Thesis (Ph. D.)--University of Adelaide, 1986. / Includes bibliographical references (p. [i.e. leaves ] 267-277).

Thesis (M.A.)--University of Montana, 2008. / Title from title screen. Description based on contents viewed Aug. 27, 2008. Includes bibliographical references (p. 46-51).

No description available.

No description available.

Methane (CH$ sb4$) fluxes were measured in a range of peatland sites by a static chamber method in two regions of northern Canada, the Clay Belt of boreal Ontario and the Labrador Trough of subarctic Quebec. In both regions, seasonal mean water table position was the best predictor of mean CH$ sb4$ flux when microtopography was included in the analysis (r$ sp2$ = 0.73; p $<$ 0.01). The regression coefficients (slopes) were similar in both regions, suggesting a similar functional relationship between water table position and CH$ sb4$ flux; but the constants (intercepts) were different, implying a regional difference in climate or other biogeochemical factors. Broad-scale wetland classifications that do not account for microtopography and regional differences are inadequate for predicting CH$ sb4$ flux. / Vegetation and a suite of environmental variables in both regions were analyzed with multivariate statistics. Canonical correspondence analysis (CCA) showed that hydrology (water table position) explains most of the variability in bryophyte distribution, with chemistry (pore-water pH, Ca, Mg) as the second most important factor. The relative importance of the variables is reversed for vascular species in the Clay Belt; variables correlating with bryophyte and vascular species distribution are more similar in the Labrador Trough. Hydrology and chemistry are independent variables in both regions. CH$ sb4$ flux correlated strongly with hydrology in both regions, but not with chemistry. / Because of the strong correlation between bryophytes and CH$ sb4$ flux in the CCA analyses, a predictive model was developed using weighted averaging (WA) calibration. Optimum CH$ sb4$ flux values are highest for carpet/pool species and lowest for hummock species. No overlap in WA tolerances occurs between hummock and pool species, suggesting species at either end of the moisture gradient are the best predictors of CH$ sb4$ flux. Although the model works best within and not among regions, it has potential application in remote sensing of bryophytes for regional CH$ sb4$ budgets, paleoenvironmental reconstructions of CH$ sb4$ flux, and biological monitoring of future changes in CH$ sb4$ flux from climate-induced changes in peatland hydrology.

Thesis (MA)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: At a social, ecological and biological level it is important tha t we gain a better understanding of species distribution and the constraints to species distribution. Various modelling tools and approaches are available to provide this type of functionality. The GARP (Genetic Algorithm for Rule set Production) Modelling System (GMS) was selected because of its strong predictive modelling abilities and its ability to represent the results of model iterations in both a tabular and cartographic manner. A shortcoming in this system was identified in tha t it requires strong information technology skills in order to carry out the modelling process. This can be attributed to the lack of a user-friendly interface to the system. In order to address this a loosely coupled system was developed that provides an easy to use web-based front end to the GMS. This Integrated Modelling System extends the core functionality of the GMS by providing a system that provides detailed history for each analysis, allows fine tuning of the modelling process, integrates directly with a biodiversity database containing specimen observations, and provides a simple ‘wizard’ interface to the modelling process. / AFRIKAANSE OPSOMMING: Van ’n sosiale, ekologiese en biologiese standpunt is dit belangrik dat ons spesies verspreiding en die beperkings daarvan verstaan. ’n Verskeidenheid sagteware pakkette en metodologiee is beskikbaar om spesies verspreiding te modelleer. Die GARP (Genetic Algorithm for Rule set Production) sagteware was gebruik vir sy sterk voorspellingsvermoe, en sy kapasiteit vir kartografiese en tubulere tentoonstelling van model resultate. ’n Tekortkoming met hierdie stelsel was gei'dentifiseer - dit is nie gebruikersvriendelik nie en gebruikers het sterk informasie tegnologie vermoens nodig. Om hierdie tekortkominge aan te spreek was ’n sagteware program ontwerp wat van GARP gebruik maak deur middel van ’n webblaaier. Hierdie ge'integreerde stelsel bou op die basiese funksionaliteit van GARP om ’n werk omgewing te skep wat ’n gedetailleerde geskiedenis van elke model stoor, fyn beheer oor die model toelaat, direk met ’n bio diver siteits databasis koppel, en van ’n eenvoudige ’wizard’ stelsel gebruik maak om gebruikers opsies te bepaal.

No description available.

Thesis (MSc)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: Two key attributes of biodiversity, species richness and endemism are documented, analysed and mapped for the indigenous spermatophyte plant taxa of Namibia. A provisional diversity map is presented and transitional zones were shown to be the most significant for species richness. Distribution maps of the majority of endemic species in Namibia are shown together for the first time. Combinations of these data were used to map the overall distribution of endemic taxa, localities where significant numbers of local endemics occur, as well as the species that can be found in taxon phytogeographic centres. Recurring patterns are evident and areas of high species concentrations are catalogued. This thesis has contributed to the knowledge of the large number of plant taxa for .which Namibia is solely responsible, i.e. endemics restricted to within the political borders of Namibia. The mapping used an updateable, but permanent dataset on which future applications can be based. Examples of the uses of phytogeographic information proposed, include not only the traditional role in the identification of species in the herbarium, but also in creating a better basis for future policy especially in the development of land management strategies and conservation of Namibia's plant wealth / AFRIKAANSE OPSOMMING: Twee sleutelkenmerke van biodiversiteit, naamlik spesiesrykheid en endemisme word dokumenteer, ontleed, en karteer vir die inheemse saadplante van Namibië. 'n Voorlopige kaart van diversiteit word voorsien waaruit blyk dat oorgangsgebiede die belangrikste is vir spesiesrykheid. Verspreidingskaarte van meeste van die endemiese spesies in Namibië is word vir die eerste keer gesamentlik aangebied. Kombinasies van hierdie gegewens is gebruik om die algehele verspreiding van endemiese taksa, plekke waar betekenisvolle aantalle plaaslike endemiese taksa voorkom, sowel as die spesies wat voorkom in takson-geografiese sentrums, te karteer. Herhalende patrone is sigbaar, en gebiede met hoë specieskonsentrasies is gelys. Hierdie tesis het bygedra tot die kennis van 'n groot aantal plantsoorte waarvoor Namibië alleen verantwoordelik is, synde endemiese soorte wat beperk is tot binne die polieke grense van Namibië. Die kartering het 'n opdateerbare, maar permanente, databasis gebruik waarop toekomstige aanwendings baseer kan word. Voorbeelde van die gebruike van plantgeografiese inligting wat voorgestel is, sluit in tradisionele gebruik in die identifikasie van species in die herbarium, sowel as die skepping van 'n beter fondament vir toeskomstige beleid in veral die ontwikkeling van bestuurstrategië en bewaring van Namibia se planterykdom

Thesis (Ph.D.)--University of Wollongong, 2007. / Typescript. Includes bibliographical references: p. 128-139.

Thesis (Ph. D.)--Duke University, 2007. / Includes bibliographical references.