Thesis (M.A.)--University of Waterloo, 1994. / Includes bibliographical references (p. 131-142).

Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (M.A.)--The University of North Carolina at Greensboro, 2008. / Directed by Roy Stine; submitted to the Dept. of Geography. Title from PDF t.p. (viewed Apr. 13, 2010). Includes bibliographical references (p. 58-64).

Thesis (MSc)--University of Stellenbosch, 2006. / Bibliography. Also available via the Internet.

Thesis (M.Sc. (Environmental Science)) - Rhodes University, 2009.

Orientador: André Olmos Simões / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-26T03:43:07Z (GMT). No. of bitstreams: 1 Scatigna_AndreVito_M.pdf: 3305692 bytes, checksum: 2c9fe2f311dab327995537083164034a (MD5) Previous issue date: 2014 / Resumo: Philcoxia é um gênero recentemente descrito, composto por quatro espécies reconhecidas e uma nova espécie, endêmicas das formações arenosas do Cerrado e Caatinga. Por conta de sua raridade e da vulnerabilidade de seu habitat, o gênero pode ser considerado criticamente ameaçado de extinção. Recentes evidências filogenéticas sustentam a inclusão do gênero na tribo Gratioleae (Plantaginaceae). Entretanto, as relações de Philcoxia dentro da tribo continuam controversas desde sua descrição. Apresentamos, aqui, estudos filogenéticos de Gratioleae, focados no teste do monofiletismo de Philcoxia, suas relações interespecíficas e seu posicionamento. As análises filogenéticas foram feitas pelos métodos de Máxima Parcimônia e inferência Bayesiana. Sequências dos íntrons rpl16, rps16 e trnL e do espaçador trnL-trnF, todas do DNA cloroplastidial, foram analisadas, incluindo 31 amostras, entre as quais quatro espécies de Philcoxia, 23 outras espécies de Gratioleae e mais quatro táxons (grupo externo) de Plantaginaceae. As espécies de Philcoxia formam um clado fortemente sustentado, irmão de Stemodia stellata. Philcoxia minensis é mais próxima de P. rhizomatosa e P. bahiensis é mais próxima de P. tuberosa. O clado que inlcui Philcoxia e S. stellata é relacionado aos clados formados por Achetaria, Scoparia e alguns representantes de Stemodia. Realizamos, também, o desenvolvimento e caracterização de marcadores microssatélites inéditos para estudos em genética de populações voltados para conservação de P. minensis. Pares de iniciadores foram desenhados para 27 locos de microssatélites e testados em 30 indivíduos de uma população de P. minensis e em quatro indivíduos de P. bahiensis. Dezessete locos foram amplificados com sucesso, doze dos quais se mostraram polimórficos. Os 12 marcadores polimórficos serão usados em futuros estudos relacionados ao sistema de reprodução e à diversidade genética de P. minensis e são potenciais ferramentas para esses estudos com P. bahiensis. Além disso, a nova espécie Philcoxia rhizomatosa é descrita e ilustrada. Ela apresenta folhas maiores que outras espécies do gênero e também possui um rizoma bastante conspícuo e ramificado. Esta nova espécie é aparentemente endêmica de um areal em Botumirim, Minas Gerais, em vegetação de transição entre Cerrado e Caatinga. Testes de carnivoria positivos sugerem que P. rhizomatosa é uma planta carnívora / Abstract: Philcoxia is a recently described genus, composed of four currently recognized species and one additional new species, endemic to the Brazilian sandy formations of the Cerrado and Caatinga. Due to its rarity and the vulnerability of the formation where it occurs, this genus could be treated as critically endangered. Recent evidences from molecular phylogenetics support the inclusion of the genus within the tribe Gratioleae (Plantaginaceae). The affinities of Philcoxia within the tribe, however, have been controversial since it was first described. Here, we present a phylogenetic analysis of Gratioleae, focusing on the test of the monophyly of Philcoxia, its interspecific relationships and its placement. Phylogenetic analyses were conducted using Maximum Parsimony and Bayesian approaches. Sequence data from rpl16, rps16 and trnL introns and trnL-trnF intergenic spacer were analysed, including 31 samples representing four species of Philcoxia, 23 additional Gratioleae species and four outgroup taxa from Plantaginaceae. Philcoxia species form a strongly supported clade, sister of Stemodia stellata. Philcoxia minensis is closely related to P. rhizomatosa and P. bahiensis is closer to P. tuberosa. The clade Philcoxia plus S. stellata is related to clades formed by Achetaria, Scoparia and Stemodia representatives. We also developed and characterized new microsatellite markers as tools for further studies in population genetics aiming the conservation of P. minensis. Primer pairs were developed for 27 microsatellite loci and validated in 30 individuals of P. minensis from a natural population and tested in four idivividuals from a natural population of P. bahiensis. Seventeen loci successfully amplified, twelve of which were polymorphic. The 12 polymorphic markers are suitable for studies concerning mating system and genetic diversity of P. minensis and also may be usefull tools to study similar issues regarding its related species, P. bahiensis. In addition, the new species Philcoxia rhizomatosa is described and illustrated. It has bigger leaves than other species in the genus and presents a conspicuous and branched rhizome. This new taxa is possibly endemic to a sand patch in the transition vegetation between the Cerrado and the Caatinga in Botumirim, Minas Gerais, Brazil. Tests for carnivory were performed and showed activity of phosphatase, suggesting that P. rhizomatosa is a carnivorous plant / Mestrado / Biologia Vegetal / Mestre em Biologia Vegetal

M.Sc. / Invasive species are a considerable threat to ecosystems globally, especially on islands where species diversity can be relatively low. Understanding the drivers of invasion is the first step towards an adequate management plan. Although Darwin’s naturalisation hypothesis has fuelled our understanding in this regard, several studies provided mixed results, suggesting that invasion success might be context-dependent. The main objectives of this study are two-fold: (1) testing Darwin hypothesis on Robben Island, and (2) investigating the relative role of invasive alien plants on phylogenetic diversity (PD) loss in native community. I sampled extensively the flora of the island, and using a Bayesian analysis, I reconstructed its phylogeny based on two plastid DNA loci, rbcLa and matK. I also surveyed a total of 127 plots of 50 x 50 m (i.e. local communities) where species presence/absence was recorded. Analysing phylogenetic patterns of the native and invasive floras at both regional (phylogeny level) and smaller scales (plots level), I found that invasive species are, on average, more distantly related to the native communities, giving strong support to the hypothesis tested. Furthermore I found that native communities have accumulated lower PD than alien communities; and that local communities are more overdispersed than expected. These findings suggest that competitive interactions might be the major ecological forces shaping plant communities, with the possibility of alien being higher competitors than native, and therefore decreasing native plant diversity. The implications of these findings for the recovery of native plants are also discussed. Key words: Invasion biology - Darwin’s naturalisation hypothesis - Phylogenetic diversity - Community structure - Conservation - Robben Island, South Africa.

No description available.

Subtropical Thicket is the dominant vegetation biome in the Eastern Cape, and extends through to parts of the Western Cape. It is dominated by Portulacaria afra (spekboom), a woody succulent plant recognised for its importance as an ecosystem engineer and its carbon sequestration potential. Due to excessive grazing from domestic stock, spekboom has been completely removed from some areas. The Subtropical Thicket Restoration Programme (STRP) initiated a large scale restoration programme of planting spekboom cuttings in these degraded areas. Their efforts have been met with varying levels of success and improvement of the programme relies on continuous monitoring and scientific evaluation. I investigated the influence of selected soil properties on spekboom growth, mortality and landscape distribution, at both restoration sites and natural intact areas, and through experiments. Site or location was the most important factor influencing spekboom success at restoration plots, whereby sites in the eastern end of spekboom distribution perform better. Moving westwards slope orientation emerged as an important factor, whereby north facing slopes are preferred by spekboom. Although high levels of soil salinity (NaCl) restricted spekboom growth and affected its health, it could tolerate the levels it was exposed too. Soil pH, above 7, and phosphorous concentration, above 70 mg.kg-1, were the only limiting factors to spekboom survival found in the restoration sites. This preference for acidic soils was mirrored in intact Thicket. However in general, soil is not a major factor influencing spekboom growth and distribution, and spekboom is tolerant of a wide range of soil conditions. Spekbooms constraint is most likely a function of climate, which varies greatly across the biome. This study answered some vital questions regarding the possible influence of soil in spekboom growth and distribution. It disapproved the theory that a catena effect may be responsible for the lack of spekboom growing in bottomland areas. The study also indicates and supports the versatility of spekboom as a plant for restoring degraded lands across a range of different geologies and soil types. To maximise spekboom survival rates, restoration efforts should be focussed towards the eastern end of its distribution and to avoid planting in soils with pH levels higher than 7.