Miombo is dry deciduous woodland dominated by leguminous tree species, covering a significant area of Africa south of the equator, including large parts of Angola, Malawi, Mozambique, Tanzania, Zaire, Zambia and Zimbabwe. This woodland type reaches its driest, most species-poor limit in Zimbabwe. Brachystegia spiciformis and Julbernardia globiflora are the two main dominants of the drier form of miombo. Miombo woodland represents a rich and diverse resource base for small-scale farmers throughout the region, the importance of which has been ignored in the past by managers and policy-makers. The development of sustainable management strategies for this resource has therefore been hampered by a lack of knowledge. For this reason, the overall objective of this research was to define the basis for sustainable management of these woodlands, firstly by developing techniques for measuring biomass and monitoring woody growth; secondly, by examining the effect of site conditions on productivity; and thirdly, by investigating biological and social aspects of the management of these woodlands. This research has found that good estimations of standing wood biomass of these two species can be derived from diameter and stem length measurements, thus providing woodland managers with a means of assessing the standing stock. The finding that B. spiciformis forms annual rings can be used in ageing the trees, projecting future yields more accurately, as well as monitoring the effects of management on growth. In the investigation of the effects of climatic and edaphic conditions on tree growth, soil depth was found to have the greatest influence, followed by mean annual rainfall and clay content. Dominant height was found to be the best morphological variable to estimate site potential, in the absence of detailed studies of soil characteristics. The experimental findings from silvicultural trials have important implications for management. Regrowth from coppice stools was vigorous even in dry years, and greatest from medium to large stools. Productivity in general was extremely variable, both of coppiced and uncoppiced trees, due to site effects. The most productive sites are also potentially the best for agriculture and are therefore unlikely to be left exclusively for woodland management. The silvicultural techniques of coppice reduction and water harvesting were not found to enhance coppice regrowth. Browsing by livestock was found to severely reduce coppice regrowth, particularly of J. globiflora, at least in the initial stages, so that protection from browsing in the first year or two after felling is recommended if maximum regrowth is desired. An assessment of the use and management of the indigenous wood resources in a resettlement area in central Zimbabwe suggests that the present harvesting of wood products is unsustainable, due largely to the lack of any woodland management policy for these areas. Local villagers feel powerless to exclude outsiders from their resource, and thus the incentives to manage it sustainably are low. Major changes in government legislation are necessary to alter this situation. In the interim, resource-sharing schemes are suggested as a method of improving the sustainability of use. Some of the results reported here have a direct application in miombo management; these are summarised at the end of this work in the form of guidelines for management. Others identify the need for further work to expand these initial findings. One of the outcomes of this research has been the reminder of how little is known of the appropriate management of this important vegetation type.

The interrelationships between species composition, resource-use and availability, breeding and competition were studied in two hill habitat raptor communities in a conserved reserve and an unprotected communal land in Zimbabwe in 1995 and 1996. The conserved Lonestar Study Area (LSA) and the unprotected Communal Land Study area (CLSA) had 38 and 31 raptor species, high and normal diversities for the area sizes respectively. An estimated 147 pairs of 21 raptor species bred in 40km² in the LSA compared to only 26 pairs of 22 raptor species per 40km² in the CLSA. Six species (African Hawk Eagle Hieraaetus spilogaster, Black Eagle Aquila verreauxii, Crowned Eagle Stephanoaetus coronatus, Little Banded Goshawk Accipiter badius, Barn Owl Tyto alba,and Barred Owl Glancidium capense made up 69% of breeding raptors in the LSA, while African Hawk Eagles, Little Banded Goshawks, Barn Owls and Barred Owls made up 58% of the breeding raptors in the CLSA. The abundance of Black, Crowned and African Hawk Eagles in the LSA was linked to abundant hyrax, Heterohyrax brucei and Procavia capensis and juvenile bushbuck Tragelaphus prey, and the high reproduction rates of Natal Francolin Francolinus natalensis (0.7 per ha when not breeding). Little Banded Goshawk and Barn Owl abundances were linked to their ability to change prey preferences according to prey availability. A fairly high rate of breeding attempts by eagles in the LSA in both years (60 - 76% of all pairs per year)was probably also linked to prey abundance, Most breeding failures were predator related, and were more common in areas of relatively low nesting densities indicating lower parental vigilance there. High eagle breeding densities were associated with small mean territory sizes in the LSA (7.7 - 10.7km² for the main eagle species). Eagles in the LSA usually nested closer to another eagle species than a conspecific, resulting in regular distributions of nests and no territory overlap within species. Differences in daily flight activity of eagles in both study areas, and in the onset of breeding between LSA eagles probably reduced interspecific aggression. Interspecific competition food and nest sites amongst LSA eagles was possibly lessened by slight ditferences in resource selection. Raptor resources were mostly unaffected by human activities in either study area during the study period. Differences in the raptor communities were probably as a result of natural habitat differences. The CLSA raptors potentially face resource loss through forest clearing and hunting. An expansion of the present CAMPFIRE program will protect the CLSA raptors.

The majority of the vegetation types occurring on Malilangwe Estate, in the south-eastern lowveld of Zimbabwe, are dominated by Colophospermum mopane (mopane). Over the past 30-50 years the stand density of these mopane vegetation types has increased, and an investigation was undertaken to determine the effect of season of burning and type of fire on mopane woodlands. From this study the following was ascertained: 1) A single predictive equation cannot be used over all seasons to estimate standing crop (fuel load) using the standard disc pasture meter procedure. The calibration equations developed using this procedure accounted for between 39 and 72% of the variation in standing crop, illustrating the high variation in basal cover of the grass sward, as well as the variation between months. Although the revised procedure, developed for areas with low basal cover, accounts for a lot more of the variation in standing crop, this procedure was not used to estimate standing crop over the study period because the calibration equation covered a number of vegetation types, and was not specific to the mopane woodlands. 2) Standing crop tracks effective rainfall (monthly rainfall divided by monthly pan evaporation) closely, with a lag period of less than one month. Standing crop can be estimated using a predictive equation that utilizes effective rainfall from the previous month. There is a positive relationship between peak standing crop and rainfall. A predictive equation was developed to estimate peak standing crop, using annual rainfall. Standing crop declines through the dry season as effective rainfall decreases, and this 'decrease function' allows for the estimation of the standing crop for a particular month, after peak standing crop is reached. 3) Two leaf quantification equations were developed for mopane trees in the south-eastern lowveld of Zimbabwe, one for coppicing and for non-coppicing individuals. These allow for the estimation of leaf dry mass from measured canopy volume. 4) There was no significant difference between the fire intensities attained for the three seasons of burning. Over all seasons, head fires were significantly more intense than back fires. 5) Percentage topkill after late dry season burns was significantly higher than topkill after early dry season burns. There was no significant difference between mid and late dry season burns, and head fires led to significantly more topkill than back fires. Plants < 150 cm experienced significantly more topkill (80 %) than did individuals > 150 cm (44%). 6) Fire per se led to an increase in stand density over all seasons and types of fire, but this change was not significant. Fire did not influence the nett recruitment of new individuals. Height class one (0-50 cm) and three (151-350 cm) were impacted most by fire. This reflects a change in tree structure, with an increase in the amount of leaf material in height class three, and a subsequent decrease in the amount of material in height class one. 7) The effect of season of burning on the change in tree height was significant, whereas the effect of type of fire was not significant. All treatments, except early dry season back fires, led to a reduction in tree height, whereas trees in the no burn areas increased in height. 8) Burning in any season, and implementing either type of fire, led to an increase in the number of stems. Mid dry season burns led to the highest increase in number of stems. However, the more intense the fire the smaller the increase in number of stems. 9) All three seasons of burning (head and back fires) led to a significant decrease in maximum canopy diameter per tree, while the maximum canopy diameter of trees in the no burn areas increased. Mid dry season burns resulted in the greatest decrease in canopy diameter. 10) The effect of burning on the change in leaf dry mass per tree was highly significant. All three seasons of burning led to a decrease in leaf dry mass, while there was no difference between head and back fires. Leaf dry mass in the control areas increased however. High fire intensities led to the greatest decrease in leaf dry mass, late dry season head fires having the greatest decrease. This study suggests that mopane plants face a constraint due to fire and/or browsing, and a tradeoff occurs between canopy volume, canopy diameter, canopy area; and number of stems. Fire leads to an increase in the number of stems through coppicing, while canopy volume and leaf dry mass decreases. This decrease is either (i) a tradeoff in response to increasing stem number, or (ii) a reduction in canopy because additional leaves on the new stems contribute to photosynthesis. The most important response to season of burning is the altered phenophase (phenological stage) of the plant. Early dry season burns cause the trees to be leafless during the early dry season (when unburnt trees are carrying full leaf), and then to be in leaf at the end of the dry season (when unburnt trees are leafless). It would appear that fire disturbance initiates leaf senescence after burning, and then leaf expansion earlier than normal i.e the whole leaf senescence/growth process is brought forward. Trees in late dry season burn areas remain leafless at the start of the rains, while trees in unburnt areas are carrying leaf. Being leafless these trees do not photosynthesize during this time, and it is proposed that the grass sward is advantaged by the reduced competition from the tree component. The consequences of these two changes in phenophase could not be addressed in this study, but are pertinent questions that must be answered if mopane woodland dynamics are to be more fully understood. Management recommendations for (1) the removal of unacceptable moribund grass material, or (2) the reduction of encroachment by woody species on Malilangwe Estate are also given. In an attempt to combat the increase in stand density of mopane it is recommended that high intensity head fires be implemented, when standing crop (fuel load) is sufficient and climatic conditions are conducive to maintaining high intensity fires. These should be carried out at the end of the dry season, before the onset of the rains. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2000.

Prepared by the Arid Lands Information Center, Office of Arid Lands Studies, University of Arizona ; Mark W. Speece, compiler.

No description available.

Thesis (MFor)--University of Stellenbosch, 2003. / ENGLISH ABSTRACT: The factors determining habitat selection of large herbivores, on a private wildlife reserve in semi-arid southeastern Zimbabwe, were investigated. Gross vegetative structure, herbaceous composition and topographic features thought to determine herbivore distribution were measured. Seasonal variation in resource distribution was considered, and research therefore extended over an entire year. Herbivore distribution and ecological niche separation was explained through several important environmental variables, and potential for inter-specific competition inferred. Additionally, predictive habitat suitability models were designed for each of the grazing species in the critical dry season. Herbivores showed a large degree of niche overlap in both the hotwet season and the cool-dry season, when food resources were more plentiful. Niche separation between grazers was pronounced in the hot-dry season. Herbivore distribution was associated most closely with distance to water, grass sward height, time since burn, woody plant density and by the presence of predominant grasses, these being Urochloa mossambicensis, Panicum maximum, Heteropogon contortus and Digitaria eriantha. Ecological separation of herbivores by the grasses P. maximum, H. contortus and D. eriantha was more indicative of associated environmental variables than feeding niche separation. A GIS-based analysis, using species presence data and quantitative coverages of environmental variables, produced maps of gradations of habitat suitability for grazing species during the dry season. Results of both analyses were integrated and gave a better understanding of ecological separation, and possible competitive interactions, among the large herbivore community on Malilangwe Estate. Recommendations were made based on the interpretation of findings, within the context of available management options. / AFRIKAANSE OPSOMMING: Die bepalende faktore van habitat seleksie by groot herbivore op ‘n privaat wildreservaat in semi-dorre suidoos Zimbabwe is ondersoek. Globale plantegroei stuktuur, kruidagtige samestelling en topografiese eienskappe wat glo herbivoor verspreiding bepaal, is gemeet. Seisoenale variasie in hulpbronverspreiding is in ag geneem en dus het navorsing oor ‘n hele jaar gestrek. Herbivoor verspreiding en ekologiese nisskeiding is verduidelik deur verskeie belangrike omgewingsveranderlikes en die potensiaal vir interspesifieke kompetisie is afgelei. Boonop is voorspellende habitat-geskiktheidsmodelle ontwerp vir elk van die weidingspesies in die krities droë seisoen. Herbivore toon ‘n hoë graad van nis oorvleueling in sowel die warm, nat seisoen as die koel, droë seisoen wanneer voedingsbronne meer volop is. Nis verdeling tussen weidiere was duidelik herkenbaar in die warm, droë seisoen. Herbivoor verspreiding is meestal geassosieer met die afstand na die water, die grasveld hoogte, tydperk sedert ‘n brand, digtheid van houtagtige plantsoorte en met die teenwoordigheid van die oorheersende grasse, Urochloa mossambicensis, Panicum maximum, Heteropogon contortus en Digitaria eriantha. Die ekologiese skeiding van herbivore deur die grasse P. maximum, H. contortus en D. eriantha het meer gedui op geassosieerde omgewingsveranderlikes as op skeiding van voedingsnisse. ‘n GIS-gebaseerde analise wat spesie-teenwoordigheidsdata en kwantitatiewe dekking van omgewingsveranderlikes gebruik, het klassifikasiekaarte geproduseer van habitatgeskiktheid vir weidiere tydens die droë seisoen. Resultate van beide analises is geïntegreer en het ‘n beter begrip van ekologiese skeiding en moontlike kompeterende interaksies tussen die groot herbivore gemeenskap op Malilangwe Estate tot gevolg gehad. Aanbevelings is gemaak, gebaseer op die interpretasie van bevindinge, binne die konteks van beskikbare bestuursopsies.

Discourse characterising climate change has largely revolved around aspects within the realm of impact identification, mitigation and adaptation. Apparently, a burgeoning appetite to examine the role of indigenous knowledge (IK) now confronts the fronts of climate science, policy and practice. The surge in attention to localbased knowledge is attributed to growing challenges posed by change and variability in the climate system. This study argues that indigenous-based knowledge is capable of filling knowledge gaps and validating current understanding about climate change particularly at local levels. Essentially, the paucity of knowledge about local climatic events can be circumvented by engaging indigenous ‘scientists’ whose many years of direct contact with the environment have equipped them with the indispensable knowledge, skills and experiences to understand the same. Primarily, the thesis’ objectives were threefold. One, it captured useful indicators of climate change and variability from the understanding of the indigenous people, which can also be used to enhance understanding of climate change impacts.Two, it drew from the knowledge, experiences, skills and practices of the locals in order to inform appropriate community level mitigation and adaptation interventions. And, three, it highlighted the fact that knowledge of the indigenous people can be used to direct research on climate change. The study area (Muzarabani in Zimbabwe) experiences recurrent droughts and floods and its villagers rely predominantly on climate-sensitive livelihoods. As such, it was selected to provide a reliable case on IK practices and experiences of the people witnessing climatic events. The study was framed within an epistemological and methodological configuration of emancipatory pedagogy that looks at the generators of climate knowledge as ‘scientists’ in their own right. A qualitative elicitation interviewing technique involving in-depth discussions with traditional leaders and elderly knowledgeable citizens was conducted. The participants were selected through chain referrals until the level of theoretical saturation. In addition, directed field observations, document analysis and key informant interviews with other respondents selected through theoretical sampling enhanced the robustness of data acquisition methods. Group-based participatory data analysis and reflexive pragmatism also enhanced rigour and quality of research findings intended to balance between the strictures of the scientific audience and the views of the knowledge generators. Three key themes were derived from IK-climate change linkages as: indigenous based indicators of climate change, indigenous-based mitigation and indigenous based adaptation. A range of indigenous-based indicators identified pointed to a progressively drier climate with shorter growing seasons that are also punctuated by mid-season dry spells. A trend towards increased desiccation of water bodies (rivers, ponds and vleis) was further observed. There is also an upsurge in the abundance and pestiferous nature of Macrotermes spp, Quelea quelea and Acanthoplus discoidalis, which are most likely related to climate change. Some of these indicators closely match with those used in mainstream climate science and they also serve to understand climate change impacts at a finer local level of analysis. Indigenous-based mitigation is mainly driven by the notion of sacredness where the locals regard forestry, certain trees and vleis as sacrosanct. Tampering with these is believed to upset the spirits who have powers to influence climate. Opportunities associated with IK deployment in climate mitigation are understood from the viewpoint of enhancing greenhouse gas (GHG) sinks and that of reducing vulnerability to extreme climatic events. Specifically, this can be achieved through enhancing GHG sequestration through forestry and land-use management initiatives; that is, reducing emissions from deforestation and forestry related degradation (REDD+) and Land Use and Land-Use Cover and Forestry (LULUCF). These two are the dominant schemes adopted by the Intergovernmental Panel on Climate Change (IPCC) to govern climate mitigation. Indigenous disaster risk management (DRM) strategies abound in drought, famine, flood and violent storms through various forms such as Zunde raMambo, nhimbe, rain-making ceremonies and community early warning systems (EWS).The locals in Muzarabani are not passive observers of the changing climate system. Increasing environmental risks necessitates them to devise countermeasures for responding to climatic stimuli with the intention of minimising harm and/or enhancing the benefits brought about by the same. Thus, a portfolio of IK-based adaptation strategies best described as an assortment of short-term coping practices and longterm adaptive strategies were identified. These range from exploitation of ecosystem services, agricultural based interventions, riverine farming, traditional phonological knowledge (TPK) to migration. Therefore, it was revealed that community-based adaptation (CBA) can adequately leverage on IK to improve adaptive capacity and build community resilience against climate change. Clearly, the complementary role of indigenous-based knowledge cannot be disputed, given the demonstrated range of applications from identifying several indicators of change and variability in the climate system, examination of climate change impacts, to identification and assessment of mitigation and adaptation options. The study advises that exogenous climate interventions need to be congruent with indigenous based strategies to avoid maladaptation. To the climate research community therefore, it should be realised that IK is useful both as leads and as baseline knowledge for future work on the impacts of climate change, and in the assessment of climate interventions. In this regard, the remaining challenge is to formulate a framework of constructive dialogue between indigenous scientists and conventional scientists so as to make sure that the mutual benefits of the two knowledge forms are adequately harnessed. Handled well, such collaborative effort would ensure enhanced climate change knowledge for successful mitigation and adaptation strategies. Handled poorly, there is a risk that the developmental needs of communities exposed to climatic events would not be addressed.

Wetlands are stocks of natural resources limited in supply, in the middle of unlimited human wants with multiple uses to society, presenting an economic problem in as far as their rational and sustainable use is concerned. To that end, conflicting recommendations have been forwarded regarding wetland cultivation as a possible land use across the globe and from within the same regions. On one extreme, wetland cultivation has been linked to degradation of wetlands with pure wetland conservation as the prescribed viable and sustainable land use option to society. Closer to reality, partial wetland conversion to crop land has been found compatible with wetland bio-diversity; implying that partial wetland cultivation is the prescribed wetland use option viable and sustainable to societies, a dictum mainly claimed by rural communities. With that conflicting background and based on the “Safe Minimum Standard” approach, a ban on wetland cultivation was maintained in several early environmental policies in Zimbabwe as a basis for legislative protection of wetlands, a position that is still legally binding in current statutes. Contrary to that, rural communities have responded by invading wetlands as a coping strategy in pursuit of the claimed values of wetland cultivation, further conflicting with standing policies. This scenario has managed to “lock” and is currently locking the claimed 1,28 million hectares of wetlands in Zimbabwe in a “legal-operational impasse”, at a cost to the entire nation since no meaningful investment is possible in wetlands when there is a legal conflict.

PhD (Geography) / Department of Geography and Geo-Information Sciences / Conservation agriculture (CA) which is an agricultural system with the capabilities of conserving soil and water through its zero to minimal tillage, mulching and crop rotation principles has become popular the world over. This study evaluated CA as an adaptation tool to drought in Chivi district, Zimbabwe. It developed a model to enhance adaptation to drought in Chivi and other areas of similar environment. The VLIR-UOUS (2019) Theory of Change (ToC) principles structured interview checklist was used to review the Logical Framework of CA to establish the project design. Questionnaires, key informant interviews and Focus Group Discussions were used to characterise the nature of CA in Chivi and to assess the socio-economic impact of the project. Official records were used to compare food crop production yields per hectare under conventional and conservation agriculture. Atlas.ti 8‘s capabilities such as Co oc for frequency of occurrence, Co-code Doc Table for numeric analysis, Networks and report tools for visual and text analysis were employed in data analysis. Statistical Package for Social Science (SPSS version 22) was used for its uni-variate and bivariate analysis capabilities. The findings highlighted weaknesses in the Chivi CA principles and project design. It noted a low adoption of the project with some farmers withdrawing from the project against a downward trend in food production, despite CA having higher yields per hectare. The study also noted low socio-economic impact of CA as a project and its potential outside the project framework. The study concludes that CA has can alleviate the drought effects if the project’s framework is adjusted to suit local context / NRF

Text in English / Ruti dam is located on the Nyazvidzi river, and is home to many Nile crocodiles (Crocodylus niloticus), which rely on fish and livestock for food. The community also relies on the dam and riverine for its resources. The investigation of crocodile impacts on humans and livestock, the trends and seasonality of attacks and identification of other predators resulted in formulation of research. The field interviews, using a structured questionnaire, field observation and focused group discussions were mainly used in data collection. Threats posed by crocodiles were identified as mainly human and livestock depredation, which has increased since the introduction of the crocodiles into the dam. The crocodile depredation varies between seasons, due to differences in water levels in the dam, and availability of alternative water sources. The attacks were mostly during the dry season and at the beginning of the wet season, when there were fewer water sources and when the water was dark and murky. The study assessed the human-crocodile conflict situation, based on interviews with the local residents and focused group discussions with fishermen. The conflict arose with livestock farmers after animal kills and fishermen, in cases of death, injury or damage to fishing gear. The killing of either humans or livestock was during the early hours of the day. Hostile attitudes of the residents towards crocodiles were high (83.9%). The majority, given the chance to eliminate the crocodile, would do so mercilessly. These negative attitudes can only be ameliorated when the damage is adequately compensated. The absence of compensation has increased the conflict, though no retaliation is taken against the crocodiles. The crocodiles prefer cattle in their kills (41% and 48%), followed by goats (38% and 25%), and, lastly, humans, in Buhera Rural District Council (BRDC) and Gutu Rural District Council (GRDC), respectively. Livestock farmers who stay close to the dam and Nyazvidzi suffer more losses, as their animals are more oftenly exposed to the dangers of crocodile predation, than those of farmers who stay far away, as they can use alternative water sources, and their animals are less likely to be exposed to the dangers of the crocodiles. The settlement pattern in BRDC has had an influence on predation. The farmers have also developed new livestock management techniques to reduce the loss of livestock. The fishermen suffer net damage on most occasions of their fish catches, as the crocodile might have learnt to follow the plastic floats on the water for easier prey from the nets. The fishing strategies have been developed to reduce fish loss. The death of fishermen is mostly that of people who enter the dam without canoes; no deaths were recorded of fishermen in canoes. Also, no capsizing of canoes has been recorded in Ruti dam, as fishermen always move in groups. Attacks in the Nyazvidzi River were on women and schoolchildren. Hyenas, as with the crocodile, have contributed to high kills of livestock (71.1%) and human kills were also reported in 2012 and July 2013. Though conflicts exist in the area, recommendations were made which might help to lower the conflicts. Educational campaigns and direct incentives from predator losses were identified as the main factors in conflict resolutions. The information on the importance of the predators and how or when it kills should be taught to respondents as they will be able to protect their livelihood. / Environmental Sciences / M. Sc. (Environmental Management)