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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

Resources overlap and the distribution of grazer assemblages at Telperion and Ezemvelo nature reserves

Deliberato, Henrique Guindalini January 2017 (has links)
A research report submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science. Johannesburg, 2017. / The distribution of grazing herbivores is influenced by several factors, including spatial and temporal availability of resources. The Telperion and Ezemvelo Nature Reserves (TENR), located on the border between Gauteng and Mpumalanga Provinces, experienced a declining hartebeest (Alcelaphus buselaphus caama) distribution over the last years. Simultaneously, an increase in the density of plains zebra (Equus quagga) occurred in the reserves. In this study, I investigated the changes in the distribution of four herbivore species, namely red hartebeest, plains zebra, blue wildebeest and black wildebeest in TENR, and the possible influence that biotic and abiotic factors had on the distribution of hartebeest between 2010 and 2016. Data of aerial surveys conducted in the wet season of each year were used to assess the variation in herbivores distribution along the period. Furthermore, the influence of variables known to affect herbivore distribution (e.g. distance to water, slope gradient, spatial distribution of other herbivore species and vegetation greenness) was tested on hartebeest distribution in TENR. The results indicate that blue wildebeest (Connochaetes taurinus) had the highest distribution variation, while plains zebra presented the most spread distribution among the four species, and black wildebeest (Connochaetes gnou) concentrated their distribution almost entirely at the Ezemvelo nature reserve. Hartebeest avoided areas with the highest concentration of plains zebra, but did not show the same avoidance for areas with prevalence of wildebeest species. Further, high quality forage resources influenced the hartebeest distribution in TENR. Thus, competition for forage resources with bulk feeders may have affected the population and distribution of hartebeest between 2010-2016. / LG2018
2

Level of community participation in the management of the Matsika Grazing Scheme in Limpopo Province

Ramabulana, Mashudu Norman 05 1900 (has links)
MRDV / Institute of Rural Development / See the attached abstract below
3

The effects of sheep grazing on the recovery of succulent Karoo vegetation.

Ross, Jonathan Anthony Genge. January 1995 (has links)
Vegetation monitoring, recording the recovery or change in plant cover over time, for several Karoo shrubs was undertaken to evaluate the Savory Grazing System on a farm in the Succulent Karoo. This evaluation was quantified by establishing if the proposed 120- day rest period between grazing events was sufficiently long enough for complete recovery of the vegetation. Complete recovery was described as sufficient regrowth after a grazing event so that continual cover loss would not result over time. Optimum resting periods would ensure that cover loss, due to grazing, could be recovered so that plant size and reproductive potential was not detrimentally affected. The ellipse intercept method was used to sample piospheres (or zones of attenuating animal impact) around water points in two vegetation types. From these results, 320 line transects for vegetation monitoring were located between 140 and 180m from the water points. One and a half year old piospheres of one farm were compared to seventeen year old piospheres on another farm with similar vegetation composition. The piospheres on the younger farm were expanding at an approximate linear rate of 80m per year, however, this rate slows considerably, as was found on the farm with older piospheres. Stability or equilibrium appears to be reached at approximately 320m from the water point in the older system. The line transects were used to record the change in cover of palatable and unpalatable Karoo shrubs on a monthly basis over an 18 month period. In all instances it was concluded that the proposed 120-day rest period was not sufficiently long enough for complete recovery of the vegetation. The highly palatable species, especially Osteospermum sinuatum and Tetragonia spp., were the most heavily utilized and detrimentally affected. Larger individuals of the palatable shrubs O. sinuatum and Tetragonia spp. were more severely grazed than smaller individuals as a result of smaller individuals utilising spiny nurse plants under which to establish. If the present rest period is continued the result could be overgrazing and local extinction of these important fodder species. The responses of two highly palatable species, O. sinuatum and Tetragonia spp., were monitored closely in relation to rainfall and grazing events. Grazed and ungrazed (protected) individuals were monitored over one year to substantiate the results obtained from the line transects. The rest period was again found to be too short for full recovery and was also found to be reducing the reproductive output of O. sinuatum and Tetragonia spp.. The recruitment of O. sinuatum and Tetragonia spp. was also measured by comparing seedling establishment in grazed, ungrazed (vegetation protected from sheep grazing) and cleared vegetation. In an attempt to rehabilitate these rangelands, Pteronia pallens, a dominant unpalatable shrub, was cleared and the resultant seedling recruitment of O. sinuatum and Tetragonia spp. monitored and compared to grazed and ungrazed vegetation. Juvenile recruitment of these species was found to be significantly lower in the grazed than in the ungrazed vegetation. Recruitment of Tetragonia spp. was found to be significantly higher in the cleared strip compared to the grazed and ungrazed vegetation. The results obtained in this study suggest that the present grazing regime is having a detrimental effect on the vegetation and that revised management procedures are needed to ensure the conservation of these rangelands. The rest periods between grazing events need to be lengthened as well as a reduction in stock numbers. Certain camps need to be skipped on a seasonal basis during the flowering season in order to increase the reproductive output of highly palatable species. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1995.
4

The influence of the composition of mixed Karoo vegetation on the grazing habits of Merino and Dorper wethers

Roux, Francis Augustus January 1994 (has links)
The primary objective of this research project was to determine whether area-selective grazing, by Dorper and Merino wethers, took place in small grazing camps as governed by differences in vegetal cover. The main research techniques employed were the descending-point method for the determination of botanical composition, sub-division of the camps into gridblocks to trace sheep movement in relation to vegetation patterning, fistulated animals to determine diet selection, the electronic theodolite for micro-topography, and few minor techniques. The result have shown that area- patch- and species selective grazing are prevalent in small grazing camps under "normal" stocking densities, and that different breeds of stock (Merino and Dorper sheep) have different grazing patterns and diet selection . Climax and sub-climax areas were those primarily select ed for grazing. There is little or no correlation between botanical composition and diet selected as per fistula ted animal. The average distances travelled by Dorpers and Merinos was 2 km / day and 3.1 km/day respectively. Plant phenology did not have a detectable influence in the choice of diet.
5

Relating vegetation condition to grazing management systems in the central Keiskamma catchment, Eastern Cape Province, South Africa

Ndou, Naledzani Nyahman January 2013 (has links)
Vegetation degradation in South Africa has been identified as a serious environmental problem, especially impacting communal areas. This study investigated the spatial distribution of vegetative condition, along with related changes, deterioration and trends, across the communal villages of the central Keiskamma catchment, Eastern Cape Province. The principal hypothesis of this study was that differences in grazing management strategies may explain the variations in vegetation condition within these communal areas. This investigation assessed the status and condition of vegetation in relation to local institutional grazing management systems, in association with factoring in relevant topographical and physical elements. Topographic homogeneity of the study area was tested by extracting topographic parameters from a DEM and performing a Chi squared test. Remote sensing techniques were used to analyse the spatial and temporal variations in vegetation condition between the villages. Landsat TM images, from 1984 and 1999, in conjunction with SPOT imagery of 2011, were used to assess the spatial trends in vegetation. Land use and cover maps were generated, comprising five categories of land cover, viz. intact vegetation; transformed vegetation; degraded vegetation; bare surfaces; and water. The classification of the images was achieved using the supervised object-oriented classification techniques, which aggregates pixels of each class into homogeneous objects. Information regarding existence and functionality of local institutional structures was obtained through structured interview method. Vegetation condition was correlated to grazing management systems, with the logistic regression confirming a significant relationship between vegetation condition and grazing management systems. Analysis of vegetation condition trends revealed a decline in pristine vegetation with an increase in degraded vegetation and exposed soil throughout the villages. However, it was observed that the decrease in pristine vegetation, with the associated increase in degraded vegetation and soil, do not occur evenly among the villages of the central Keiskamma catchment; the communal areas surrounding certain villages exhibited severe degradation of soil and vegetation, while other villages demonstrated less or minimal deterioration in their environs. The topographic homogeneity of the study locale lent credence to the theory that the uneven distribution of vegetation conditions between the villages is not controlled by topographic factors. Analysis of the data, collected through interviews, revealed differences in the functionality of institutional structures between villages. A statistically significant correlation between the vegetative condition and implementation of grazing management systems, supports the postulated concept that the variances in vegetation condition of the central Keiskamma catchment reflect the efficacy or inefficiency of the settlements‘ grazing management systems. Through gathering, analysing and assessing all the data, a conclusion was drawn, which advances that the primary requirement for remedial action in reversing the current decline in vegetation condition is strengthening the local institutional management regimes throughout all villages under study.
6

Feeding behaviour of Xhosa lop-eared, Nguni and Nguni x Boer goat genotypes kept on rangelands of the false thornveld

Bakare, Archibold Garikayi January 2009 (has links)
Feeding behaviour of Xhosa lop-eared, Nguni and Nguni × Boer goat genotypes kept on rangelands of the False Thornveld By Archibold Garikayi Bakare The study was conducted at the University of Fort Hare farm to assess the feeding behaviour of three goat genotypes: Xhosa lop-eared (XLE), Nguni (NGN) and Nguni × Boer crossbred (NBC) genotypes. The time spent on different activities (grazing, browsing and other activities) on rangelands was recorded using stop watches. The micro-histological faecal analysis technique was used to identify and quantify the plant species that were consumed by the goats across the four seasons. Time spent browsing was high in post-rainy season for XLE (55.94 %) compared to NGN (52.97 %) and crossbred NBC (45.95 %) goats. The high browsing activity was also noted for XLE in hot-wet and cool-dry season (P < 0.05). The NBC goats on the other hand; devoted most of their time grazing compared to XLE and NGN goats across seasons (P < 0.05). Generally, time of day had no effect (P > 0.05) on foraging activities among the goat breeds. Grewia occidentalis, Panicum maximum and Diospyros lycioides were the most preferred plant species by all genotypes across seasons in the paddock. It was concluded that crossbreds spent more time grazing as compared to XLE, which are more of browsers. It could, therefore, be recommended that XLE complement with grazers (cattle and sheep) for efficient management of feed resources in rangelands.
7

Fire-grazer interactions in a Highveld grassland in South Africa

Skhosana, Felix Vusumuzi January 2017 (has links)
A dissertation submitted to the Faculty of Science in fulfilment of the requirements for the Master of Science degree. in School of Animal, Plant and Environmental Sciences, University of The Witwatersrand, Johannesburg July 2017. / Fire is known to affect spatial patterns of grazing by altering the amount and quality of forage. Animals select the post-burn green flush that remains palatable until the grass recovers its biomass. How quickly the grass regrows depends on the rainfall and grass growth rates, and also grazing intensity. Theoretically, highly concentrated grazing can maintain short (relatively more palatable) grasslands throughout a growing season. Therefore this study aimed at; i) determining how long different grazer species were attracted to the burn, and whether this increased grazing pressure (as a result of concentrating grazers on a small burnt patch) maintained a short, palatable grass sward throughout the growing season, ii) investigating the long-term impacts of herbivore attraction to small burns on grass community and landscape function in a Highveld grassland. We therefore monitored grazer utilization of an experimentally applied small (5ha) burnt patch using dung counts and camera traps, and also measured the structural changes of the burnt patch over a period of 12 months. To test whether this process of attraction to small burns could have long-term impacts on grass community composition and landscape function we quantified species composition, infiltration rates, soil compaction, soil moisture, and ANPP in another landscape which had received 10+ years of small annual burns (a firebreak). A novel finding was that indeed grazers especially the short-grass specialist stayed on the burn and kept the grass short (<10cm) for the duration of the study post fire: the burn only treatment on the 5ha burn recovered its biomass within 2 months of the first rains. This result was due to the fact that it was a drought year with half the normal rainfall (and lower grass regrowth rates). However, the long-term study indicated that the attractive effect of small fires in this ecosystem alters both community composition and ecosystem properties. The firebreak had more bare ground and less water infiltration than the surrounding grassland – but was more diverse and had higher grass productivity. It also continued to attract the short-grass specialist species (blesbok, wildebeest and hartebeest). This counter-intuitive result indicates that perhaps these grasslands are not as severely degraded as we think. This study therefore, showed that coupling small burns with appropriate grazer species has a great potential for creating palatable grazing “hotspots”, in sourveld grassland without obvious damage to ecosystem function. / LG2018
8

Grazing sequence pattern and species selection by cattle in the Dohne sourveld

Daines, Thomas January 1976 (has links)
A detailed investigation into the harvesting of the standing grass crop within camps by cattle showed the following: 1. Cattle have a definite order of preference for the components of the Dohne Sourveld grass sward. The most palatable species in order of preference (based on Corrected Species Importance rating) are Themeda triandra, Tristachya hispida, Andropogon appendiculatus, Alloteropsis semialata and Heteropogon contortus. The least preferred species is Elionurus argenteus. 2. The key species, which is defined as the most abundant and productive palatable species, has been identified as Themeda triandra. 3. In harvesting the grass crop, cattle not only have a set preference for species, but also have a set grazing sequence pattern. This can be divided into three main phases. On entering the camp the animals first select the species of their choice, "creaming" these plants (grazed less than 50%) to obtain the most nutritious feed. In their daily search for food they spread their grazing over an increasingly wider area and over a wider range of species. When they can no longer obtain their daily requirements from this "creaming" operation of the more preferred species they return to the most preferred species , which are then heavily grazed (more than 50%) producing the common pattern of area grazing within a camp. These areas increase in size as the cattle graze down the species of their choice, moving to less preferred species as soon as they can no longer obtain their daily intake requirements from the more preferred species. Finally when they have no alternative they graze the least preferred species. 4. Increasing the stocking density does not alter the grazing sequence pattern or change the order of preference for the component species in the sward. It only increases the rate of utilization of the more preferred species and the various phases in the grazing sequence pattern are reached more rapidly. 5. At higher stocking densities the palatable species are more evenly utilized than at lower stocking densities. 6. Cattle graze a greater variety of species when the sward is young and actively growing. As the maturity of the sward increases the cattle concentrate on the more preferred species and are more selective in their grazing. However, their order of preference remains the same. Species that are highly preferred early in the season retain their ranking when the sward is mature. The only exception to this rule is Alloteropsis semialata. Early in the growing season this species is high on the preference list, but as it matures less is taken until when fully mature, it is rejected by cattle. 7. Elionurus argenteus is the least preferred of all the species in the Dohne Sourveld. Cattle will graze this plant as a last resort when grazing a camp early in the season, but reject the plant when it is fully mature. 8. To retain vigour and production of the Dohne Sourveld results of this investigation support the view that grazing management should be based on the principle of controlled selective grazing. Having shown that the more preferred species are over-utilized when attempting to utilize the least preferred species any grazing management that calls for total utilization of all standing vegetation should be rejected. 9. The results of this investigation supports a multicamp system for the Dohne Sourveld where high stocking densities are employed. This will result in the rapid and even utilization of the more preferred species. Management should be based on short period of stay and long period of absence. Cattle should be moved as soon as the key species have been well utilized, but not overgrazed. Cattle should only be returned to the camp when key species have made adequate regrowth following grazing. 10. A method, that is simple to use, is proposed for determining utilization of the veld and key species at different times of the year using the relationship between percentage of ungrazed plants and utilization of the sward and of Themeda triandra, the key grazing species in the sward. 11. Results show that when rested camps are grazed after May, the number of Themeda triandra inflorescences are drastically reduced. Veld that is specifically rested for the production of Themeda triandra seed should be rested from March of the year preceding expected seeding.
9

The importance of browse in late dry season and early wet season diets of cattle and goats in a communal area of the Eastern Transvaal lowveld

Davies, S. J. January 1993 (has links)
A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science. Johannesburg, 1991. / The contribution of browse and grass to the diets of cattle and goats was assessed in relation to the total biomass of woody foliage and grass available in the study area. Livestock made less use of browse during the dry season than was shown by studies conducted in the Sahel and Nylsvley, northern Transvaal. Goats fed more selectively, utilised newly flushed foliage more and fed upon a greater variety of woody plant species than did cattle. Browse contribute nore to goat diets than to cattle diets although goats were less often supplied with browse. For goats, feeding on standing browse, 'supplied browse and leaf litter occupied 34.7 % of observation time before the tree/shrub flush and 8.3 % post-flush; for cattle the contributions were 14.7 % and 5.8 %, respectively. Fruits, flowers and bark were utilised only during the pre-flush period and only by goats. Goats spent significantly more time grazing and more time browsing than did cattle during the post-flush period. Agave sisalana (sisal) contributed to cattle diets during the preflush and post-flush periods, and to goat diets during the pre-flush period. Since relatively little standing woody foliage is accessible to the animals (16.6 % preflush and 30.7 % post-flush of the wet season maximum), lopping of woody foliage by herders substantially increases the amount of food accessible to livestock, and supplied browse was eaten wherever it was encountered. Aerial cover of grass averaged less than 20 %, grass biomass ,less than 120 kgDM.ha·t and biomass concentration of grass less than 553.5 gDM.m"3 for catena toplands, catena bottomlands and drainage line thickets. The low contribution of browse to livestock diets during this study was due to the scarcity of accessible, palatable forage, exacerbated by the late flush 011 woody plants. In addition, local people harvesting live wood for fuel may compete with foraging livestock. To increase the supply of food for livestock further the rollowing practices could be encouraged: storage of woody foliage litter until the late dry season, use of chemicals to increase the nutritional value of poor quality browse and establishment of woodlots of palatable, perhaps leguminous, evergreen woody species for use as livestock fodder. / GR2017
10

Weidingsbestuur in 'n semi-ariede omgewing met GIS : Paulshoek gevallestudie

Combrink, A. P. (Adrian Peter) January 2004 (has links)
Thesis (MSc)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: Grazing management in the semi-arid communal areas of Namaqualand is investigated in this study. Paulshoek, situated in the Leliefontein Communal Reserve area, is delineated as the study area and consists of 20 OOOha.Cattle farming is practised by most households primarily on a subsistence basis. It is also used as a source of income when financial problems arise. The management of grazing-land in terms of formal rules and regulations is non-existent with only mutual relationships between farmers. The aim of this study is to develop a spatial framework for the management of a sustainable grazing regime with the aid of Geographic Information Systems (GIS) technology. This aim is reached through three overlapping goals which are researched individually. The goals are to create a spatial image of the physical resource base as well as resource usage and from this the development of a computerised (Excel spreadsheet) spatial management framework for sustainable grazing management. Through the use of existing data available from the National Botanical Institute (NB!) as well as other sources and with the aid of GIS technology, coupled with Indigenous Knowledge, these goals were reached. The stockpost as individual entity is studied to give a broader understanding of how the herdsmen see their immediate environment. The grazing management system, as presented in this thesis, consists of a simple Excel Spreadsheet, with inputs from GIS technology and Indigenous Knowledge. The area is overgrazed, as is seen in the widespread occurrence of kraalbos cross the Paulshoek landscape. The recommendations are that this management system should be implemented, which could minimize the futher overgrazing of the area. The management system relies heavily on the cooperation of the community and the integration of existing management systems and policies. It will give a more detailed account of who may own how many stock and where they may graze in the communal rangelands which will also help in the establishment of new permanent waterpoints in the area. / AFRIKAANSE OPSOMMING: Weidingsbestuur in die semi-ariede gemeenskaplike gebiede van Namakwaland is in hierdie studie ondersoek. Paulshoek, geleë in die Leliefontein Gemeenskapsreservaat gebied, word as studiegebied afgebaken en beslaan ongeveer 20 OOOha.Veeboerdery word deur meeste van die huishoudings primêr as bestaansboerdery beoefen. Dit word ook gebruik as 'n bron van inkomste wanneer finansiële probleme ondervind word. Die bestuur van weivelde in terme van formele reëls en regulasies is glad nie ter sprake nie, slegs onderlinge verhoudinge tussen veeboere bestaan. Die doel van hierdie studie is om 'n ruimtelike raamwerk te ontwikkel vir die bestuur van 'n volhoubare weidingsregime deur die aanwending van Geografiese Inligting Stelsels (GIS). Hierdie doel word behaal deur drie oorkoepelende doelwitte wat elk afsondelik behandel word. Die doelwitte is om 'n ruimtelike beeld van die fisiese hulpbronbasis asook die benuttingsregime van die hulpbron te skep, en hieruit 'n rekenaar-gesteunde (Excel sigblad) ruimtelike bestuursraamwerk vir volhoubare weidingsbestuur te ontwerp. Deur gebruik te maak van bestaande inligting afkomstig vanaf Nasional Botaniese Instituut (NBI) asook ander bronne en met die koppeling van GIStegnologie en Inheemse Kennis (IK) is die doelwitte bereik. Die veepos word as entiteit behandel om 'n beter verstandhouding op te bou van hoe die veewagter sy onmiddelike omgewing bestuur. Die weidingsbestuurstelsel, soos voorgestel in hierdie tesis, bestaan uit 'n eenvoudige Excel sigblad, gekoppel aan GIS-tegnologie en Inheemse Kennis. Die gebied is oorbeweid, soos gesien kan word aan die verspreiding van kraalbos regoor die landskap van Paulshoek. Die aanbevelings is dat die bestuurstelsel geïmplementeer moet word om te verhoed dat die gebied verder onderhewig sal wees aan intensiewe beweiding. Die bestuurstelsel berus op die samewerking van die gemeenskap en die integrasie van bestaande bestuurstelsels. Dit sal tot gevolg hê 'n meer volledige opname van wie hoeveel vee mag besit en wie waar mag vestig in die weiveld gebied, wat gevolglik ook die skepping van nuwe permanente waterbronne sal vergemaklik.

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