• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 5
  • 2
  • 1
  • Tagged with
  • 9
  • 9
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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

Cobertura florestal vs. isolamento: efeito da paisagem sobre a provisão do serviço de polinização ao café. / Forest cover vs. forest isolation: the landscape effect on pollination service supply, demand and flow to coffee crop

Gonzalez Chaves, Adrian David 29 July 2016 (has links)
Na medida em que as demandas agrícolas continuam se expandido, aumenta a necessidade de que a produção agrícola garanta a conservação da diversidade e a provisão de serviços ecossistêmicos. O intuito do trabalho é avaliar independentemente o efeito da distancia aos fragmentos florestais e a cobertura florestal numa escala local. Quantificamos a diversidade de abelhas e a formação de frutos em 24 cultivos de café dentro de paisagens complexas de 2km de radio, compostas por mosaico de usos da terra, café, Mata Atlântica (20 - 27%) e outros usos. Adicionalmente estimamos a contribuição das espécies na formação de frutos depois de uma visita única, em cinco dos 24 pontos amostrais. No total foram identificadas 31 abelhas que visitam o café, a maioria abelhas sem ferrão (Meliponini) e abelhas da família Halictidae. No existiu diferencia na formação de frutos depois das visitas únicas das diversas especies de abelhas, o que sugere que há uma complementaridade na provisão do serviço. No entanto, a maior produtividade esteve associada à abundância de abelhas nativas. Em geral, 8% foi o incremento associado ao papel das abelhas o qual diminuiu com aumento da distancia para os fragmentos de mata assim como também conforme aumentava a quantidade de café na escala local (400 m de raio no entorno do ponto amostral). O efeito negativo da distancia aos fragmentos reforça a importância da vegetação natural em prover diversidade de abelhas e por tanto o serviço de polinização. O efeito negativo da cobertura de café sobre a frutificação sugere que há um excesso de demanda que excede a capacidade dos polinizadores de prover o serviço dentro de paisagens complexas. Nossos resultados mostram que a estrutura da paisagem afeta a densidade, riqueza e composição de espécies de polinizadores. Por tanto recomendamos como estratégia para incrementar a produção de café, sem necessidade de aumentar a cobertura florestal, manegar as áreas agrícolas para aumentar a dispersão entre fragmentos florestais e plantios de café, com o intuito de criar paisagens mais fragmentadas que facilitem o fluxo de polinizadores ao café / As the demands on agricultural lands continue to expand, effective strategies are urgently needed to manage agricultural production to guarantee biodiversity conservation and ecosystem service provision. Here we assessed independently the effect of forest isolation and local forest cover over bee diversity and on the provision of pollination service to coffee. We quantified bee diversity of flower visitors and fruit set in 24 coffee fields within three complex landscape of 2km radius surrounded by mosaic of coffee plantations, Atlantic forest fragments (20 - 27%), pastures and other lands uses. Additionally, we estimated species contribution to fruit set after single visit in five of the 24 coffee sites. In total we identified 31 bee species visiting coffee flowers, most being stingless bees (Meliponini tribe) and sweat bees (Halictidae). The absence of difference in fruit set after single visit by Apis and natives bee suggest that service complementation. Although, higher abundances of sweat bees and stingless bees were positively related to fruit set. Coffee fruit set was overall 8% higher in the presence of bees, and responded negatively to isolation from forest fragments and to high coffee cover at a local landscape scale (400 m radius landscape surrounding each sampled coffee bush). The negative association between isolation and fruit set reinforces the importance of natural vegetation to enhance bee diversity and therefore the provision of pollination service. The negative effect of coffee cover on fruit set suggests that the service demand can surpass pollinators\' capacity to provide service within complex landscape. Our results provide clear evidences that landscape structure can affect the abundance, richness and composition of pollinators\' species, and thus can indirectly regulate the provision of pollination service. Therefore we recommend, as a strategy to increase coffee yields without necessarily expanding forest cover, to manage agricultural landscapes in order to increase interspersion between forest fragments and coffee plantation thus a more patchy landscape mosaic that may facilitate pollinators flows to coffee crop
2

Cobertura florestal vs. isolamento: efeito da paisagem sobre a provisão do serviço de polinização ao café. / Forest cover vs. forest isolation: the landscape effect on pollination service supply, demand and flow to coffee crop

Adrian David Gonzalez Chaves 29 July 2016 (has links)
Na medida em que as demandas agrícolas continuam se expandido, aumenta a necessidade de que a produção agrícola garanta a conservação da diversidade e a provisão de serviços ecossistêmicos. O intuito do trabalho é avaliar independentemente o efeito da distancia aos fragmentos florestais e a cobertura florestal numa escala local. Quantificamos a diversidade de abelhas e a formação de frutos em 24 cultivos de café dentro de paisagens complexas de 2km de radio, compostas por mosaico de usos da terra, café, Mata Atlântica (20 - 27%) e outros usos. Adicionalmente estimamos a contribuição das espécies na formação de frutos depois de uma visita única, em cinco dos 24 pontos amostrais. No total foram identificadas 31 abelhas que visitam o café, a maioria abelhas sem ferrão (Meliponini) e abelhas da família Halictidae. No existiu diferencia na formação de frutos depois das visitas únicas das diversas especies de abelhas, o que sugere que há uma complementaridade na provisão do serviço. No entanto, a maior produtividade esteve associada à abundância de abelhas nativas. Em geral, 8% foi o incremento associado ao papel das abelhas o qual diminuiu com aumento da distancia para os fragmentos de mata assim como também conforme aumentava a quantidade de café na escala local (400 m de raio no entorno do ponto amostral). O efeito negativo da distancia aos fragmentos reforça a importância da vegetação natural em prover diversidade de abelhas e por tanto o serviço de polinização. O efeito negativo da cobertura de café sobre a frutificação sugere que há um excesso de demanda que excede a capacidade dos polinizadores de prover o serviço dentro de paisagens complexas. Nossos resultados mostram que a estrutura da paisagem afeta a densidade, riqueza e composição de espécies de polinizadores. Por tanto recomendamos como estratégia para incrementar a produção de café, sem necessidade de aumentar a cobertura florestal, manegar as áreas agrícolas para aumentar a dispersão entre fragmentos florestais e plantios de café, com o intuito de criar paisagens mais fragmentadas que facilitem o fluxo de polinizadores ao café / As the demands on agricultural lands continue to expand, effective strategies are urgently needed to manage agricultural production to guarantee biodiversity conservation and ecosystem service provision. Here we assessed independently the effect of forest isolation and local forest cover over bee diversity and on the provision of pollination service to coffee. We quantified bee diversity of flower visitors and fruit set in 24 coffee fields within three complex landscape of 2km radius surrounded by mosaic of coffee plantations, Atlantic forest fragments (20 - 27%), pastures and other lands uses. Additionally, we estimated species contribution to fruit set after single visit in five of the 24 coffee sites. In total we identified 31 bee species visiting coffee flowers, most being stingless bees (Meliponini tribe) and sweat bees (Halictidae). The absence of difference in fruit set after single visit by Apis and natives bee suggest that service complementation. Although, higher abundances of sweat bees and stingless bees were positively related to fruit set. Coffee fruit set was overall 8% higher in the presence of bees, and responded negatively to isolation from forest fragments and to high coffee cover at a local landscape scale (400 m radius landscape surrounding each sampled coffee bush). The negative association between isolation and fruit set reinforces the importance of natural vegetation to enhance bee diversity and therefore the provision of pollination service. The negative effect of coffee cover on fruit set suggests that the service demand can surpass pollinators\' capacity to provide service within complex landscape. Our results provide clear evidences that landscape structure can affect the abundance, richness and composition of pollinators\' species, and thus can indirectly regulate the provision of pollination service. Therefore we recommend, as a strategy to increase coffee yields without necessarily expanding forest cover, to manage agricultural landscapes in order to increase interspersion between forest fragments and coffee plantation thus a more patchy landscape mosaic that may facilitate pollinators flows to coffee crop
3

Hétérogénéité des pratiques agricoles biologiques et conventionnelles dans les paysages bretons : effets sur les communautés d'insectes auxiliaires à différentes échelles / Heterogeneity of organic and conventional farming practices in agricultural landscapes in Brittany : effects on natural enemy communities at different scales

Puech, Camille 15 December 2014 (has links)
En réponse aux pertes de biodiversité et à une insécurité alimentaire croissante, l’agriculture moderne doit se tourner vers une gestion plus durable des paysages agricoles. L’Agriculture Biologique (AB) est considérée comme une solution prometteuse à ces enjeux. En effet, ses pratiques agricoles étant globalement plus favorables aux ennemis naturels de ravageurs que celles de l’Agriculture Conventionnelle (AC), elle pourrait permettre de remplacer l'utilisation des pesticides par celle du contrôle biologique. Cependant, les études évaluant ces effets restent contradictoires, probablement car elles ne tiennent pas compte de la diversité des pratiques réalisées en AB et en AC. A plus large échelle, les pratiques ont par ailleurs rarement été considérées dans la description de l’hétérogénéité paysagère, bien que la nature et l’organisation spatiale de la matrice agricole soit susceptible d’affecter les espèces qui y vivent. L’objectif de ce travail de thèse est d’évaluer les effets de la diversité et de l’organisation spatiale des pratiques en AB et en AC sur les insectes auxiliaires, à l’échelle de la parcelle et du paysage. Un travail de terrain a été réalisé en 2012 et 2013 en Ille et Vilaine. Quarante paires de parcelles de blé d’hiver en AB et en AC ont été sélectionnées, réparties le long d’un gradient paysager de surfaces en AB. Dans chaque parcelle, les communautés d'ennemis naturels de pucerons (coccinelles, carabes, parasitoïdes) ont été échantillonnées. Des enquêtes ont permis de caractériser les pratiques agricoles réalisées par les agriculteurs dans les parcelles suivies et dans leur environnement paysager. Nous avons mis en évidence l’existence d’une large diversité de pratiques agricoles dans les systèmes en AB et en AC. A l’échelle parcellaire, les effets des pratiques sur la diversité des insectes auxiliaires sont forts, les systèmes en AB leur étant globalement plus favorables. Considérer un niveau plus fin de description des pratiques nous a permis d’identifier celles qui affectent réellement les insectes et de montrer qu’il est possible de favoriser leur présence, quel que soit le mode de production. A l’échelle du paysage, nous n’avons mis en évidence aucun effet de l’étendue et de l’organisation de l’AB sur les ennemis naturels. Une description plus fine des pratiques nous a malgré tout permis de souligner l’importance de certaines stratégies de pratiques, à certaines échelles. A partir de ces résultats, nous proposons des pistes pour l’aménagement des paysages agricoles. Les problèmes méthodologiques liés à la description des pratiques agricoles à l’échelle du paysage sont également discutés. / Due to the loss of biodiversity and increasing food insecurity, modern agriculture must evolve toward a more sustainable management of agricultural landscapes. Organic Farming (OF) is considered as a promising solution to meet this challenge. Organic practices are indeed generally more favorable to pest natural enemies than Conventional Farming (CF), suggesting that pesticides could be replaced by biological control. However, studies evaluating these effects are contradictory, probably because they do not consider the diversity of practices implemented in OF and CF. On a broader scale, practices have rarely been considered in the description of landscape heterogeneity, although the nature and configuration of farmland must affect species. The target of this PhD work is to evaluate the effects of the diversity and spatial organization of organic and conventional farming practices on insect natural enemies, at field and landscape scales. A fieldwork was conducted in 2012 and 2013 in Brittany. Forty pairs of organic and conventional winter wheat fields were selected, distributed along a landscape gradient of OF area. In each field, aphid natural enemies (ladybirds, carabid beetles, parasitoids) were sampled. We interviewed farmers to characterize farming practices implemented in fields and their surrounding landscape. We observed a wide diversity of farming practices in OF and CF. At field scale, effects of practices on the diversity of natural enemies were strong, OF being overall more favorable. Considering a finer description of practices allowed us identifying those really affecting insects, and showing they can be enhanced regardless of the farming type. At landscape scale, we found no effect of the OF area and configuration on natural enemies. With a more detailed description of practices, we however highlighted the importance of some farming strategies, at some scales. Based on these results, we open up avenues to manage agricultural landscapes. Methodological issues related to the description of farming practices on large areas are also discussed.
4

Arthropod and plant diversity of maize agro-ecosystems in the grassland and savanna biomes of South Africa / Monique Botha

Botha, Monique January 2014 (has links)
Maize (Zea mays L.) is the most important grain crop in the country. Approximately 12 million tons of maize grain is produced annually on approximately 2.5 million ha of land. However, increased farming intensity can lead to fragmentation of habitat and has a tendency to decrease the biodiversity of an area. Therefore, to ensure the continued functionality of agro-ecosystems, methods in agriculture must be assessed and adapted when necessary to ensure the persistence of biological diversity. Unfortunately, the effect of crop production on species diversity and composition in South Africa is still relatively unknown, and no baseline data exists with which to gauge the possibility of unknown extinction risks of important biological elements. The objectives of this study were to compare plant and arthropod diversity patterns and species turnover of maize agro-ecosystems between biomes (grassland and savanna) and along a maize field-field margin gradient (MAFFMAG). Surveys of maize agro-ecosystems were conducted in six provinces of South Africa, namely North-West, Mpumalanga, KwaZulu-Natal, Limpopo, Free State and the Eastern Cape. Repeated measures ANOVA revealed a significantly lower plant and arthropod species diversity and richness in maize fields compared to field margins. Non-metric multidimensional scaling revealed that arthropod species composition differed between biomes although not along MAFFMAGs, indicating that arthropod species composition is dependent on biome rather than distance from maize field. Floristic data revealed unique species compositions for maize fields and field margins and also for biomes. Furthermore, maize fields and field margins of grassland sites were more similar in plant species composition than the savanna localities, suggesting higher regional beta diversity for savanna regions. Spearman‘s rank order correlations revealed generally positive but weak or no relationships between plant and arthropod diversity. This study provides baseline data for identification, monitoring and conservation of priority species and will allow the future evaluation of ecosystem services provided by plants and associated arthropods, especially natural enemies of pests, in maize agro-ecosystems. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2014
5

Interwoven tributaries : a community genetics platform for ecological interactions

Khudr, Mouhammad Shadi January 2012 (has links)
Community genetics research investigates the influence of intra-specific genetic variation on species interactions. This rapidly growing research field consists of more than one approach to explore how a significant portion of the environment of a focal species is differentially defined by the expressed genomes of other interacting species. While the basic concept of community genetics is well supported empirically, there is still a set of pertinent issues in need of further investigation. The initial research addressed herein focused on the extent to which the magnitude of a community genetic effect can be moderated when acting in concert with other forces in nature, i.e. the interaction between community genetic effects and the effects of other eco-evolutionary processes such as competition and parasitism. Subsequent research investigated the impact of genetic variation of host plants in agro-ecosystems on the performance (reproductive success) and behaviour (distribution and feeding-site choice) of plant-associated pests such as aphids, especially when pests and their hosts were subject to plant-mediated interactions. In addition, the differential effects of Indirect Ecological Effects (IEEs) and Indirect Genetic effects (IGEs) on the emergence of shared (extended) phenotypes between natural enemies (i.e. biological control agents and phytophagous insects) were examined. I provide clear evidence for significant effects of the genetic variation of host plant on aphid performance, behaviour and intra- and inter-specific competition. My findings also give credence to the concept of reciprocal moderation between plant genotype and aphid competition. I also provide observations on competition that segues into less antagonistic and possibly into a more cooperative form of interaction. In addition, I establish novel systems of economically important crop genotypes, noxious sap-feeding aphid species and root-galling nematodes. I also devise an amalgamated approach to interpret the interwoven set of mechanisms that underpin the observations presented and conclusions drawn. I also provide further investigation on the role of Indirect Ecological Effects (IEEs) between root-knot nematodes and sap-feeding aphids, and demonstrate the influence of in-plant variation on the interaction between the spatially separated plant consumers. Furthermore, I use a quantitative genetic experimental design in order to demonstrate a differential impact of parasitoid genotype on the behaviour of its aphid host. As such, I provide some of the clearest evidence to date that the phenotype of an organism can be the product of the genes expressed in another organism via Inter-specific Indirect Genetic Effects (IIGEs). Finally, I conducted research on epiphytic bromeliads and their associated faunal communities in the tropics. Here I demonstrate that the influence of intra-specific genetic variation of the host plant on the associated ecological communities may be more universal than previously conceived, with a plausible role for such variation in the maintenance of biological diversity. My research provides evidence for the genetic basis of species interactions and, interestingly, a genetic basis for the evolutionary arms-race between foragers and their hosts. My doctoral work adds new evidence to the increasing literature on the evolutionary importance of (Genotype x Genotype) interactions and (Genotype x Genotype x Environment) interactions in shaping the dynamics of pest communities, which in turn can affect plant phenotype and can influence the properties and services of the focal ecosystem in which the inter-players live and interact.
6

Arthropod and plant diversity of maize agro-ecosystems in the grassland and savanna biomes of South Africa / Monique Botha

Botha, Monique January 2014 (has links)
Maize (Zea mays L.) is the most important grain crop in the country. Approximately 12 million tons of maize grain is produced annually on approximately 2.5 million ha of land. However, increased farming intensity can lead to fragmentation of habitat and has a tendency to decrease the biodiversity of an area. Therefore, to ensure the continued functionality of agro-ecosystems, methods in agriculture must be assessed and adapted when necessary to ensure the persistence of biological diversity. Unfortunately, the effect of crop production on species diversity and composition in South Africa is still relatively unknown, and no baseline data exists with which to gauge the possibility of unknown extinction risks of important biological elements. The objectives of this study were to compare plant and arthropod diversity patterns and species turnover of maize agro-ecosystems between biomes (grassland and savanna) and along a maize field-field margin gradient (MAFFMAG). Surveys of maize agro-ecosystems were conducted in six provinces of South Africa, namely North-West, Mpumalanga, KwaZulu-Natal, Limpopo, Free State and the Eastern Cape. Repeated measures ANOVA revealed a significantly lower plant and arthropod species diversity and richness in maize fields compared to field margins. Non-metric multidimensional scaling revealed that arthropod species composition differed between biomes although not along MAFFMAGs, indicating that arthropod species composition is dependent on biome rather than distance from maize field. Floristic data revealed unique species compositions for maize fields and field margins and also for biomes. Furthermore, maize fields and field margins of grassland sites were more similar in plant species composition than the savanna localities, suggesting higher regional beta diversity for savanna regions. Spearman‘s rank order correlations revealed generally positive but weak or no relationships between plant and arthropod diversity. This study provides baseline data for identification, monitoring and conservation of priority species and will allow the future evaluation of ecosystem services provided by plants and associated arthropods, especially natural enemies of pests, in maize agro-ecosystems. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2014
7

How vertebrate communities affect quality and yield of macadamia farms in Levubu, South Africa

Linden, Valerie M. G. 15 May 2019 (has links)
PhD (Zoology) / Department of Zoology / Ecosystem services and disservices are important features in agro-ecosystems and both can have relevant economic impacts on farmers. While there has been much research on the value of ecosystem services, especially that of pest control by bats and birds, ecosystem disservices are often overlooked or estimated separately. Both, services and disservices, however, change with landscape and may be supported by natural vegetation. It is hence inevitable to assess them together to uncover their relative value and importance. Habitat loss and fragmentation are major threats to biodiversity and ecosystem services. Agricultural intensification can cause habitat loss and can negatively affect natural ecosystems and their services. However, the removal of natural vegetation can also reduce ecosystem disservices that origin from natural areas. This study focused on the economic trade-off between biocontrol by bats and birds and crop raiding by vervet monkeys in South African macadamia orchards, using vertebrate exclusion experiments. Crop quality and yield were assessed and extrapolated to income values. The study furthermore focused in more detail on the impact of orchard edge habitat and farm management on bats as ecosystem service providers as well as the arthropod community, which can provide both services (pollination, biocontrol) as well as disservices (crop damage). The macadamia industry is highly profitable and plantings are expanding worldwide. South Africa is currently the largest macadamia producer in the world and the study area, Levubu, holds some of the oldest macadamia plantings in the country. The subtropical climate and high annual rainfall make this area an intensively farmed landscape. Levubu lies at the foothills of the Soutpansberg, a centre of biodiversity and patches of natural vegetation wind through orchards of macadamia, avocado, banana and timber. Insect pest pressure is high in the macadamia industry, with several stink bug species (Hemiptera) and two moth species (Lepidoptera) accounting for most of the damage to the crop. Chapter One provides a detailed overlook over the South African macadamia industry, describes the major pest insect species and their impact on the crop and highlights the role of ecosystem services and disservices and the potential importance of remaining natural areas. Over three consecutive seasons, between September 2015 and May 2018, bats, birds and monkeys were excluded, using cages with nets, from a total of 96 macadamia trees. Four treatments were applied (Full, Day, Night, Control) to distinguish between effects of the different functional groups. Exclusions took place at orchard edges with natural or human-modified edge habitat to assess the impact of vicinity to natural vegetation on pest control and crop raiding. Results presented in Chapter Two showed that biocontrol by bats and birds was stronger near natural vegetation and significantly impacted crop quality as well as yield. Effects of bats and birds were still significant at human-modified edges, whereas crop raiding by monkeys is limited to the natural orchard edges. The economic impact analysis shows that the benefits of biocontrol through bats and birds outweighed the income losses due to crop-raiding monkeys. The value of bats and birds was as high as USD 5000 per hectare per year through prevented insect damage and a 60% crop increase. Crop-raiding affected the yield, which dropped by about 26% and resulted in losses of about USD 1500 per hectare. These results highlight the importance of integrating natural areas into agricultural landscapes, even if they incur the risk of being disadvantageous. Farmers need to be made aware of the enormous economic benefits. Effective crop raiding mitigation strategies still need to be researched to avoid negative association with natural areas. These can, however, possibly also limit access for biocntrol agents, like bats and birds and thereby reduce their economic impact. Especially the removal of natural areas or establishment of buffer zones of unpalatable crops between agricultural land and forests is not advisable. Integrative research in agro-ecosystems on trade-offs between a variety of ecosystem services and disservices is necessary in future, rather than assessing them separately. The bat community on macadamia farms was monitored monthly and compared between orchard edges. Stationary bat detectors were placed at each set of exclosures for two consecutive nights a month, automatically recording from sunset to sunrise. Recorded bat calls were identified manually to species level and activity converted to Miller’s activity index, which counts the number of active minutes per species per night. We analysed the activity per feeding guild over season and landscape setting, estimated species richness and diversity (Hill’s numbers) and species turnover between farms, season and landscape setting, using diversity partitioning. The bat community was mostly influenced by seasonality with season turn-over accounting for 21% of total bat diversity (21.25 species). Edge habitat on the other hand only accounted for 5%. We found higher species richness and activity in the high season compared to the low. While there was no difference in diversity in the high season between the two orchard edge types, species diversity at the human-modified edge was lower than in the natural during the low season. Natural habitat might therefore be more important in the low season, while its effect is overwritten by high food availability during the high season. Clutter-edge species furthermore were more active at the natural orchard edges than open-air feeders, which were in turn more active at human-modified edges. Both activities dropped significantly during the low season. Chapter Three concludes that the macadamia landscape is able to support a high bat species diversity, which is affected by seasonal differences, probably due to food availability. Natural areas are important to be maintained to support sensitive species, relying on clutter habitat and natural roosts. Habitat features as well as farm management can also influence arthropod communities. Visual observations took place each month for 20 minutes per tree. Observations were counted and identified to at least order level. Chapter Four concentrates on the impact of orchard edge habitat and insecticide treatment on honey bees (83% of Hymenoptera observations) abundance. Honey bees were the only taxon significantly responding to both variables, with higher abundance close to natural areas and increasing abundance with increasing time since pesticide application. Honey bees furthermore seemed to recover slightly quicker from population crashes after insecticide treatments at natural edges than they did at human-modified edges. Hymenoptera can be highly beneficial to macadamia farmers, as farmers are heavily relying on pollination by honey bees and parasitoids are known to feed on major macadamia pest insect species. These ecosystem service providers were mostly affected by habitat and management practices, which may compromise their ecosystem service provision. Although commercial bee hives are exposed throughout macadamia orchards, they do not appear to fully replace the pollination and biocontrol services provided by feral species, which can be enhanced through resource supplementation by patches of nearby natural vegetation. Chapter Five concludes with emphasizing the general importance of natural vegetation in landscape planning of agricultural areas. This study proved confidently that benefits through ecosystem services largely outweigh negative impacts of ecosystem disservices, both stemming from these natural areas. Through the inclusion, maintenance and restoration of such patches of natural vegetation, farmers can potentially increase the value and effectiveness of biocontrol by bats and birds or other services. Seasonality largely determined bat species diversity, and a general high species diversity was observed in the macadamia landscape, possibly due to a certain degree of landscape heterogeneity and high food availability. Activity patterns of clutter-edge and open-air feeding bats varied with edge habitat, while clutter-dependent bat species / NRF
8

Anthropocentric development evaluation : making people and their humanity the focus of development and its evaluation

Marais, Mark Trevor 01 1900 (has links)
The need for an Anthropocentric Development Evaluation stems from the inability of development theory and praxis, which has informed the past Development Decades, to ameliorate abject poverty experienced by most people throughout the world. Emanating from a hermeneutical-interpretist epistemology the fundamental argument of an Anthropocentric Development Evaluation is that people and the crucial aspects of their humanity should be the central focus in development and evaluation processes. Thus, taking the people-centred approach to development as its starting point, an Anthropocentric Development Evaluation draws attention to the marginalised, particularly the poor, the rural poor, resource-poor primary producers, women and their households. An Anthropocentric Development Evaluation also argues for an actor-orientation to Development Evaluation to emphasise the situational, yet individual behaviour, of people. Alongside such an approach, lies the significance of culture and people's knowledge for development, as well as the limitations, risks, uncertainties and vulnerabilities people face as a consequence of their humanity. These may influence the extent to which they participate in spontaneous or imposed development initiatives. An Anthropocentric Development Evaluation then comparatively assesses three sets of similar, yet different, methodologies using people and aspects of their humanity described above as the focus for that assessment. The methodologies assessed include Action Research, Social Impact Assessment and the Complementary Rural Development Field Tools. The purpose of doing so is to obtain a suitable medium through which to test the focus of an Anthropocentric Development Evaluation in a development setting. The testing of an Anthropocentric Development Evaluation in a development setting is done first by providing an Anthropocentric Development Evaluation of aspects of life of people living in the community of Nyanyadu in KwaZulu-Natal. Social Impact Assessments using the focus of an Anthropocentric Development Evaluation are then made of two development initiatives in respect of the people of Nyanyadu. These two initiatives are a nutrition and social development programme and the national land reforms. The purpose of all these evaluations is to examine the extent to which people and their humanity are seen to be crucial in development processes. / Development Administration / D.Litt. et Phil. (Development Administration)
9

Anthropocentric development evaluation : making people and their humanity the focus of development and its evaluation

Marais, Mark Trevor 01 1900 (has links)
The need for an Anthropocentric Development Evaluation stems from the inability of development theory and praxis, which has informed the past Development Decades, to ameliorate abject poverty experienced by most people throughout the world. Emanating from a hermeneutical-interpretist epistemology the fundamental argument of an Anthropocentric Development Evaluation is that people and the crucial aspects of their humanity should be the central focus in development and evaluation processes. Thus, taking the people-centred approach to development as its starting point, an Anthropocentric Development Evaluation draws attention to the marginalised, particularly the poor, the rural poor, resource-poor primary producers, women and their households. An Anthropocentric Development Evaluation also argues for an actor-orientation to Development Evaluation to emphasise the situational, yet individual behaviour, of people. Alongside such an approach, lies the significance of culture and people's knowledge for development, as well as the limitations, risks, uncertainties and vulnerabilities people face as a consequence of their humanity. These may influence the extent to which they participate in spontaneous or imposed development initiatives. An Anthropocentric Development Evaluation then comparatively assesses three sets of similar, yet different, methodologies using people and aspects of their humanity described above as the focus for that assessment. The methodologies assessed include Action Research, Social Impact Assessment and the Complementary Rural Development Field Tools. The purpose of doing so is to obtain a suitable medium through which to test the focus of an Anthropocentric Development Evaluation in a development setting. The testing of an Anthropocentric Development Evaluation in a development setting is done first by providing an Anthropocentric Development Evaluation of aspects of life of people living in the community of Nyanyadu in KwaZulu-Natal. Social Impact Assessments using the focus of an Anthropocentric Development Evaluation are then made of two development initiatives in respect of the people of Nyanyadu. These two initiatives are a nutrition and social development programme and the national land reforms. The purpose of all these evaluations is to examine the extent to which people and their humanity are seen to be crucial in development processes. / Development Administration / D.Litt. et Phil. (Development Administration)

Page generated in 0.0559 seconds