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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.
61

An evaluation of the potential and limitations of ecotourism as a vehicle for biodiversity conservation and sustainable development in the protected areas of India

Banerjee, Abhijit. January 2007 (has links)
Thesis (Ph.D.)--University of Delaware, 2007. / Principal faculty advisor: William F. Ritter, Dept. of Civil & Environmental Engineering. Includes bibliographical references.
62

Biological diversity in urban environments : positions, values and estimation methods /

Gyllin, Mats. January 2004 (has links)
Thesis (doctoral)--Swedish University of Agricultural Sciences, 2004. / Appendix consists of reprints of five manuscripts, four of which are co-authored with others. Includes bibliographical references. Also partially available online in PDF format; online version lacks appendix.
63

Testing the effectiveness of community-based conservation in conserving biodiversity, protecting ecosystem services, and improving human well-being in Madagascar

Andrianandrasana, Herizo January 2016 (has links)
This thesis is a scientific contribution towards evaluating the effectiveness of Community-based Conservation (CBC) in saving biodiversity, protecting ecosystem services and enhancing human well-being. The impact of CBC interventions carried out by Durrell Wildlife Conservation Trust over 109 villages in five conservation areas in Madagascar (Lake Alaotra, Baly Bay National Park, Menabe dry forest, Manombo rain forest, and Nosivolo River) since 1997, were retrospectively evaluated. The evaluation used a quasi-experimental design to contrast changes in a set of biodiversity and human wellbeing indicators in the intervention villages with 109 control villages, which were matched for a range of social and environmental attributes. In Chapter 2, findings suggest that over the period 2000-2014 the CBC approach has impacted the incidence of fire, resulting in a lower rate of increase in fire frequency. Although CBC interventions were not able to reduce forest loss, the rate of deforestation in CBC villages has generally been maintained at lower levels than in control villages. Political disruption, population size and travel cost (access and distance) to the villages were identified as important contributing factors towards an increase in the severity of fires and deforestation while access to mobile phones may help mitigate the pressures. In Chapter 3, results indicate that support to education through CBC interventions is significantly associated with improvements in educational attainment. However, analysis of the historical Index of Health Status at village level did not show evidence that provision of clean drinking water or other health interventions improved public health. In terms of human well-being (Chapter 4), there is no evidence that CBC interventions have any positive impact on the Multidimensional Poverty Index. Since poverty has been identified as a key factor reducing happiness, mutual trust, and power to change local decision-making, the claim that CBC will be effective in enhancing subjective well-being cannot be supported by the evidence from this study. According to the Index of Perception of Valued Ecosystem Services the declines in forest cover between 2000 and 2013 were observed by local people, with people in CBC villages demonstrating a greater propensity to note resulting changes in the provision of ecosystem services. This result could be of value when designing future CBC interventions. Maximum Entropy modelling using a set of environmental GIS layers was performed in Chapter 5 for predicting geographic distribution zones of four globally threatened species living exclusively in the five study areas. Results suggested that over the period 2000-2014 there has been a decline in habitat suitability expressed by a decrease in probability of presence of the species. Vegetation cover is predicted to be the most important factor affecting the variability of species distribution range. Potential factors responsible for the success of some actions and failure, others within the CBC approach are discussed and pragmatic recommendations are given at the end of the thesis. For example, transforming local associations into social enterprise could possibly motivate poorer households to join CBC efforts and thereby improve social and biodiversity impacts in the future.
64

Vliv druhového složení a prostorové struktury urbánní zeleně na biodiverzitu / The impact of species composition and spatial structure of urban green spaces on biodiversity

KLOUBCOVÁ, Petra January 2015 (has links)
In this thesis, avifauna in a town has been determined in detail, particularly the influence of the structure of urban green spaces on diversity of bird species. The study was conducted in a small spa town. We examined the influence of urban-rural gradient, density of buildings, and species composition and spatial structure of vegetation on the composition of the avifauna. We also assessed what social benefit for residents and visitors of the spa town comes from birdsong. The second part of this thesis deals with urban greenery in terms of positive impact on human well-being. The survey is applied to the chateau parks, especially visitor´s satisfaction, their ability to perceive diversity, their preferences, and evaluation of elements in the park.
65

The Effects of Global Changes on Fungal Communities: Measuring Biodiversity Belowground

Mueller, Rebecca 11 July 2013 (has links)
Global changes resulting from human activities, including elevated levels of greenhouse gases, enrichment of nitrogen and land use changes, have led to substantial losses in biodiversity of macroscopic organisms, such as plants and animals, but whether these changes will have similar impacts on microscopic organisms, such as bacteria and fungi, is less clear. I examined the impact of three of these global changes, including elevated carbon dioxide, increased soil nitrogen availability and large-scale deforestation, on the biodiversity of soil fungi in three separate ecosystems. The responses of fungi to global changes were variable across ecosystems and the experimental system and were not readily predicted by observed changes in the plant community. However, subtle shifts in the community composition of fungi were observed in response to all global changes. Whether these shifts will impact the ecosystem function of these systems in unclear, but previous studies suggest that even small changes in community dynamics can have large effects on important processes, such as nitrogen cycling and carbon storage. These findings indicate that soil fungi do respond to global changes, but additional research must be undertaken to examine the effects of these shifts. / 10000-01-01
66

Assessing the Impacts of Habitat Fragmentation on Biodiversity Across Scales: The Case of Thousand Island Lake, China

January 2018 (has links)
abstract: Habitat fragmentation, the loss of habitat in the landscape and spatial isolation of remaining habitat patches, has long been considered a serious threat to biodiversity. However, the study of habitat fragmentation is fraught with definitional and conceptual challenges. Specifically, a multi-scale perspective is needed to address apparent disagreements between landscape- and patch-based studies that have caused significant uncertainty concerning fragmentation’s effects on biological communities. Here I tested the hypothesis that habitat fragmentation alters biological communities by creating hierarchically nested selective pressures across plot-, patch-, and landscape-scales using woody plant community datasets from Thousand Island Lake, China. In this archipelago edge-effects had little impact on species-diversity. However, the amount of habitat in the surrounding landscape had a positive effect on species richness at the patch-scale and sets of small islands accumulated species faster than sets of large islands of equal total size at the landscape-scale. In contrast, at the functional-level edge-effects decreased the proportion of shade-tolerant trees, island-effects increased the proportion of shade- intolerant trees, and these two processes interacted to alter the functional composition of the regional pool when the total amount of habitat in the landscape was low. By observing interdependent fragmentation-mediated effects at each scale, I found support for the hypothesis that habitat fragmentation’s effects are hierarchically structured. / Dissertation/Thesis / Doctoral Dissertation Biology 2018
67

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. / Science, Faculty of / Botany, Department of / Graduate
68

Development and Management framework for the Gourits River Catchment

Griesel, Gerhard 20 November 2003 (has links)
This project forms part of a thesis for a Masters Degree in Landscape Architecture at the Department of Architecture, University of Pretoria. Not only is macro-scale or regional design a very important part of Landscape Architecture but a very interesting field that I wanted to explore through this project. Extensive studies have been made by the Cape Action Plan for the Environment (CAPE) on the biodiversity conservation for the Cape Floral Kingdom. A Biodiversity Strategy and action Plan for the Cape Floral Kingdom was developed. It is my intention to understand the Gourits River Catchment Area (further referred to as GRCA) as an interacting process, to interpret this as a value system and to designate appropriate land uses. / Dissertation (ML(Prof))--University of Pretoria, 2004. / Architecture / unrestricted
69

Restoring the biodiversity of canopy species within degraded spekboom thicket

Van der Vyver, Marius Lodewyk January 2011 (has links)
I investigated the return of plant canopy diversity to degraded spekboom thicket landscapes under restoration treatment. I attempted the reintroduction of five nursery propagated and naturally-occurring plant species in severely degraded Portulacaria afra Jacq. (spekboom) dominated thickets that have been subjected to a restoration method involving the planting of dense rows of P. afra truncheons for various time periods and also in degraded and intact thickets. I also planted nursery propagated P. afra cuttings. An average of 30 propagules of each species, were planted in each of the chosen areas in two distinct seasons that exhibited distinct rainfall peaks. Sixteen propagules of P. afra were also planted in each treatment only once. Propagules of the two thicket woody canopy species (S. longispina and P. capensis) showed a total survival of 1% and 9%, respectively. Survival of L. ferocissimum and R. obovatum was 19% and 70% and all propagules of P. afra survived. Analyses showed that survival is primarily tied to a species effect, with R. obovatum and P. afra showing significantly better survival than the other species. Within the other surviving few species a significant preference for overhanging canopy cover was observed. The results show little significance of restoration treatment for propagule survival, suggesting that a range of conditions is needed for the successful establishment of canopy species that likely involves a microclimate and suitable substrate created by canopy cover and litter fall, combined with an exceptional series of rainfall events. I found that the high costs involved with a biodiversity planting endeavour, and the low survival of propagules of thicket canopy plant species (P. afra excepted), renders the proposed biodiversity planting restoration protocol both ecologically and economically inefficient. Restoration success involves the autogenic regeneration of key species or functional groups within the degraded ecosystem. Heavily degraded spekboom-dominated thicket does not spontaneously regenerate its former canopy species composition and this state of affairs was interpreted in terms of a state-and-transition conceptual model. Floristic analyses of degraded, intact and a range of stands under restoration treatment for varying time periods at two locations in Sundays Spekboomveld revealed that the stands under restoration are progressively regenerating canopy species biodiversity with increasing restoration age, and that intact sites are still the most diverse. The high total carbon content (TCC) measured within the older restored stands Rhinosterhoek (241 t C ha-1 after 50 years at a depth of 50 cm) rivals that recorded for intact spekboom thickets, and the number of recruits found within older restored sites rivals intact sites sampled. 2 The changes recorded in the above- and belowground environments potentially identify P. afra as an ecosystem engineer within spekboom dominated thickets that facillitates the build-up of carbon above- and belowground and the accompanying changes in soil quality and the unique microclimate aboveground, which enables the hypothetical threshold of the degraded state to be transcended. This restoration methodology is accordingly considered efficient and autogenic canopy species return was found to be prominent after a period of 35-50 years of restoration treatment.
70

Exploring the linkages between biodiversity conservation and ecotourism in protected areas

Maciejewski, Kristine January 2012 (has links)
The prospect of using ecotourism to add value to conservation initiatives has frequently been stated. However, there is a general lack of information on the costs and benefits of biodiversity and its management, and how this can be influenced by the ecotourism industry. This study seeks to explore the value of biodiversity from the perspective of ecotourism in a hierarchical series of studies that move from the biome-level perspective down to the value of juveniles in ecotourism. Ecotourism plays a significant role in the establishment and management of Private Protected Areas (PPAs) and hence the opportunity to be added to the conservation estate. The financial opportunity to be found in ‘big five’ areas had led to an uneven biome coverage of PPAs which has resulted in the over-representation of certain areas and a skewed contribution towards national conservation targets. The landscape-use of PPAs have indicated that ecotourism operators are largely driven to achieve successful game-viewing sightings which has influenced management and affected the landscape use of PPAs, the stocking rate of species, the introduction of extralimital species, and management of flagship species. These management decisions are based on anecdotal sources and have been made at the expense of biodiversity and therefore apparent conflict exists between ecotourism and conservation objectives. This is based on lack of information: ecotourism operators, despite the large area they protect, have not realised their potential to contribute to conservation. It is therefore important to develop policy and incentives to motivate the establishment of PPAs in areas of high conservation significance in order to contribute to national conservation targets. Ecotourism should be used as a solution to provide important insights into tourist preferences which contribute to the larger debate of how to establish a balance between managing animal populations to ensure tourist satisfaction while supporting conservation. To ensure sustainability of PPAs, it is strongly recommended to manage PPAs more intensively with regards to PPA size, species stocking rates and landscape use. The presence of juveniles at an animal sighting significantly contributes to tourist satisfaction which suggests that the loss of juveniles may reduce the attraction. This is used to provide recommendations that using contraception to control elephant population numbers should be applied with caution as a management tool as it may be counterproductive by negatively impacting ecotourism. The findings from this study not only contribute to the conservation of biodiversity through the use of ecotourism, but will also ensure sustainability of the ecotourism industry and build capacity for sustainable living.

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