• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 7
  • 3
  • Tagged with
  • 10
  • 10
  • 7
  • 6
  • 6
  • 6
  • 5
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 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

The effect of genetic improvement, fertilisation, weed control and regeneration method on the establishment and performance of Eucalyptus macarthurii and Eucalyptus nitens.

Van den Berg, Gerhardus Johannes. January 2005 (has links)
Eucalyptus grandis was introduced into South Africa in the 19th century, and has since become the most important of the hardwood plantation tree species grown for pulp. Until the late 1980's E. grandis was virtually the only eucalypt species grown. In order to meet the increasing demand for pulpwood in South Africa, forestry companies need to increase their timber output from an existing land base (Brown and Hillis, 1984; Kimmins, 1994 and Little and Gardner, 2003), or alternatively extend the planting of favourable alternative tree species into areas previously considered unsuitable for forestry due to unfavourable climatic conditions. From 1984 the major timber companies expanded their plantation forestry into the colder, frost-prone highland areas of western KwaZulu-Natal, the northeastern Cape and southeastern Mpumalanga Highveld. As E. grandis was not tolerant to severe frost, E. macarthurii amd E. nitens were planted in these areas as alternatives (Schonau and Gardner, 1991). As much of the earlier research had been centered around the development of silvicultural standards for E. grandis, it became necessary to test these for the different eucalypt species. Two trials were therefore established to E. marcarthurii and E. nitens with the following objectives: - to extend current recommendations to include different species, - to determine the degree of interaction between different silvicultural standards (genetic improvement, fertilisation and weed control), - to determine the effects of weeds, fertilisation, genotype and regeneration method (seedling vs coppicing) on the initial and long term growth, uniformity, tree straightness and survival of cold tolerant eucalypts, - cost effectiveness of various methods for re-establishing E. nitens and E. macarthurii. Genetic improvement played an important role in the establishment and initial growth of E. macarthurii and E. nitens. The improved treatments outperformed the unimproved treatments in terms of tree growth until canopy closure. At the last measured date when the trees were six years of age, the E. nitens improved seedlings were still significantly better in terms of basal area when compared to unimproved seedlings. The initial positive effect of genetic improvement of E. macarthurii seedling however, was not sustained. Genetic improvement of E. macarthurii and E. nitens also had a positive effect on tree straightness and survival when the trees were assessed at five years of age. The genetic improvement of both species also showed to be a viable option to produce an optimum timber output at a lower cost when regeneration is carried out by means of replanting with seedlings. Fertilisation also showed positive effects in terms of the establishment and initial growth of E. macarthurii and E. nitens. At six years after planting, the basal area of E. macarthurii seedlings without fertiliser was still significantly lower than any one of the other treatments. However, the initial positive effect fertiliser had on the growth of E. nitens seedlings decreased to a non-significant level at six years after planting. Fertilisation of E. macarthurii and E. nitens had a positive effect on tree straightness and survival when the trees were assessed at five years of age. The fertilisation of E. macarthurii seedlings also produced an adequate amount of timber at a relatively low cost. The controlling of weeds did not have an impact on tree performance initially or after canopy closure for either E. macarthurii or E. nitens. This is due to the lack of weed growth at these high altitudes at which the sites were planted. Little and Schumann (1996) found that eucalypts could tolerate an aboveground weed biomass of up to 2000 kg ha (-1) before there were any severe losses in growth due to competition. At both these trials, the weed load did not reach these levels in order to compete with the trees. No significant interactions between any of the treatments were detected at both these sites at any stage. At the last measured date, there were no significant differences in terms of tree growth between the coppice and seedling treatments for either E. macarthurii or E. nitens. Regeneration by means of E. macarthurii and E. nitens coppice had a positive effect on tree straightness and survival when the trees were assessed at five years of age. Re-establishment by means of coppice for both E. macarthurii and E. nitens was also shown to be by far the most cost-effective way at present to produce an adequate amount of timber. Coppicing was shown to be the least costly way to produce a m2 ha(-1) of timber provided the right species are coppiced, and optimum density levels are obtained. / Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.
2

Evaluation of tree performance, site conditions and silvicultural procedures in forest plantations at high altitude sites in Lesotho.

Pama, Mokete M. January 2005 (has links)
The permanent sample plots (PSP) and silvicultural trial plots established by the Forestry Research Section of the Forestry Department of the Ministry of Forestry and Land Reclamation in Lesotho were used as a source of information for this study. The study area is located in the forest plantations on high altitude sites in Lesotho which have the aim to determine important aspects of timber production for commercial use and to address the problem of fuel wood scarcity and energy crisis. The major objective of the study was to describe performance (survival, growth and timber volume) of exotic tree species introduced in Lesotho. The height and diameter relationships for trees in the 33 plots of Eucalyptus rubida and 44 plots of Pinus radiata were determined by a simple linear regression. There are four plots of Eucalyptus macarthurii, three plots of Pinus halepensis, one plot of Eucalyptus nitens and one plot of Pinus pinaster. The permanent sample plots data were analysed with the use of a statistical package Genstat (7th edition). Categorical analysis were used to detect the number of live and dead trees. The correlation analysis was used to study association between site and performance variables, while multiple regression analysis was utilised to analyse relationships between site index and site variables. The growth curves developed for E. rubida and P. radiata tended to indicate a sigmoidal shape. Analysis of variance was utilised to analyse the performance of species in terms of survival and growth (HT and DBH) for the four species and provenance trials. The early mortality rate was 2% for E. macarthurii, 14% for E. rubida, 0% for E. nitens. Later, it was found that the percentage of dead trees is as follows: 7% for E. macarthurii, 15% for E. rubida, 29% for E. nitens. It was detected that the mortality rate for eucalypts was 14% at last assessments. Similarly, it was detected that the final mortality rate for P. halepensis, P. pinaster and P. radiata was 2%, 19% and 20% respectively. The mean diameter for P. radiata ranged between 1,87 cm at age 3,75 years and 24,49 cm at age 18 years. The mean height ranged from 1,51 m at age 0,75 yrs and 13,51 m at 16 years. It was discovered that the mean diameter is found between 8,0 cm at age 4,83 yrs and 14,41 cm at age 8,83 yrs for P. halepensis. The mean height was 2,1 m at age 4,83 years and 16,48 m at age 13,50 years. The mean diameter ranged from 7,41 cm at age 6,42 years and 15,92 cm at age 10,42 years for P. pinaster. Similarly, the mean height was detected to be between 5 m at age 6,42 years and 7,75 m at age 12,42 years for P. pinaster. It was noted that the mean diameter for E. rubida ranged from 2,04 cm at age 2,25 years to15,87 cm at age 11,75 years. On the same line the mean height started at 4,55 m at age 2,42 years and ended at 16,15 m at age 11,75 years. The mean diameter for E. macarthurii was noted to be 13,64 cm at age 10 years. It was noticed that mean height is found between 3,8 m at age 2,17 years and 16,03 m at age 10 years. It was also detected that the mean diameter started from 4,45 cm at age 2,50 years and 10,78 cm at age 6,50 years for E. nitens. The mean diameter ranged from 5,98 cm at age 2,50 years and from 12,05 m at age 6,50 years for E. nitens. The mean annual increment (MAI) for P. radiata is found between 0,15 m3/ha/yr at age 2,25 years and 21,91 m3/ha/yr at age 6,50 years. The MAI ranged from 0,58 m3/ha/yr at age 3,42 years and 10,81 m3/ha/yr at age 10,42 years for E. rubida. It was determined that the MAI started from 0,25 m3/ha/yr at age 2,17 years to 9,99 m3/ha/yr at age 4,17 years for E. macarthurii. The MAI started from 1,59 m3/ha/yr at age 2,50 years and to 7,54 m3/ha/yr at age 6,50 years for E. nitens. It was noted that the MAI for P. halepensis began from 0,01 m3/ha/yr at age 4,83 years and 3,52 m3/ha/yr at age 13,50 years. Similarly, the MAI began from 0,73 m3/ha/yr at age 6,42 years and 2,70 m3/ha/yr at age 10,42 years for P. pinaster. The Site indices for E. rubida and P. radiata were calculated. They ranged from 6,72 to 14,40 m and from 12,05 to 18,43 m for E. rubida and P. radiata at age 6 years and 15 years respectively. The MAI and SI of different species justify that a viable commercial forestry can be implemented in Lesotho, if advanced selection of genetic material, improved silviculture and appropriate site species matching can be followed. It was noticed that various silvicultural practices like proper land preparation methods, weed management and deep planting have a large impact on tree performance. Based on these results, larger afforestation projects for commercial timber production and bioenergy are recommended. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.
3

The development of a wall-less plug for planting stock of forest trees.

Schuermans, Jean. 14 November 2013 (has links)
High output commercial nurseries that cater for the forestry industry are continuously challenged to efficiently and cost effectively produce good quality planting stock to establish large plantations. Currently, South African commercial nurseries produce planting stock in solid compartmentalized trays. One of the major drawbacks of these containers is the susceptibility of trees to root deformation following outplanting, combined with the need for the return of empty containers to the nursery. A potential solution to these challenges is the introduction of wall-less plugs for the production of planting stock. Wall-less plugs are volumes of growing medium, usually cylindrical in shape, devoid of an impenetrable wall in which a plant can grow and establish itself. Such plugs may enable the production of planting stock with improved root systems, without the need for the return of empty containers after outplanting. In this research four prototypes of wall-less plugs were developed, produced on a small scale and tested. These were: 1) Paper-maché plugs made using the original WRIBLOK protocol whereby composted pine bark was bound together with repulped newspaper, 2) Sponge blocks, 3) Hessian bags and 4) Covetan bags. The performance of these prototype wall-less plugs was compared with the performance of four tray types used commercially by the forestry industry: 1) Poly 128 shallow, 2) Poly 98 deep, 3) Unigro 128 and 4) Sappi 49. These are polystyrene and polypropylene-based containers. Of these containers the Unigro 128 and Sappi 49 containers were of similar performance. Performance in terms of height and root collar diameter increase over ten weeks from the time of sowing of the paper-maché plugs was similar to that of the Unigro and Sappi 49 containers. The sponge block, Hessian bags and Covetan bags produced inferior quality planting stock compared to the other treatments tested. Although little progress was made in the ability to describe how one root system differs from another in terms of their branching patterns, a technique was developed to determine root surface area by image analysis software that is freely available. This method may prove useful for further research and for determining seedling quality in commercial nurseries. / Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.
4

Factors affecting the successful deployment of Pinus patula as rooted cuttings.

Mitchell, Richard Glen. January 2005 (has links)
Summary: The future mass propagation of elite families of Pinus patula by cuttings is a realistic method of deployment if the short-term performance of cuttings and seedlings are confirmed at harvesting. This will impact significantly on the future outlook of forestry in South Africa as softwood yields are improved substantially through the introduction of material of high genetic value in commercial plantings. This, however, will require significant changes in future silviculture and other management practices as foresters and plantation staff learn to regenerate, maintain, and schedule the harvesting of cutting stands according to a different set of demands as a result of the change in plant type. Contrary to operational experience, cutting survival was similar to seedling survival in all field studies. This indicates that factors other than those that were studied and reported on, such as planting techniques, may be contributing to mortality. Also, due to the different root structure of cuttings they may be more fragile. The similar survival observed in these trials, therefore, may have been due to the close supervision given to the planting operations by the research staff. Although survival was similar, both plant types survived unacceptably poorly in the majority of studies with an average stocking of approximately 50% at one year. It is therefore anticipated that commercial stands will require several blanking operations in order to achieve an acceptable stocking in excess of 85% by the following planting season. The reduction in expected profitability as a result of blanking costs, delayed establishment, and the loss of improved genetic plant material, indicates that this is an area that still requires further research irrespective of what plant type is being planted. The pathogen, Fusarium circinatum, was commonly isolated from the planting stock before and after planting in two studies. Due to its virulent nature, it was assumed that mortality on the trees on which F. circinatum was isolated was principally due to this pathogen. At planting all plants were observed to be healthy and free of disease indicating that this pathogen maybe carried from the nursery to the field in a cryptic form, either inside or outside the plant tissue , which results in the death of the newly planted tree. In two field studies, where F. circinatum was commonly isolated, the application of Benomyl fungicide and to some extent the biological control agent Trichoderma harzianum at planting appeared to improve survival although this improvement was not significant. Laboratory studies, designed to determine alternatives to Benomyl fungicide, indicated that three fungicides (Octave, Folicur and Tilt), three sterilants (Sporekill®, Prasin®and Citex®) , as well as a biological control agent (T.harzianum), were all highly successful in controlling F. circinatum colony growth in vitro. It is recommended that these products undergo nursery testing , where the plant material is inoculated with F. circinatum spores, in order to test their efficacy and possible phytotoxicity in vivo before commercial application. Post-planting survival was also affected by site climate . Greater temperature extremes, as well as lower humidity and less rainfall resulted in poor survival. Plant dimension at planting was found to interact with site quality where it was a significant factor on a poor quality site. Optimal cutting dimensions at planting was a root collar diameter of 2.8 - 3.2 mm, and a stem height greater than 7 cm at planting for cuttings produced in cavities 90 ml in volume. Optimal seedling dimensions at planting were a root collar diameter of 1.8 - 2 mm, and a stem height of 10 - 15 cm for seedlings produced in cavities 80 ml in volume. In a separate study, plant morphological criteria influenced medium-term growth, where greater root mass and thicker cutting root collar diameters at planting improved field growth performance for seven years after planting. A greater root mass at planting was achieved by raising cuttings in containers that could support greater medium volume. From the study it was concluded that cuttings should be raised for an approximate period of 9 months in container cavities no smaller than 80 ml in volume and possess an oven-dry root mass of 0.3 - 0.5 g at planting. In addition to similar survival, the cuttings in this study grew either similarly to, or in some cases out-performed, the seedlings that were used as a control. Several other published studies indicate that hedge maturation poses the greatest threat to the success of softwood cutting deployment. This is especially true in clonal forestry and methods to maintain juvenility, such as cold storage of shoots and cryopreservation, require further research before clonal plantations of P. patula can be realised. In the studies carried out on family hedges in this report, the effect of donor hedge maturation was found to influence nursery management practice and the characteristics of rooted cuttings. The nursery data indicates that rooting efficiency, root system quality, and stem size and form, all decline with increasing hedge age particularly from two years after the date of sowing. A decline in root system quality was particularly apparent and was observed prior to a decline in rooting efficiency. If field trials indicate poorer performance from older hedges , it may be necessary to determine whether the causes are purely ontogenetic, morphological, or both before drawing final conclusions about hedge longevity. Until such results are known, it is recommended that P. patula cuttings should be propagated from seedling donors maintained as hedges , approximately 15 cm high, for a period not more than three years from the date of sowing. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.
5

Parameterisation of the 3-PG process-based model in predicting the growth and water use of Pinus elliottii in South Africa.

Sithole, Zola. 04 November 2013 (has links)
A simplified process-based model simulating growth and water use in forest plantations was utilised to predict the growth of Pinus elliottii in South African forest plantations. The model is called 3-PG (Physiological Principles in Predicting Growth) and predicted the growth of trees by simulating physiological processes that determine growth and water use, and the way trees are affected by the physical conditions to which they are subjected, and with which they react. Pinus elliottii growth data recorded in 301 sample stands around South Africa were sourced from forestry companies. A selection procedure reduced the number of stands to 44, where 32 were used to parameterise 3-PG and 12 were reserved for testing the final model parameters. This was accomplished by matching model output to observed data. All stand simulations were initialised at age four years and continued to the maximum age of recorded growth. A provisional set of parameter values provided a good fit to most stands and minor adjustments of the specific leaf area (σ), which was assigned a value of 5 m2.kg-1, were made, bringing about an improved fit. The predictions of mean DBH, Height, and TPH were relatively good, achieving R2 of 0.8036, 0.8975, and 0.661 respectively, while predictions of stem volumes were worse (R2 =0.5922, n=32). The 3-PG model over-predicted DBH in 20 stands, while modelled volume predictions improved substantially in thinned stands (R2 =0.8582, n=14) compared to unthinned stands (R2 =0.3456, n=18). The height predictions were generally good producing an R2 =0.8975. The final set of 3-PG parameter values was then validated against growth data from the 12 independent stands. The predictions of mean DBH, Height, and TPH were relatively good, achieving R2 of 0.8467, 0.7649, and 0.9916 respectively, while predictions of stem volumes were worse (R2 =0.5766, n=12). The results of this study demonstrated the potential for 3-PG to respond to many growth factors and to predict growth and water use by trees with encouraging realism. Patterns of changing leaf area index (L) over time, responses to drought, and annual evaporation patterns all look realistic. Consequently, 3-PG is judged to have potential as a strategic forestry tool. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.
6

Ecotourism for sustainable development : economic valuation of recreational potentials of protected areas in the Congo Basin.

Tieguhong, Julius Chupezi. January 2008 (has links)
This study was designed to capture the complexity of man-to-forest relationships in the endangered, world-renowned tropical rain forests of the Congo Basin in Africa. Their biological complexity and integrity have been challenged by human development and new knowledge is urgently needed to save these forests and the people dependent on them. The scope of the study was enormous because of the complexity of the resource, the diversity of forest-dependent people and actors. The major benefit of this research was in accessing and exposing new and quantitative information in remote settlements of the region by applying innovative methodologies and analytical techniques. These included: 1. The definition of forest-dependency based on detailed annual inventories of sources of households’ incomes, their statistical ranking and interpretation with logistic regressions, and the Kuznets ratio and Gini coefficients as introduced by the World Bank; 2. critical appraisal of the international parks in the region based on auto-financing principles and tested with contingent valuation and tax maximization techniques, such as Laffer’s curves, and leading to the development of new conservation models of financial self-sufficiency and a new formula for practical park management; 3. the critique of poaching by explaining and exposing food insecurities, especially deficient supplies of animal protein and associated malnutrition among the rural poor; 4. assessment of housing inadequacy among forest dwellers and its impact on forest regeneration and resources; 5. clarification of the impacts of timber logging by accessing detailed unpublished information from timber companies; 6. the introduction of survey-based valuation techniques as essential prerequisites to policy formulation and the sustainable management of forests; 7. proposing a flow chart that embraced the resources and stakeholders through the flow of market values and services for further exploration. Contrary to traditional beliefs; the results showed that both poor and wealthy households are equally dependent on forest resources for their livelihoods with no significant difference in consumed forest products between the 25% higher income earners and the 25% lower income households. Forests contribute over 57% of wage income in the region and forest-derived income is of a higher total value than any other source, including agriculture. Among forest foods, wild fruit and bushmeat are by far the most important. Therefore, the clearing of forests for agriculture or instituting conservation policies that completely keep local people away from forests will result in constrained access to resources of immense importance to local livelihoods. However, the findings contradict the commonly propagated views that timber harvesting in the region is directly responsible for deforestation, the loss of forest structure and biodiversity. It was shown that the harvesting of saplings and poles for housing may endanger forest regeneration and species composition of forests neighbouring the villages. The desired financing of national parks should be through internally generated revenues, requiring deliberate investments in facilities and infrastructure. The necessity to satisfy the basic needs of the forest-dependent people remains urgent. The complexity of man-to-forest relationships is beyond one study and needs to be further expanded on, in our quest to sustainable forest management based on participatory principles. Such management needs to provide for and be supported by various stakeholders including the local communities, state agencies, donors, NGOs, and commercial conglomerates. Moreover, the need to understand forest values beyond market principles is required in order to translate the concept of sustainable forest management from a theoretical concept in the Congo Basin to one that can reduce conflicts, deforestation, poverty and famine.
7

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.
8

Developing a non-destructive screening tool for pulp yield in Acacia mearnsii (Black wattle) / Developing a non-destructive screening tool for pulp yield in Acacia mearnsii (Black wattle)

Dunlop, Robert William. January 2009 (has links)
Acacia mearnsii (black wattle) is an important South African commercial forestry species, providing a source of high quality raw material (fibre) for both the domestic and international pulp and paper industries. Compared with many Pinus and Eucalyptus species, there has been very little research into the wood and pulping properties of black wattle. The ability to assess pulp yield in a non-destructive manner, using near infrared (NIR) spectroscopy, is vital from a tree improvement perspective. Destructive sampling and analysis, results in the loss of the genotype, while also being very expensive and time consuming. In order to assess some of the important characteristics that make the species desirable from a fibre perspective, this study investigates growth characteristics, wood density and pulp yield of ten trees grown on each of three different sites namely, Bloemendal, Glen Echo and Phoenix, and from each of three different age classes being 7- , 9- and 11-years-old. In total, 90 trees were sampled for this stage of the study. In general, physical characteristics such as utilisable height and diameter at breast height of the trees differed between sites and increased with age, this age effect trend was not reflected in the pulp yield or wood density results. Pulp yield measurements ranged from 52.61 to 59.91% across all sites and age classes, which, when compared to the pulp yield from many other forestry species, is relatively high. Laboratory pulp yield data was used in conjunction with NIR spectra obtained from the same wood samples to calibrate a NIR spectrophotometer to predict pulp yield. Thirty 11- year-old trees were then chosen from the Bloemendal site and sampled extensively to investigate the within-tree variation in pulp yield. The NIR model developed was used to measure the pulp yield from the numerous samples taken from within the trees. In general, pulp yield decreased from pith to bark and from the base of the tree to about 20% of the tree height and then decreased towards the top of the tree. The within-tree variation data for pulp yield was analysed to identify the best position for non-destructive sampling, and a model was then developed to predict whole tree pulp yield based on this sample, which was taken at 1.4 m up the tree. The analyses of small samples of wood meal, using near infrared spectroscopy, enabled the prediction of whole tree pulp yield. / Thesis (M.Sc.) - University of KwaZulu-Natal, Pietermaritzburg, 2009.
9

Camelthorn (Acacia erioloba) firewood industry in Western Cape, South Africa

Raliselo, 'Muso Andreas 04 1900 (has links)
Thesis (MFor)--University of Stellenbosch, 2003. / ENGLISH ABSTRACT: The reliance of firewood demand on indigenous trees such as Acacia erioloba is a continuing phenomena despite the concern that over-exploitation of these resources will degrade the environment. This study tested the hypothesis that the cutting of A. erioloba in the Northern Cape is driven by (a) market demand in the Western Cape, (b) ignorance of the long-term ecological consequences and/or (c) ignorance of legislation along the chain of custody of this product. The assumption is that whoever is involved in the A. erioloba firewood industry (resource owner, trader or user) is neither aware of the protected status of the resource nor the negative consequences associated with the over-exploitation of the resource or they are driven by short term monetary gains. Therefore, there is a need to understand the needs of every participant in the chain and to further find out if there may be substitutes for A. erioloba firewood. The results of this study show that there is a market for firewood in the study area and that this demand is driven mainly by the availability rather than the quality of firewood. It will also be shown that Acacia mearnsii which is available in the study area is a better product than A. erioloba and therefore it can be a suitable replacement but consumers were found to bum almost everything that would give them embers. The most preferred firewood in the study area is A. cyclops. The concept of indigenous trees is not clearly understood by retailers and consumers. The major role players in the supply chain were found to be the retailers and the transport owners who may be targeted when firewood trade is to be stopped in the short-term. The results further highlighted the fact that the majority of consumers were aware that indigenous trees were protected in South Africa but the majority of retailers were not aware. The study recommends that firewood trade should be stopped completely by strict enforcement of the law or by the involvement of every role-player and/or that the trade should be regulated. / AFRIKAANSE OPSOMMING: Die fenomeen dat die aanvraag vir vuurmaakhout staatmaak op inheemse bome soos Acacia erioloba duur steeds voort ten spyte van die kommer dat oorbenutting van hierdie hulpbronne, ter versadiging van die behoeftes van 'n steeds toenemende populasie, die omgewing sal degradeer. Hierdie studie het die hipotese getoets dat die afsny van A. erioloba in die Noord- Kaap aangedryf word deur (a) die mark aanvraag in die Wes-Kaap, (b) onkunde oor die langtermyn ekologiese gevolge en/of (c) onkunde oor die wetgewing van hierdie produk by die skakels in die verskaffersketting. Die aanname is dat wie ook al betrokke is by die A. erioloba vuurmaakhout-industrie (hulpbron eienaar, handelaar of gebruiker) is beide onbewus van die beskermde status van die hulpbron asook van die negatiewe gevolge geassosieer met die oorbenutting van die hulpbron of hulle is aangedryf deur korttermyn monetêre gewin. Daarom is dit nodig om die behoefte van elke deelnemer in die ketting te verstaan en om verder uit te vind of daar plaasvervangers vir A. erioloba vuurmaakhout is. Die resultate van hierdie studie toon dat daar 'n aanvraag is vir vuurmaakhout in die studie-area en dat hierdie aanvraag hoofsaaklik gedryf word deur die beskikbaarheid, eerder as die kwaliteit van die hout. Daar salook aangetoon word dat Acacia mearnsii, wat in die studie-area beskikbaar is, 'n beter produk is as A. erioloba en dus 'n geskikte plaasvervanger kan wees, maar dit wil voorkom of die verbruikers omtrent enigiets sal brand wat kole sal verskaf. A. cyclops is die vuurmaakhout van voorkeur in die studie-area. Handelaars en verbruikers verstaan nie die konsep van inheemse bome duidelik nie. Die vernaamste rolspelers in die verskaffersketting is die handelaars en die eienaars van die vervoer en hulle kan die teikengroep wees as die handel in vuurmaakhout in die korttermyn stopgesit word. Die resultate het verder na vore gebring dat die meerderheid verbruikers daarvan bewus is dat inheemse bome beskermd is in Suid-Afrika, maar die meerderheid handelaars is nie hiervan bewus me. Hierdie studie maak die aanbeveling dat handel in vuurmaakhout totaal gestaak moet word deur strenger wette of deur die betrokkenheid van elke rolspeler en/of dat handel gereguleer moet word.
10

The impact of urban expansion and population growth on productivity of forestlands : study area: Rustenburg Local Municipality.

Seokwang, Modise. January 2007 (has links)
The survey has been carried out in North West Province within Rustenburg Local Municipality. This is an Urban Forestry research in which six sites including peri-urban, urban, suburban and semi-rural areas were selected for the study. The aim of the study was to determine the relationship between households and their local trees and forests. Forest in this context included community gardens, vegetation cover, open spaces, soil, water, productive sites and animals that form part of forest. Data collection was mainly based on questionnaires and covered sample of 272 households. Statistical Package of Social Sciences (SPSS) 15.0 using 5% sampling intensity (confidence level) was used in which the data has been represented by numbers. Analysis was based on determining households’ relationship with their trees and local forest, and how they influence forest productivity or development. With SPSS two techniques, regression model and descriptive statistics were applied to analyze quantitative and qualitative data. Regression model was significant in prediction of the dependent variable (Y) using independent variables (X), and proved to be a good model to analyze data for fuelwood, timber and forest food production. Descriptive statistics was important in counting number of times each category or variable is used. Participants had varying perceptions regarding the use of forest due to factors such as availability of forest resource, type of residence, and their living standard. Generally, households in suburban and urban areas value the forests for economic and environmental benefit, while the peri-urban and semi-rural households utilized their trees and forest to meet their energy demand. A large number of households consume forest food as compared to timber and fuelwood due to the availability of the resources. The Municipality as a whole is undergoing rapid development expected to continue throughout years. These developments are stimulated by mining activities and influx of people in the area. All these factors threaten the existing natural resources especially forest areas and water. Areas of these resources are declining due to the current demand for housing, new mining sites and continuous establishment of informal settlements. Trees and forest within peri-urban and semi-rural areas are in poor conditions as compared to urban and suburban areas. Poor waste management and poverty are issues aggravating the situation especially in poor developing sites that have been studied. Most agricultural sites have been transformed into residential areas, and thus exacerbating problems of food insecurity in the whole country. Household size has major influence in fuelwood, timber and forest food production as an increase or decrease in the size will determine the amount of consumption, production or development. Value for forest, access to forest, level of interaction and restrictions regarding the use of forest are also significant aspects contributing to forest productivity and development as they show the relationship that exists between forest and households. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2007.

Page generated in 0.0428 seconds