Thesis (MBA)-- Stellenbosch University, 1973. / ENGLISH ABSTRACT: no abstract available / AFRIKAANSE OPSOMMING: geen opsomming

This study was conducted to measure the effects of thinning coppice on Emory oak (Quercus emoryi). Thinning treatments were applied to sprouts of different ages. Height and diameter measurements were taken immediately after thinning and again one year later. Sprouts were classified into 5 age groups, 4 stump diameter groups, and 4 residual sprout groups. The interactions of these treatments and their effect on volume growth were analyzed. The results showed volume growth per stump was directly related to the number of sprouts per stump; volume growth per sprout was inversely related to the number of sprouts per stump; volume growth per stump and per sprout were both significantly affected by the age of the sprout at the time of thinning; and that stump diameter size had no significant effect on volume growth.

Commensurate with the increase in the planting rate of broadleaf species is the need to investigate forest management that uses mixtures of species and ages. Reliable data for woodland of this type is exceedingly rare and the need to advise managers is immediate. Management and investment decisions can be examined with models of forest growth and economics. Part 1: Forest growth models. Many models have been reviewed and the most appropriate selected for further development. This thesis concentrates on the improvement of distance independent individual tree models. This is a modelling approach that is compatible with current knowledge and ideas in ecology. Several general improvements have been made. New growth equations have been produced and then calibrated to diameter increment data. Estimates for height prediction have been derived from analysis of a large survey of trees. Competition has been represented by a new multiplier, with a consequent improvement in the predicted diameter frequency distributions. The prediction of biomass for a given quality of site was modified such that control is mediated by measures of density dependence and biomass increment, via mortality. Finally, the results from improved versions of the model were tested against the known change in diameter frequency distribution for Meathop Wood in Cumbria. The result showed a promising similarity, and the minor disparities appear to be linked to the modelling of regeneration. Part 2: A forest economics model. A new model to assess the relative profitability of a wide variety of management options has been devised. The model is easy to operate and allows comparison for many differing financial circumstances. It has been used for investigating the importance of major financial variables in the selection of forestry investments. Research into changing fiscal incentives, 'natural' management, and ideal planting densities for oak have also been completed by use of the model.

Doctoral thesis submitted in fulfilment of the requirements for the Degree of Doctor of Philosophy to the Department of Development Studies, Faculty of Humanities at the University of the Witwatersrand, Johannesburg, South Africa, 2016. / Abstract This study examines the dynamics of power and the significance of local environmental knowledge in natural resource management in Zimbabwe’s communal areas. It uses a case study of Bulilima District, broken down into into 3 components (Wards) for manageability of the study, to analyse the power configurations and the role played by local environmental knowledge in influencing decision-making processes among actors in the district with regard to mopane worms (Imbrasis beilina is the scientific name while icimbi is the vernacular name) and mopane woodlands (Colophospermum mopane is the scientific name while iphane is the vernacular name). It examines the significance of local environmental knowledge, i.e. indigenous knowledge and knowledge that developed as a result of a combination of knowledges from different ethnic groups and modern science. The study further examines the dynamics of the gendered nature of mopane worms and woodlands tenure regimes by putting under the spotlight the spaces and places where men and women interact, use and exert control over mopane worms and woodlands. It places history at the centre of our understanding of contemporary power dynamics and helps us to appreciate the importance of how local environmental knowledge has changed over time. To this end, the study argues that some of the contemporary conflicts over resources have their roots in the colonial era when the colonial government appropriated land from the locals and introduced discourses and practices such as conservation. Furthermore, it argues and demonstrates that the state is a critical player in determining access, use and control of natural resources. Based on rich ethnographic data collected by means of critical observations, in-depth interviews, narratives, and archival data, as well as aided by a brief survey, the study concluded that natural resource governance is a complex phenomenon in developing states. Power and knowledge play significant roles in influencing access, use and control of mopane worms and woodlands. Furthermore, while some locals still possess indigenous knowledge, practices and belief systems related to natural resource management, these are now less significant in influencing decisions on natural resource management. Indeed, the interplay of knowledge and power in resource management sees scientific culture and outside knowledge taking precedence over local forms of knowledge in the management of natural resources in the district. Key words: power, local environmental knowledge, indigenous knowledge, ZANU PF, natural resource management, access, mopane worms and woodlands, Bulilima, Zimbabwe / GR2017

Orientador: Mauro Galetti Rodrigues / Banca: Pedro Henrique Santin Brancalion / Banca: Marco Aurélio Ribeiro de Mello / Banca: Mathias Mistretta Pires / Banca: Carine Emer / Resumo: A extinção de animais é uma ameaça silenciosa nas florestas tropicais. As florestas tropicais estão se tornando ecossistemas defaunados, especialmente de animais de grande porte. No entanto, a defaunação vai além da perda de animais carismáticos, o que estamos perdendo são interações fundamentais que modulam a funcionalidade da floresta e, portanto, dos serviços ecossistêmicos associados. A defaunação tem efeitos sobre a dispersão de sementes, a ciclagem de nutrientes, a qualidade da água, a manipulação de matéria fecal, entre outros serviços ecossistêmicos. Nesta tese, exploramos os efeitos da defaunação de grandes animais no serviço ecosistêmico de estoque de carbono em florestas tropicais. Nós encontramos que o serviço ecossistêmico de armazenamento de carbono está sustentado pelos animais de grande porte, isso porque frugívoros grandes são os principais dispersores de árvores com sementes grandes e, as árvores com sementes grandes tendem a ser altas e com madeira densa, armazenando assim grandes quantidades de carbono. Portanto, a remoção de árvores de sementes grandes das florestas, devido à perda de dispersão induzida pela falta dos grandes frugívoros, pode reduzir o potencial do estoque de carbono da floresta. No entanto, a redução não é direta porque os frugívoros menores podem compensar parcialmente a perda dos grandes frugívoros. Além disso, a perda de grandes predadores de sementes também pode afetar o potencial estoque de carbono. Em comunidades fortemente defauna... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Animal loss is a silent threat of forest ecosystem. Tropical forests are becoming defaunated ecosystems, especially defaunated of large animals. The loss of animals goes beyond than the loss of charismatic animals, what we are losing are key interactions that modulate the functionality of the forest and therefore of the associated ecosystem services. For instance, defaunation have effects over seed dispersal, nutrient cycling, water quality and dung removal among others ecosystem services. In this thesis, we explore the potential effects of defaunation of large animals in carbon stock ecosystem services of tropical forest. We found that the carbon stock ecosystem service is supported by large animals due to large frugivores are the main dispersers of large-seeded trees and, large-seeded trees tend to be tall trees with dense wood, therefore, store high quantities of carbon. Hence, the removal of large-seeded trees from the forest, because of diminished dispersal induced by the lack of large frugivores, reduce the carbon stock potential of the forest. However, the reduction is not straightforward because smaller frugivores can partially compensate for the loss of large frugivores. Moreover, strong defaunation effects in the seed predators communities can also affect the carbon stock potential of the forest. In strongly defaunated communities small rodents tend to increase their abundance and the predation pressure over large seeds, reducing their recruitment. In addition, we e... (Complete abstract click electronic access below) / Resumen: La extinción de animales es una amenaza silenciosa en los bosques tropicales. Los bosques tropicales se están convirtiendo en ecosistemas defaunados, especialmente despoblados de grandes animales. Esta pérdida de animales va más allá de la pérdida de animales carismáticos, lo que estamos perdiendo son interacciones clave que modulan la funcionalidad del bosque y, por lo tanto, de los servicios ecosistémicos asociados. Por ejemplo, la defaunación tiene efectos sobre la dispersión de semillas, el ciclo de nutrientes, la calidad del agua, la eliminación de excrementos, entre otros servicios de los ecosistemas. A través de esta tesis, exploramos los efectos potenciales de la defaunación de animales grandes en el servicio ecosistémico de almacenamiento de carbono de los bosques tropicales. Encontramos que el almacenamiento de carbono es soportado por animales grandes debido a que los frugívoros grandes son los principales dispersores de árboles con semillas grandes y, los árboles con semillas grandes tienden a ser árboles altos con madera densa, y consequentemente, almacenan altas cantidades de carbono. En consecuencia, la eliminación de árboles de semilla grande del bosque, debido a la dispersión disminuida inducida por la falta de grandes frugívoros, puede reducir el potencial de reserva de carbono del bosque. Sin embargo, la reducción no es directa debido a que los frugívoros más pequeños pueden compensar parcialmente la pérdida de frugívoros grandes. Además, los fuertes efecto... (Resumen completo clicar acceso eletrônico abajo) / Doutor

Recent increase in forest mortality events worldwide and their relationship with drought episodes highlight the importance of understanding tree resilience to a changing climate. Empirical models of forest mortality have been typically used and were focusing on carbon related variables such as growth to predict tree death. Recent efforts have shifted toward a more mechanistic modeling of mortality. Mechanistic approaches use tree traits and climate as inputs to model processes and represent carbon and water fluxes, all necessary to plant life. The advantage of mechanistic approaches is their ability to account for potential adaptation of trees to climate change, but also to physically explore the causes of vulnerability and resilience to droughts. Mechanistically, the atmospheric demand for moisture at the canopy level is communicated to the tree through stomata, creating a water gradient between the leaves and the roots, and resulting in the ascent of sap via the plant hydraulic structure. Depending on the climate (temperature, atmospheric dryness, light, precipitation), different architectures will perform differently at maintaining the gradient. For example, deep roots can access deep water in dry regions and shallow roots can access rare precipitation events whereas larger leaf area increases the atmospheric demand for moisture. In very harsh conditions such as extreme or lasting droughts, the hydraulic structure might suffer from a steep water gradient. Protection against excessive gradients can be achieved either through an investment in a stronger structure (denser wood) or through a regulation of the pulling force at the top of the canopy (closing leaf stomata). Evolution of structures and physiological strategies have resulted in fitness advantages and partially explain the diversity of species architectures across climates. More importantly, this diversity is at the core of the vulnerability and resilience of each species to increased aridity and frequency of extreme events, and therefore its mortality. This dissertation investigates the resilience to droughts of two co-occuring species in common woodlands of New Mexico, USA. This location is of specific interest because drought conditions (high temperature and/or low precipitation) have become more frequent as a result of global warming and because these ecosystems have suffered extensive mortality in the last decades. The two species, Pinus edulis and Juniper monosperma have very different physiological strategies, which allows for an extra level of vulnerability comprehension. To further test their resilience to extreme drought and possibly future climatic conditions, I studied trees that were subject to a six-year rain-reduction experiment. In the first part we develop a mechanistic model of the tree functioning that includes water and carbon fluxes and is based on their respective supply-demand balances. We use this simplified mechanistic model to study the sensitivity of mortality to hydraulic structure variations and to the physiological strategy of each species. We find that for both species death resulted from an irreversible damage of tissues transporting water. Despite P. edulis’s ability to close stomata to reduce the atmospheric demand, they died first because of their vulnerable tissues. In the second part, I specifically investigate P. edulis’s structural response to drought at the canopy level. By dissecting branch anatomy at an annual resolution, I find that during droughts this species increase relatively more leaf area (water demand) compared to transport area (water supply). I suggest that the structural adjustments that occur at the branch level do not contribute to the protection of the tissues transporting water. In the third part, I analyze the anatomy of these tissues in branches of P. edulis. I find that in response to long-lasting drought the trees built tissues more efficient at transporting water but also more vulnerable to future drought. By contrast, a short-intense drought decreases efficiency without changing vulnerability. I hence show that during lasting drought the anatomical adjustment of branch tissues increase the vulnerability of the piñons. This study shows the importance of considering climate responses of structure and physiology together to compare resilience across species. It also shows that adjustments of hydraulic elements in response to drought tend to decrease hydraulic resilience and could favor a run-away scenario. If the population of Pinus edulis - a dominant species of the Southwest US - were to decline, major shift should be expected in related ecosystems.

Orientador: Sérgio Campos / Coorientador: Roberta Thays dos Santos Cury / Banca: Felipe Wanderley de Amorim / Banca: Renata Cristina Batista Fonseca / Resumo: A conversão de florestas naturais em pastagens, lavouras ou reflorestamentos homogêneos com espécies exóticas, pode influenciar processos ecológicos importantes alterando a dinâmica florestal. O trabalho teve como objetivo avaliar se reflorestamentos homogêneos de Pinus elliottii influenciam a remoção de sementes em uma vegetação secundária de Floresta Ombrófila Mista Montana adjacente. Assim, formulamos três hipóteses: (1) a remoção de sementes será maior na vegetação secundária de Floresta Ombrófila Mista Montana adjacente ao plantio de Pinus elliottii, em especial, onde as plantações se encontram em estágio inicial de desenvolvimento; (2) a remoção de sementes na vegetação secundária de Floresta Ombrófila Mista Montana será maior quanto mais distante da borda com plantio de Pinus elliottii; e (3) a remoção de sementes será diferente entre as espécies de Syagrus romanzoffiana, Araucaria angustifolia e Pinus elliottii. Foram selecionadas seis áreas de plantios de Pinus elliottii adjacentes a vegetação secundária de Floresta Ombrófila Mista Montana. Em cada área foram instalados cinco pontos amostrais, distribuídos ao longo de um transecto a uma distância de 0, 10, 25, 50 e 100 metros da borda florestal. Em cada ponto foram depositadas 13 sementes de cada espécie analisada. O monitoramento das sementes foi realizado após dois, sete, nove, 14 e 21 dias. No geral a taxa de remoção foi elevada para todas as espécies (100% para espécie Syagrus romanzoffiana, 98% para Pinus elliot... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Conversion of natural forests to pasture, crop or homogeneous reforestation with exotic species can influence important ecological processes by changing the forest dynamics. The objective of this work was to evaluate the effects of Pinus elliottii plantation on seed predation in a Mixed Ombrophilous Montane secondary forest. Thus, we formulate three hypotheses: (1) seed removal will be greater in the Mixed Ombrophilous Montane secondary forest adjacent to Pinus elliottii plantation, especially where the plantations are in early stages; (2) seed removal will be greater in the Mixed Ombrophilous Montane secondary forest farther from the forest edge; and, (3) seed removal will be different among Syagrus romanzoffiana, Araucaria angustifolia and Pinus elliottii species. Six Pinus elliottii areas adjacent to Mixed Ombrophylous Montane secondary forest were selected. In each area, five plots were distributed along 0, 10, 25, 50 and 100 meters from the forest edge. Were deposited 13 seeds by species in each plot. Seeds were monitored during two, seven, nine, 14 and 21 days. In general the removal rate was high for all species (100% for Syagrus romanzoffiana, 98% for Pinus elliottii and 49% for Araucaria angustifolia). Similarly, all distances from the forest edge showed high seed removal, however, Araucaria angustifolia showed reduced seed removal at the edge, with 33% of removal at 0 m against 70% at 100 m. These rates indicate the presence of forest-associated fauna, which may cause predation and/or secondary dispersal. The reduced seed removal of Araucaria angustifolia, a key species for Atlantic Forest, on the forest edge, may indicate losses in the wildlife associated with the forest edge adjacent to the homogeneous planting. In addition, the removal of Pinus elliottii seeds in the forest, if predated, may indicate a reduction of their invasive potential in natural areas. / Mestre

Contemporary scholarship of neoliberalism tends to emphasize its ubiquity, underscoring capitalism's permeation into life's most intimate spheres. However, I show through careful ethnographic description that even within the paradigmatically capitalist conditions of New Brunswick, Canada - popularly christened a 'company province' - marginalized communities continue to maintain anti-capitalist moralities. Based on eighteen months of participant observation, this ethnography examines how an Acadian forest community in northwestern New Brunswick cultivates an alternative regime of values and also how those values are contained, eroded, and politically disarmed. I explain how a moral system based in the division between insiders and outsiders emerged to ensure the survival of rural Acadian communities throughout longstanding historical conditions of material precarity. This moral dualism serves to maintain fierce egalitarianism between insiders while justifying underhanded and illegal techniques for appropriating resources from the outsider sphere. While the persistence of this communitarian, egalitarian, anti-materialist insider moral order and the sharing economy it sustains is notable, especially given prevalent scholarly assessments about neoliberalism's colonization of our very imaginations, I show that maintaining the insider moral order in the face of community members' increasing material engagements with capitalism produces compromises, contradictions, and violences. The Acadians' dualist moral system absorbs hierarchies such as race and gender in ways that ultimately violate insider aspirations to egalitarianism and obstruct the development of insider moral persistence into more politically transformative resistance. Preservation of the insider sphere also demands periodic renegotiation of its boundaries under the pressures of new forms of precarity, such that the cost of maintaining the insider community is the expulsion of some of its members. This dissertation is thus a study of how capitalism comes to accommodate dissident moralities in its midst in ways that defuse their political threat, and the mechanisms by which compliance with capitalism is coaxed and coerced even in contexts of ideological opposition.

This thesis deals with the proposal that environmentally benign items of free standing furniture may be produced by the use of such well established techniques as training and grafting natural tree growth to shape. The project has been driven by the growing environmental concerns of which mankind has become aware in the late twentieth century, and which are starting to exert such a powerful influence in the twenty first. A broad history of man's use and control of natural tree growth, ranging geographically from Europe to Australia, and in size from hand held agricultural picks to eighteenth century sailing ships, is followed by a brief description of the ways in which the explosive increase in world popuanon. together with the expanding industrial activities of the Western consumer society, are feared to be threatening the stability of the natural environment. The various disasters and catastrophic accidents which have brought this situation to the attention of the general public are briefly surveyed, together with National, International and a range of Industrial responses. As one of the professions most closely concerned with the production of consumer items, the various reactions of the Design Community are similarly examined. In conclusion, the author's proposal for an experimental item of furnitureenvironmentally benign in production, use and disposal - is described and illustrated. A simple free standing three legged stool, the form of both the item itself and that of the jig required to control it's growth, are described and illustrated. The growth of examples of this, carried out on three sites across southern Britain are documented, experimental results reported and discussed. A further range of designs suitable to be produced using this method of controlling and grafting natural growth is proposed, and suggestions made for further experimentation.

Graduation date: 1998