An experimental forest watershed, consisting of three small catchments at Berembun, Negeri Sembilan, in Peninsular Malaysia has been monitored from 1979 to 1987. Adequate instruments were installed for continuous collection of hydrologic and climatic data. The calibration and post-treatment phases lasted for three and four years respectively. Two types of treatments were imposed -namely commercial selective logging and supervised selective logging in catchment 1 and catchment 3 whilst catchment 2 remained as a control. Pertinent logging guidelines were prescribed and assessed in C3 in terms of hydrological responses. Significant water yield increases were observed after forest treatment in both catchments amounting to 165 mm (70%) and 87 mm (37%) respectively in the first year; increases persisted to the fourth year after treatment. Magnitude and rate of water yield increase primarily depended on the amount of forest removed and the prevailing rainfall regime and the increase was largely associated with baseflow augmentation. Interestingly, both types of selective loggings produced no significant effect on peak discharge while the commercial logging resulted in a significant increase in stormflow volume and initial discharge. Such responses can be explained by the extensive nature of selective logging which normally left a substantial area of forest intact and minimal disturbance to flow channels. Thus, conservation measures introduced in this study - the use of buffer strips, cross drains, an appropriate percentage for the forest road network,- were found to be effective and beneficial in ameliorating the hydrological impacts.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第18338号 / 農博第2063号 / 新制||農||1023(附属図書館) / 学位論文||H26||N4845(農学部図書室) / 31196 / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 大澤 晃, 教授 髙部 圭司, 教授 北山 兼弘 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

Les termites forment un groupe animal important en milieu tropical, où leur richesse spécifique est plus élevée que dans n’importe quel autre écosystème. Ils se nourrissent de matière organique végétale à différent état de décomposition, du bois dur à la matière organique minérale du le sol. Cette diversification du régime alimentaire ne se produit que chez les Termitidae, parfois appelés « termites supérieurs », alors que les autres familles se nourrissent exclusivement de bois ou d’herbe. Les termites humivores sont extrêmement abondants en Amérique du Sud et en Afrique tropicale, mais sont relativement peu étudiés par rapport aux termites xylophages. C’est particulièrement vrai pour le groupe Anoplotermes, qui représente le groupe de termites le moins bien connu. Ce travail vise à faire la lumière sur l’écologie et la diversité de ce groupe strictement humivore, et comprend les sections suivantes : (1) Des échantillonnages standardisés dans sept sites de Guyane Française ont révèle, avec quelques exceptions, que les termites xylophages sont relativement peu spécialisés à un site. Au contraire, les espèces du groupe Anoplotermes, ainsi que les termites humivores en général, sont spécialisés à un type de forêt. Cette spécialisation contribue plus que probablement à la diversification écologique, et donc, à une augmentation de la richesse spécifique des termites humivores. (2) En utilisant les ratios d’isotopiques δ13C et δ15N, nous avons aussi trouvé qu’il existe une spécialisation des espèces le long d’un gradient d’humification chez le groupe Anoplotermes, de l’interface entre le bois pourri et le sol au sol pauvre en matière organique. Donc, au moins deux facteurs favorisent la richesse spécifique du groupe Anoplotermes dans le sol, malgré le manque d’évidence pour une séparation spatiale et temporelle entre les espèces. Cette spécialisation spécifique réduit la compétition interspécifique aux espèces se nourrissant de matière organique au même état de décomposition. (3) Ce mécanisme n’est probablement pas restreint aux espèces du groupe Anoplotermes et le ratio isotopique δ15N varie considérablement entre les termites humivores de manière générale. Les termites humivores comptent des espèces avec des régimes alimentaires différents ne partageant pas toujours les mêmes niches écologiques. Cette diversification du régime alimentaire ne c’est pas produit de manière aléatoire durant l’évolution des termites et les espèces proches tendent à se nourrir du même substrat. (4) Au niveau intraspécifique, il semble que la compétition contraigne la dynamique des colonies. En effet, chez A. banksi, nous avons trouvé que les nids matures sont surdispersés. Les nouveaux nids se trouvent principalement à une certaine distance des nids établis, plus particulièrement dans les trous laissés par les nids morts. Si ce patron est le résultat d’une sélection des sites de nidification, ou plutôt d’une exclusion compétitive reste sujet à discussion, mais met néanmoins en évidence la présence de compétition chez les termites humivores du groupe Anoplotermes. (5) Au vu de la richesse spécifique locale du groupe Anoplotermes, le nombre d’espèces décrites reste remarquablement bas. Après inspection du matériel type, seuls 30 espèces du groupe se sont avérés valides en Amérique du Sud, alors que 80% des espèces que nous avons collectées sont nouvelles pour la science. Cette disproportion entre ce qui est connu et la diversité réelle du groupe, met en évidence le besoin de réaliser des études supplémentaires pour améliorer la connaissance de ce groupe peu connu, le groupe Anoplotermes.

EU Forest and Conservation NGOs activities in Ghana from the perspective of public relations has been investigated. The methodology involved mixed research methods (qualitative and quantitative). Under the qualitative research approach, primary data were collected through unstructured questionnaires from the wood base and non-wood base small-scale forest enterprises, interviews were solicited from key informants including private logging companies and finally, forest fringe communities were visited and interviewed. Under the quantitative research approach, secondary data were collected through content analysis of EU institutions organisational press release, and an in-depth interview was conducted among all investigated institutions, content analysis of media houses was also collected to understand the sources of their news articles. Finally, official bulletins, published thesis, books, research articles, and journals were also consulted and used as a secondary data source for this research study. The result emanated from the administered questionnaires, in-depth interviews and focused group discussions reveals that public relations strategies and tactics can be used as a tool to enhance conservation education, manage forest crisis, empower local involvement, support livelihood programs and finally help reveal inefficiencies and bureaucracies in the state forestry sector, thereby contributing to sustainable forest management.

No description available.

Interactions are important drivers of selection and community structure, which makes the study of multi-species interactions critical for understanding the ecology and evolution of organisms. This dissertation includes four data chapters that examine the biotic and abiotic mechanisms that shape multi-species interactions in both tropical and temperate ecosystems. The first three data chapters (Chapters 2–4) were completed within a Neotropical rainforest in Costa Rica and focus on one plant genus, Piper (Piperaceae). The final data chapter (Chapter 5) was conducted within a working landscape of soybean (Glycine max) fields in eastern Maryland, USA. In Chapter 2, I explore intra- and inter-specific dietary niche partitioning of Piper fruits among three frugivorous bats, illustrating the importance of fine-scale mechanisms that facilitate species coexistence and influence plant–animal interactions. In Chapter 3, I demonstrate how the chemical ecology of a Neotropical shrub, Piper sancti-felicis, shapes fruit interactions with antagonists (fruit fungi) and mutualists (frugivorous bats and birds), developing a foundation for understanding evolutionary ecology of plant chemical traits based on phytochemical investment patterns. In Chapter 4, I describe the direct and indirect impacts of elevated temperature and CO2 concentration on the plant traits and interactions in Piper generalense, improving our understanding of the effects of climate change on a Neotropical plant–herbivore system. In Chapter 5, I explore the biotic (herbivore-induced plant volatiles) and abiotic (fine-scale weather conditions) drivers affecting insectivorous bat foraging in soybean fields in eastern Maryland, providing a pathway to further investigate new strategies for integrated pest management. As a collective work, this dissertation disentangles the nuances of multi-species interactions, exploring foundational mechanisms underlying biodiversity maintenance as well as answering applied questions to address a changing climate and aid sustainable agriculture. / Doctor of Philosophy / Everything in nature is connected, so studying ecological interactions requires us to view them from many different angles. As with most relationships, ecological interactions are multi-faceted and context-dependent. In this dissertation, I describe both tropical and temperate systems, collecting a variety of measurements from plants, microbes, and animals to explore the complicated relationships that exist between them. In Chapter 2, I explore how three species of fruit-eating bats may divide the use of a shared food resource (tropical pepper fruits in the genus Piper) to maintain separate populations and how those foraging differences may affect Piper plant populations. In Chapter 3, I characterize a chemical compound found in the fruits of a Piper plant species and test the effect of that compound on fruit fungi and fruit-eating bats and birds, leading to a better understanding of the selective pressures affecting fruit chemistry. In Chapter 4, I describe the direct and indirect effects of climate change on a Piper plant in the first study to measure the responses of tropical understory plants to treatments that mimic climate change using active warming and CO2 supplementation. In Chapter 5, I explore the fine-scale drivers of bat activity in soybean fields, including how weather conditions and the specific compounds emitted by insect-damaged plants may affect bat activity. As a collective work, this dissertation describes the complex relationships among plants and their many interactors, exploring questions from biodiversity maintenance to integrated pest management strategies.

The use of spatial statistics to investigate ecological processes in plant communities is becoming increasingly widespread. In diverse communities such as tropical rainforests, analysis of spatial structure may help to unravel the various processes that act and interact to maintain high levels of diversity. In particular, a number of contrasting mechanisms have been suggested to explain species coexistence, and these differ greatly in their practical implications for the ecology and conservation of tropical forests. Traditional first-order measures of community structure have proved unable to distinguish these mechanisms in practice, but statistics that describe spatial structure may be able to do so. This is of great interest and relevance as spatially explicit data become available for a range of ecological communities and analysis methods for these data become more accessible. This thesis investigates the potential for inference about underlying ecological processes in plant communities using spatial statistics. Current methodologies for spatial analysis are reviewed and extended, and are used to characterise the spatial signals of the principal theorised mechanisms of coexistence. The sensitivity of a range of spatial statistics to these signals is assessed, and the strength of such signals in natural communities is investigated. The spatial signals of the processes considered here are found to be strong and robust to modelled stochastic variation. Several new and existing spatial statistics are found to be sensitive to these signals, and offer great promise for inference about underlying processes from empirical data. The relative strengths of particular processes are found to vary between natural communities, with any one theory being insufficient to explain observed patterns. This thesis extends both understanding of species coexistence in diverse plant communities and the methodology for assessing underlying process in particular cases. It demonstrates that the potential of spatial statistics in ecology is great and largely unexplored.

Made available in DSpace on 2015-03-26T13:50:00Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1588514 bytes, checksum: 9a0a5adcf52a9faa39fd56223c08051d (MD5) Previous issue date: 2009-02-16 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Studying and monitoring the vegetation - forest, savannah or other types - is important to understand the current climatic standard. Dynamical vegetation models (DVM) are useful tools in biome studies as they are based on physical principles as well as on initial and boundary conditions, therefore can obtain evidence of the influence of factors on the modeled environment, predict future vegetation behavior and, in association with other models, make predictions about vegetation future influence on climate or about the effect of climate change on vegetation. In particular, reflectance models are part of DVMs. Some studies have attempted to identify, canopy elements on the response of the vegetation cover albedo, the effect of obtaining the best parameters configuration. However, the reflectance study for electromagnetic spectrum narrower bands shows further features of the studied objects. Important features are estimated from the response of specific bands vegetation reflectance. Therefore, the objective of this thesis was to add three bands - red, near infrared and blue, corresponding to the bands 1, 2 and 3 of the sensor MODIS, onboard the TERRA and AQUA satellites, into the IBIS model - Integrated Biosphere Simulator, observe the canopy reflectance sensitivity to architectural and optical parameters, and calibrate these parameters according to the surface reflectance products and vegetation index from MODIS for the Reserve Cuieiras (K34). The sensitivity analysis indicates a strong response to the upper canopy parameters. The parameters combination that minimizes the RMSE of EVI - Enhanced Vegetation Index (RMSE = 0.0245) are the slope of the upper canopy leaves up χ = 0.92, reflectance from the upper canopy leaves in the blue band blue−up ρ = 0.0162, red band red −up ρ = 0.0466 and near infrared band nir−up ρ = 0.4427. / Estudar e monitorar a vegetação - floresta, cerrado ou outro tipo de cobertura - é de suma importância para se entender o padrão climático atual. Os Modelos de Dinâmica de Vegetação (MDV) são ferramentas úteis nos estudos de determinado bioma, pois são baseados em princípios físicos e em condições iniciais e de contorno, podendo então obter indícios dos fatores que influenciam o ambiente modelado, fazer previsões futuras do comportamento da vegetação e, associados a outros modelos, fazer previsões futuras da influência da vegetação no clima, ou da mudança do clima na vegetação. Em particular, os modelos de refletância fazem parte dos MDV. Alguns estudos têm sido feitos para identificar a influência dos componentes do dossel sobre a resposta do albedo da cobertura vegetal, obtendo a melhor configuração dos parâmetros a serem usados. Porém, o estudo da refletância para menores faixas do espectro eletromagnético indica mais detalhadamente as feições dos alvos estudados. Para a vegetação, importantes características são estimadas a partir da resposta da refletância de faixas específicas. Nesse aspecto o objetivo desse trabalho foi adicionar três bandas vermelho, infravermelho próximo e azul, referentes às bandas 1, 2 e 3 do sensor MODIS, a bordo dos satélites TERRA e AQUA, no modelo IBIS - Integrated Biosphere Simulator - observando a sensibilidade aos parâmetros óticos e arquitetônicos do dossel e calibrando esses parâmetros de acordo com os produtos de refletância de superfície e índice de vegetação do MODIS para a Reserva do Cuieiras (K34). A análise de sensibilidade indicou forte resposta para os parâmetros referentes à parte superior do dossel. A combinação dos parâmetros que minimizou o RMSE do EVI - Enhanced Vegetation Index (RMSEmin = 0,0245) foi a inclinação das folhas do dossel superior up χ = 0,92, refletância das folhas da parte superior do dossel na faixa do azul blue−up ρ = 0,0162, vermelho red −up ρ =0,0466 e infravermelho próximo nir−up ρ = 0,4427.

京都大学 / 0048 / 新制・課程博士 / 博士(人間・環境学) / 甲第21848号 / 人博第877号 / 新制||人||210(附属図書館) / 2018||人博||877(吉田南総合図書館) / 京都大学大学院人間・環境学研究科相関環境学専攻 / (主査)教授 市岡 孝朗, 教授 加藤 眞, 教授 瀬戸口 浩彰, 准教授 西川 完途 / 学位規則第4条第1項該当 / Doctor of Human and Environmental Studies / Kyoto University / DGAM

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21971号 / 農博第2361号 / 新制||農||1071(附属図書館) / 学位論文||R1||N5222(農学部図書室) / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 大澤 晃, 教授 髙部 圭司, 教授 小杉 緑子 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM