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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.
11

Improving environmental sustainability in Hong Kong : the role of biodiversity /

Cheung, chi-ming. January 2002 (has links)
Thesis (M. Sc.)--University of Hong Kong, 2002. / Includes bibliographical references.
12

Habitat quality and assessing risks to avian biodiversity /

Barczak, Mary J. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 1996. / Typescript (photocopy). Includes bibliographical references (leaves 41-46). Also available via the World Wide Web.
13

Freshwater fungi biodiversity, origins and molecular taxonomy /

Dhanasekaran, Vijaykrishna. January 2005 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2005. / Title proper from title frame. Also available in printed format.
14

A description of floral diversity in the southern Appalachians with forest management considerations for conservation /

Brown, Maryfrances McGrath. January 1994 (has links)
Report (M.F.)--Virginia Polytechnic Institute and State University, 1994. / Includes bibliographical references (leaves 136-149). Also available via the Internet.
15

The relative performance of surrogate measures for viable populations

Solomon, Mariaan 06 December 2006 (has links)
Please read the abstract in the section 00front of this document / Dissertation (MSc (Zoology))--University of Pretoria, 2006. / Zoology and Entomology / unrestricted
16

The dispersal paradox : can lowland granivorous mice also disperse the seeds they devour?

Gwynne-Evans, David 23 February 2017 (has links)
The relationship between two rodent species and the Cape Reed (Willdenowia incurvata) were examined. Many studies have focussed on the role of rodents as predators of plant seeds. However, it seems that certain rodents may actually perform a crucial role in the dispersal of plants. Experiments to uncover the dispersal mechanism were carried out. Also examined is the role of the appendages present on the Restio seeds, possibly as energy-rich rewards for dispersal for the rodents. It was found that the Restio may be dependent on seed-dispersing rodents, although this mutualism is not so important in fragmented habitats.
17

Dispersal, gene flow, niche divergence and local adaptation in the hyper-diverse ruschioid Aizoaceae: testing alternative modes of speciation in the Knersvlakte quartz field flora of the Succulent Karoo, South Africa

Musker, Seth January 2017 (has links)
What are the roles of alternative modes of speciation in the generation of biological diversity? This question is fundamental to the debate surrounding the origins of extraordinarily diverse regions and clades. Diversification in the Cape flora of South Africa has been intensively studied owing to its remarkable diversity, for which significant roles for both ecological and non-ecological speciation have been invoked as drivers. However, much of this research has focused on the mesic fynbos vegetation, with far less attention paid to its neighboring biodiversity hotspot, the arid Succulent Karoo (SK), which has hosted the spectacular radiation of the ecologically dominant ruschioid Aizoaceae, a succulent group which exhibits extreme morphological diversity and convergence. This thesis focused on ruschioid Aizoaceae in the Knersvlakte, a small region of the SK which holds a diverse and endemic-rich flora specially adapted to the ecologically unusual quartz fields - whose patchy distribution in the landscape suggests that diversification may have been facilitated by divergence of populations isolated on these 'environmental islands' in a similar fashion to serpentine systems such as those in California - and continues from previous work on the Knersvlakte-endemic ruschioid genus Argyroderma which supported an adaptive radiation in allopatry hypothesis. A population genomic approach was used to investigate the scale of seed dispersal (which is thought to be very limited due to the group's highly specialized ballistic dispersal mechanism) as well as correlates of population divergence in two ruschioid quartz-field specialists with very different growth forms (the shrubby Ruschia burtoniae versus the dwarf Conophytum calculus) and which co-occurred at four sites distributed throughout the Knersvlakte. This, in combination with ecological and experimental transplant data to test the adaptive underpinning of edaphically-driven community structure, ecological isolation and niche divergence in these and other quartz field species, made it possible to tease apart the roles of local adaptation and limited dispersal in driving gene flow and speciation in the system. Quartz fields were found to be a highly insular habitat with strong internal edaphic community structure, suggesting that they represent an environmental island system. In addition, intrinsic dispersal ability was very poor in the specialist shrub, which showed complete genetic isolation between the four populations separated by just 17-42 km. This species showed strong local adaptation between the populations as well as some evidence that this inhibited gene flow, though it is more likely that dispersal limitation allowed for fundamental niche divergence. In contrast, the dwarf showed surprisingly good dispersal ability and consequent weak genetic structure, which accounted for the lack of edaphic local adaptation between the populations. The study showed that, contrary to expectation, not all ruschioid Aizoaceae are poor dispersers, and also suggested that the likelihood of ecological speciation in response to edaphic heterogeneity is contingent on dispersal ability. Strongly limited dispersal may thus have contributed to the group's diversification either through non-adaptive radiation or edaphically driven adaptive radiation, but other factors are more likely to have driven diversification in sections of ruschioid Aizoaceae that possess mechanisms of long-distance dispersal. Future work might focus on inferring the scale of dispersal (e.g. based on morphological traits) and whether it predicts diversification rates. Finally, the lack of morphological variation in R. burtoniae belies its strong ecological and genetic divergence; in light of this, systematists are encouraged to investigate cryptic speciation in the group.
18

The role of local government in the conservation of biodiversity

Kelly, Andrew Harley Heron. January 2004 (has links)
Thesis (Ph.D.)--University of Wollongong, 2004. / Typescript. Includes bibliographical references: leaf i-lxiv.
19

Biodiversity prospecting agreements evaluating their economic and conservation benefits in Costa Rica and Peru /

Crook, Carolyn, January 2001 (has links)
Thesis (Ph. D.)--University of Toronto, 2001. / Includes bibliographical references (leaves 161-181).
20

Selecting species as indicators of ecological integrity a conceptual model based on mammals of Algonquin Provincial Park, Ontario, Canada /

Kassel, Samantha J. January 1998 (has links)
Thesis (M.E.S.)--York University, 1998. / Typescript. Includes bibliographical references (leaves 93-104). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pMQ27357.

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