme en avant-garde. Het netwerk van belgische literaire tijdschriften onmiddelijk na de eerste wereldoorlog (1919-1922).

de Marneffe, Daphné 11 September 2007 (has links)
Lensemble des revues littéraires « modernistes et davant-garde » parues en Belgique immédiatement après la première guerre mondiale (jusquen 1922) est étudié dans une perspective dhistoire et de sociologie de la littérature. Lexemplification porte principalement sur les corpus des revues bruxelloises (LArt libre, Haro, Au Volant, Demain littéraire et social, Le Geste, Signaux de France et de Belgique, La Lanterne sourde, 7 Arts, Sélection) et anversoises de langue française (La Drogue, Lumière, Ça Ira). Une première partie de la thèse est consacrée à lexplicitation des choix théoriques et méthodologiques. Est dabord étudiée la place réservée à lobjet « revue littéraire » dans différents modèles de sociologie de la littérature (théorie des champs de Pierre Bourdieu, théorie de linstitution de la littérature de Jacques Dubois, études de la sociabilité intellectuelle). Reprenant la terminologie de Christophe Prochasson, lensemble des revues littéraires est appréhendé en terme de « réseau » (tissé entre différents « lieux » et « milieux »). Par sa plasticité, le concept de « réseau » désigne adéquatement lensemble des revues, espace ouvert et aux frontières floues, en permanente reconfiguration, hétérogène et déployé dans la durée. Le « réseau » des revues se développe dans une double dimension humaine (la revue comme lieu de sociabilité, comme milieu) et textuelle (la revue comme lieu de publication, comme instance éditoriale). Une seconde partie de la thèse présente dune part un panorama des revues littéraires belges pendant la première guerre mondiale (revues en Belgique occupée et revues du front) et dautre part la progressive reconstitution de lespace des revues après lArmistice. Dans cette période de transition, les enjeux esthétiques sont inféodés aux questions politiques à propos desquelles se positionnent les revues. Le débat principal (tant politique quarchitectural et littéraire) porte sur la question de la reconstruction du pays, conçue en terme de « restauration » par un pôle conservateur et en terme de « renouvellement » par un pôle moderniste et davant-garde. À travers létude des différentes prises de positions des revues du corpus sont encore abordées les problématiques du pacifisme et de la question flamande, toutes deux au croisement entre littérature et politique. Dans une troisième partie du travail, le réseau interpersonnel et intertextuel des revues littéraires est pris pour objet à travers lexamen des différents lieux et milieux qui le constituent. Létude des différents milieux imbriqués dans les corpus bruxellois et anversois est suivie dun chapitre traitant de questions matérielles concrètes (choix de format, modes de diffusion, financement, types de public visés). Abordées sous cet angle, les revues apparaissent non seulement comme des instances relevant de la vie littéraire, mais aussi comme des instances proprement « médiatiques ». Dans un troisième chapitre sont inventoriés les différents types de lieux où se déploie l« action dart » de ces revues (« centres dart », galeries et lieux dexpositions, tribunes médiatiques, maisons déditions). Le réseau des revues « modernistes et davant-garde » constitue une portion dun continuum plus large : les liens avec les revues et les milieux plus conservateurs sont discrets mais constants, tant sur le plan de limbrication entre les milieux que sur celui des appuis concrets sollicités par les revues « modernistes et davant-garde » pour assurer leurs conditions dexistence. La dernière partie propose un retour sur le modèle réticulaire, notamment sur les questions du déploiement du réseau des revues dans la durée, des enjeux historiographiques et du rapport de la littérature avec les autres champs. En conclusion générale, laccent est mis sur la période de transition de limmédiat après-guerre (1919-1922), où l« effet de réseau » est particulièrement perceptible, et sur lapport de la dissertation concernant les traits définitoires du modernisme et de lavant-garde, en ce qui concerne les revues littéraires.
35

An exploration of risk and protective variables in the bio–psychosocial field of South African adolescents with cystic fibrosis / Hugo C.J.

Hugo, Carina Jacobie January 2011 (has links)
The general aim for this research was to explore and describe the risk and protective variables in the bio–psychosocial field of adolescents with Cystic Fibrosis (CF) and to describe how these variables impact multi–dimensionally on such adolescents. From the literature search it seemed as if interventions regarding CF focus mainly on the medical condition. No literature could be found on the experiences of adolescents with CF. It is clear that there is a dearth of research on adolescents with CF in general but also specifically on the bio–psychosocial impact of this illness on adolescents in this challenging time of maturing. The research design was a case study and focused on exploration and description of risk and protective factors in the bio–psychosocial fields of adolescents with CF. Semi–structured interviews were used as a data collecting method. Questions were open–ended, but focused on the experience of adolescents having CF. Thematic analysis was used for data analysis based on the following steps, which entailed among others transcribing data, reading, re–reading, translation, coding, identifying and describing themes. Facing a chronic illness and the intensive medical treatment required is a harsh reality that influences the entire field of adolescents with CF. This research results expanded knowledge of CF in adolescents within a Gestalt field perspective. Themes identified outline risk and protective factors related to faith, daily routines and especially the effect of medical procedures on time management, emotions, health and body–related aspects, frequent hospitalisation, social support and future concerns. If the risk and protective variables in the field of adolescents with CF is better understood from their own perspective, it is assumed that trans–disciplinary interventions with a multi–dimensional focus will be targeted more accurately in intervention strategies for this vulnerable group. / Thesis (M.A. (Psychology))--North-West University, Potchefstroom Campus, 2012.
36

Investigating adolescents' experiences of using Mxit as a source of peer–support during grade 12 / Kaufman S.

Kaufman, Samantha January 2011 (has links)
The aim of this study is to explore and describe late adolescents' experiences of using Mxit as a source of peer–support during their Grade 12 year in order to provide a broader and more realistic understanding of their support preferences and needs. The classic text of Gestalt Therapy theory in conjunction with current literature provided an overview of the theoretical underpinnings of this study, including the key tenets of Gestalt theory, the core Gestalt theoretical assumptions, Mxit as a social networking application, peer–support and late adolescence. A qualitative research approach with an instrumental case study of eight Grade 12 learners from one public high school in the Northern suburbs of Johannesburg was implemented. The research findings indicated that the affordability, accessibility and non–threatening nature of using Mxit as a source of peer–support made it a viable resource during stressful periods. Although face–to–face peer–support was preferred owing to the limited existential dialogue and lack of trust that was experienced while communicating over Mxit, the adolescents perceived a need for the development of peer–support groups and one–on–one counselling over Mxit as a result of the lack of supportive others experienced during Grade 12 that frequently led to depressive symptoms and/or suicidal thoughts. / Thesis (M.A. (Psychology))--North-West University, Potchefstroom Campus, 2012.
37

An exploration of risk and protective variables in the bio–psychosocial field of South African adolescents with cystic fibrosis / Hugo C.J.

Hugo, Carina Jacobie January 2011 (has links)
The general aim for this research was to explore and describe the risk and protective variables in the bio–psychosocial field of adolescents with Cystic Fibrosis (CF) and to describe how these variables impact multi–dimensionally on such adolescents. From the literature search it seemed as if interventions regarding CF focus mainly on the medical condition. No literature could be found on the experiences of adolescents with CF. It is clear that there is a dearth of research on adolescents with CF in general but also specifically on the bio–psychosocial impact of this illness on adolescents in this challenging time of maturing. The research design was a case study and focused on exploration and description of risk and protective factors in the bio–psychosocial fields of adolescents with CF. Semi–structured interviews were used as a data collecting method. Questions were open–ended, but focused on the experience of adolescents having CF. Thematic analysis was used for data analysis based on the following steps, which entailed among others transcribing data, reading, re–reading, translation, coding, identifying and describing themes. Facing a chronic illness and the intensive medical treatment required is a harsh reality that influences the entire field of adolescents with CF. This research results expanded knowledge of CF in adolescents within a Gestalt field perspective. Themes identified outline risk and protective factors related to faith, daily routines and especially the effect of medical procedures on time management, emotions, health and body–related aspects, frequent hospitalisation, social support and future concerns. If the risk and protective variables in the field of adolescents with CF is better understood from their own perspective, it is assumed that trans–disciplinary interventions with a multi–dimensional focus will be targeted more accurately in intervention strategies for this vulnerable group. / Thesis (M.A. (Psychology))--North-West University, Potchefstroom Campus, 2012.
38

Investigating adolescents' experiences of using Mxit as a source of peer–support during grade 12 / Kaufman S.

Kaufman, Samantha January 2011 (has links)
The aim of this study is to explore and describe late adolescents' experiences of using Mxit as a source of peer–support during their Grade 12 year in order to provide a broader and more realistic understanding of their support preferences and needs. The classic text of Gestalt Therapy theory in conjunction with current literature provided an overview of the theoretical underpinnings of this study, including the key tenets of Gestalt theory, the core Gestalt theoretical assumptions, Mxit as a social networking application, peer–support and late adolescence. A qualitative research approach with an instrumental case study of eight Grade 12 learners from one public high school in the Northern suburbs of Johannesburg was implemented. The research findings indicated that the affordability, accessibility and non–threatening nature of using Mxit as a source of peer–support made it a viable resource during stressful periods. Although face–to–face peer–support was preferred owing to the limited existential dialogue and lack of trust that was experienced while communicating over Mxit, the adolescents perceived a need for the development of peer–support groups and one–on–one counselling over Mxit as a result of the lack of supportive others experienced during Grade 12 that frequently led to depressive symptoms and/or suicidal thoughts. / Thesis (M.A. (Psychology))--North-West University, Potchefstroom Campus, 2012.
39

Some performance characteristics of wooled sheep in the sweet and sourveld communal rangelands of Eastern Cape Province, South Africa

Mvinjelwa, Sivuyile Alex January 2013 (has links)
The objective of the study was to determine sheep growth performance, fleece weights and wool quality characteristics in the sweet and sourveld communal rangelands of the Eastern Cape Province of South Africa. Data were obtained in 80 ewes aged two to three years, selected in four ecologically different communities. Two communities (Roxeni and Tyabane) were in a sweetveld area and the other two communities (Luzi I and Luzi II) were in a sourveld area. The ewes from Tyabane were nondescript, whereas ewes from Roxeni, Luzi I and Luzi II were crossbred between Merinos and non-descript sheep. Selected ewes were monitored for live weight, body condition scoring and fleece weight during shearing. Wool samples were collected from each ewe and were analysed for fibre diameter, comfort factor, clean yield, wool crimps, staple length, staple strength and the Position of break. Sheep from Roxeni were heavier (P <0.05) (39.9 ± 1.1kg) than sheep from Tyabane (29.8 ± 1.1kg). Sheep from Tyabane had the lightest (P <0.05) fleece weight (1.0 ± 1.1kg) and sheep from Roxeni had the heaviest (3.1 ± 1.1kg). There were no significant differences (P ≥0.05) between body condition scores of sheep in Roxeni and the Luzi communities. The live weights of the two-year old ewes were similar (P ≥0.05) to the three-year old ewes’ live weight. However, the three year old ewes had higher (P <0.05) body condition scores than the two year old ewes. Two year old ewes also had lower (P <0.05) fleece weight than the three years old ewes. Wool from Roxeni, Luzi I and Luzi II had lower fibre diameter (P <0.05) than wool from Tyabane. Roxeni sheep had the highest clean yield (P <0.05) of wool, followed by Luzi I and Luzi II; Tyabane had lowest clean yield percentage of wool. Wool from sheep grazing on sweetveld had a higher (P <0.05) clean yield percentage (74.3 ± 0.7%) than those grazing on sourveld (71.7 ± 0.7%). There were higher staple mid-breaks (69.5 ± 5.2) and lower base-breaks (30.5 ± 5.2) in sweetveld (P <0.05) than in sourveld, 7.5 ± 5.2 and 92.5 ± 5.2 for mid-breaks and lower base-breaks, respectively. It was concluded that sheep raised in the sweetveld and bred with purebred Merino rams had higher performance than the ones reared in the sourveld. The young upgraded ewes had a higher wool quality than the older ewes raised on communal rangelands.
40

Assessment and analysis of wildfires with the aid of Remote Sensing and GIS

Vorster, Willem Adriaan 12 1900 (has links)
Wildfires destroy large tracts of veld and forest land every year in South Africa. These fires can be devastating, resulting in loss of human lives, the destruction of property and the loss of income, for example the forest fire in the Sabie district in Mpumalanga in 2007 which destroyed about 7% of South Africa’s forested areas. There are frequently legal disputes with respect to the origin of wildfires, the extent of the fire and the land cover destroyed by the fires. The forensic capabilities of remote sensing in detecting and analysing post-wildfire characteristics have become an important contribution towards solving such legal disputes and in understanding wildfire characteristics. These post fire products can be used as evidence in court cases. Most of the time those court cases came up a few years after the fire event. By then, little or no evidence can be found on the terrain where the fire was. Remote sensing archives provide a reliable source of data that can be used to analyse these events after these long intervals. The objective of this project is to highlight the methods used to generate these post-wildfire analysis products. / Environmental Sciences / M. Sc. (Environmental Science)

Page generated in 0.0451 seconds