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  • 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.
31

A Study of the Cognition and Learning Motivation of Junior High School towards Biodiversity

Wang, Ghiu-huang 08 June 2009 (has links)
The biodiversity is the material base of human survival; however, the humanity is also destroying it with the astonishing speed. Therefore, examination of current students¡¦ cognition degree towards the biodiversity practically should be one of the foundation work before thoroughly promoting ecology preservation. This study aims first to find out the relationships of the middle-school students¡¦ understanding about the preservation of the biodiversity, their learning motivation, present situations as well as their background. In this study, the participatory objects are 1,312 junior high students from Taiwan. The data collected from them was analyzed by using the descriptive statistics, t-test, two-way ANOVA, one-way ANOVA, and Pearson¡¦s product-moment correlation. The results indicated that the average responding rate of middle-school students¡¦ knowledge towards the preservation of the biodiversity is 72.70%, and the percentage of their biodiversity learning motivation is 65.42, belonging to the moderate motive degree. The differences in sex, region of residence, year grade in school, social status of their mothers, inhabitant conditions have much to do with students¡¦ cognitions of the biodiversity preservation. And the region of residence, year grade in school, social status of their mothers, inhabitant conditions have much to do with students¡¦ learning motivation of the biodiversity. In addition, it reveals a remarkably positive correlation between students cognition of the biodiversity preservation and their learning motivation. Based on the above research discoveries, some recommendations for further research , the educate units and the teaching staff were suggested.
32

The effect of biodiversity on ecosystem functioning: The Patagonian steppe as a model.

Flombaum, Pedro. January 2008 (has links)
Thesis (Ph.D.)--Brown University, 2008. / Advisor: Osvaldo E. Sala. Includes bibliographical references (leaves 111-117).
33

Comparative thermal biology and associated niche differentiation among the five-lined skinks

Watson, Charles Matthew. January 2008 (has links)
Thesis (Ph.D.) -- University of Texas at Arlington, 2008.
34

Biodiversity in a rapidly changing world from local interactions to large scale patterns /

Baiser, Benjamin, January 2009 (has links)
Thesis (Ph. D.)--Rutgers University, 2009. / "Graduate Program in Ecology and Evolution." Includes bibliographical references.
35

Valuing rainforests : a botanical and ethnobotanical study of non-timber forest products in the Sinharaja forest of Sri Lanka

Batagoda, B. M. S. January 1997 (has links)
This study seeks to investigate whether the biodiversity conservation of the Sinharaja rainforest in Sri Lanka can be economically justified solely in terms of its non-timber forest products (NTFPs) extraction potential as claimed by some recent research. A variety of methods and techniques were deployed including a botanical inventory survey, a crosssectional ethnobotanical survey, an ethnobotanical log-book survey and an ethnozoological survey. Several aspects relating to the NTFPs use: a) valuing the total inventory stock, the total extractable stock limit, the potential flow and actual flow; b) estimating the wild meat flow; c) seasonality of harvesting; d) sustainability issues; e) influence of phytosociological characteristics; f) influence of socio-economic characteristics; and g) forest accessibility; and h) market accessibility were investigated. Biophysical and socio-economic factors influencing the NTFPs value were investigated using a regression analysis. The impact of the NTFPs extraction on the regeneration of the natural population was investigated using three forest sites, a proximal site, a distant site, and a logged forest. The local peoples' perception about the sustainability of NTFPs harvesting was analysed using logit regression analysis. A geographic information system was used to investigatet he influenceo f accessibilityt o the forest and to the marketplace from the villages on the forest products flow. Finally, the NTFPs value was compared with alternative land-clearance use and timber use values. The results indicate that the NTFPs extraction value is insufficient on its own to economically justify the rainforest biodiversity conservation in Sri Lanka, and perhaps elsewhere. There is also some doubt about the long term sustainability of forest products extraction. The study concludes that the rainforest conservation will have to be justified by a full total economic value (use and non-use values) appraisal, together with other scientific and ethical reasoning and cannot be promoted solely on the basis of non-timber extraction value.
36

Investigating the role of socioeconomic status in determining urban habitat quality for the house sparrow, Passer domesticus

Shaw, Lorna January 2009 (has links)
Urban areas are increasingly recognised as an important resource for wildlife, as studies have shown that gardens, parks and brownfield sites can contain high insect and plant diversity. Urban centres can also provide resources for species of conservation concern, and it is therefore important to monitor urban habitat quality and ensure the maintenance of urban biodiversity. However urban habitats are often difficult to monitor effectively due to access and sight restrictions in built up areas. This thesis investigates urban habitat quality in relation to an urban specialist species, the House Sparrow Passer domesticus. After considering the importance of urban habitats for biodiversity in general, I review the current status and distribution of the house sparrow in urban areas, with particular reference to the possibility that human socioeconomic status has influenced the decline of the species in some urban areas. I then consider which features of urban houses and gardens may provide a potential explanation for inter-city variation in habitat quality for urban birds. I present evidence that the age of houses; the prevalence of roof repairs; and the presence of extensive paved areas such as driveways are linked to areas with low levels of socioeconomic deprivation. I then use nationwide data to establish that house sparrows in English cities are more likely to occur in areas that are relatively deprived. Furthermore, analysis of land use data confirms that house sparrow occurrence decreases with increasing levels of building and paving, and increases with the area of green space available. However, house sparrow occurrence also appears to decrease with increasing garden area, a surprising finding given that gardens are important foraging habitats for urban birds. By radio tracking house sparrows in urban Bristol, I show that gardens are heavily utilised by house sparrows, but that those with a high proportion of paving are avoided. It appears that changes to areas with low levels of socioeconomic deprivation, notably an increase in paved areas, may have contributed to the urban decline of house sparrows in less deprived parts of English urban areas. These findings are discussed in relation to future urban planning requirements, and the need to mitigate for the detrimental effects of urban development on species of conservation concern. The contribution of large, nationwide datasets to the monitoring of urban habitats, and the implications of these findings for other urban species, including humans, are also highlighted.
37

Taxonomy and phytogeography of the Cactaceae of eastern Brazil

Taylor, Nigel Paul January 2000 (has links)
Eastern Brazil is a vast tropical area known to be rich in cactus diversity and endemism. Early explorers documented little of this due to the difficulty cacti present for preservation and description of living and museum specimens. Most taxa now known were discovered in the past 100 years, the majority being named and classified by horticulturists, whose activities greatly distorted their number and geographical range. Extensive literature, field and herbarium studies enabled better determination of generic and specific limits, correct nomenclature and details of distribution and ecology. Keys have been writte~ to facilitate identification of the 30 genera, 134 species and 43 heterotypic subspecies here recognised. In Eastern Brazil cactus biodiversity is concentrated in Bahia and Minas Gerais - each having > 90 taxa and 30 or more state endemics. The most likely explanation for this is greater complexity and discontinuity of habitats, leading to isolation of taxa and increased speciation. Cactus phytogeography lends support to recent hypotheses on historical plant migration routes in South America, while analysis of distribution patterns indicates> 94% of taxa as ± restricted to one of 3 major vegetation categories: (1) Mata atlantica, (2) Caatingas & Northern campos rupestres and (3) Cer~ados& South-eastern campos rupestres. Significantly, the campos rupestres are rich in endemic cacti, but divisable into two areas on the basis of cactus diversity. Of taxa included in category (2), > 70% belong to one of three major geographical-ecological areas, ranged west to east. Conservation status has been determined usmg information gathered for the above inventory and applying IUCN 1994 'Red List Categories' combined with Farjon & Page criteria (,phylogenetic distinction', 'ecological importance', 'genetic diversity'). As guidance to conservationists, prioritised shortlists of threatened taxa and Area Hotspots are provided. The South-eastern campos rupestres are of the greatest concern in terms of threatened taxa.
38

Effect of plant functional group removal on the soil microbial community diversity and composition

Marshall, Carolyn Bowers 05 1900 (has links)
A major objective of biodiversity-ecosystem functioning (BDEF) research is to determine the consequences of species loss, caused both naturally and anthropogenically, on the functioning of ecosystems. The impact of plant species loss on the soil microbial community has not received much attention even though soil microbes influence many important ecosystem functions such as decomposition and nutrient cycling. The objective of this research was to investigate how the functional group composition of the aboveground plant community influenced the belowground microbial community. Plant functional groups (graminoids, legumes and non-leguminous forbs) were removed from a northern grassland system in the Yukon Territory, Canada. One metre square plots had one of the three functional groups removed or left intact as a control and this was crossed with a fertilizer treatment and a fungicide treatment that targeted mycorrhizal fungi. After five seasons (2003-07) of implementing treatments the soil microbial community was analyzed using substrate-induced respiration (SIR, a measure of metabolic diversity) and phospholipid fatty acid analysis (PLFA, a measure of community composition). Plant functional group removal had almost no effect on the soil microbial community. The only response detected was an increase in stress (indicated by the PLFA stress ratio of cy19:0 to 18:1ω7c) which occurred when legumes were removed and fertilizer was not added, indicating that legumes had a positive effect on the nutrient status of microbes. Likewise, soil properties (total carbon, pH, moisture and nutrients) showed limited response to plant removals. Fertilization decreased the metabolic diversity of the soil microbial community. We detected no soil microbial or plant biomass response to the fungicide indicating that mycorrhizae had little influence in this system. Based on the low-productivity of the grassland, and the lack of response in both the soil properties and the microbial community, we hypothesize that the main determinants of the microbial community may be litter input. When litter decomposition rates are slow, such as in this northern system, five growing seasons may not be sufficient to detect the impact of a changing plant community on the soil microbes.
39

ECOSYSTEM FUNCTIONS AND PLANT COMMUNITY STRUCTURE OF URBAN SPONTANEOUS VEGETATION

Robinson, Sarah L. 11 December 2009 (has links)
This thesis set out to investigate the processes that determine the richness and composition of plant communities of spontaneously colonized derelict land in Metro Halifax, Nova Scotia. As urbanization rates continue to rise urban spontaneous vegetation (USV) communities are becoming more common. While typically considered to have no or negative economic value, USV contributes to a variety of ecosystem services not captured in current urban ecosystem models. Vascular plant composition and aboitic conditions of three urban communities (USV, forest and lawn) are described in Chapter 2. USV is diverse and unique, but the abiotic variables measured were not strong predictors of plant diversity. In Chapter 3, ecosystem services provided by the three urban habitats were quantified and compared, showing USV provides several ecosystem services that complement other urban habitats. Studies of urban biodiversity aid in the understanding of the effects of urbanization on biota and serve as a foundation for encouraging diverse communities of organisms within cities. Factors influencing the distribution and composition of USV communities could be vital for preserving native species by incorporating such knowledge into planning and urban development systems. USV should be considered an asset to urban greening initiatives, providing a low-cost, low maintenance approach to landscape planning, while providing a number of ecosystem benefits not provided by traditional elements of landscape design.
40

Parks, people, and power: the social effects of protecting the Ngel Nyaki Forest Reserve in eastern Nigeria

Macdonald, Fraser Ross January 2007 (has links)
The thesis outlines the impacts produced on local indigenous people by the protection of the Ngel Nyaki Forest Reserve in Taraba State, eastern Nigeria. After locating my work in various fields of literature and providing detailed background information on the area in which I conducted my fieldwork and the people who inhabit that area, I proceed onto the core of my thesis, which is two-fold. Firstly, I outline the impacts produced on the local people who inhabit the settlements surrounding the reserve. I elucidate the social, cultural, psychological, economic, and residential impacts of protecting the reserve. Second, I show how local people have adapted to these profound impacts. I show that they have negotiated the effects in various ways, including migration, livelihood diversification and shifting economic dependencies.

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