Thesis (Ph.D. (Environmental Science))--North-West University, Potchefstroom Campus, 2007.

Water is a scarce and precious resource in South Africa. Not only is the quality and quantity of water available limited by climatic conditions but these resources are often impacted by domestic and industrial effluents, as well as run-off from agriculture. Monitoring the aquatic environment helps to determine the impact of various pollutants. Chemical monitoring, important as it is, can only at best give a "snapshot" of water quality at a particular moment in time. Biomonitoring in particular forms a vital part of monitoring programmes as it gives a time integrated reflection of a particular pollutant or group of pollutants on the ecosystem. Although diatoms have long been studied in South Africa, as well as being used in the past to indicate water quality, the current suite of bioindicator organisms used in this country has not until recently included diatoms, or any autotrophic organisms for that matter. This body of work is presented with the aim of facilitating the use of diatoms as bioindicators of water quality in South Africa. Methods for the collection, preparation and analysis of diatoms have been collated and standardized. A number of European and other indices have been tested in diverse localities for use in indicating recent and historical water quality. The impact of diffuse mine effluent on diatom community structure has also been discussed. A new species common in impacted waters (i.e. a potential indicator species for these conditions) has been described and a guide to the common diatoms of South Africa is presented which, it is hoped, will be of use to those who wish to commence with a study of South Africa's diatom flora. The results of this study show that diatom indices are successful in reflecting both current and past water quality in South Africa. This result justifies the inclusion of diatoms with the current suite of bioindicator organisms as well as in national monitoring initiatives such as the River Health Programme. Concluding comments underline the importance of using diatoms as indicators, not only of water quality, but also as indicators of aquatic microorganism biodiversity, or loss thereof. The need for continued research in the fields of diatom ecology and taxonomy is also highlighted. / Thesis (Ph.D. (Environmental Science))--North-West University, Potchefstroom Campus, 2007.

Water is a scarce and precious resource in South Africa. Not only is the quality and quantity of water available limited by climatic conditions but these resources are often impacted by domestic and industrial effluents, as well as run-off from agriculture. Monitoring the aquatic environment helps to determine the impact of various pollutants. Chemical monitoring, important as it is, can only at best give a "snapshot" of water quality at a particular moment in time. Biomonitoring in particular forms a vital part of monitoring programmes as it gives a time integrated reflection of a particular pollutant or group of pollutants on the ecosystem. Although diatoms have long been studied in South Africa, as well as being used in the past to indicate water quality, the current suite of bioindicator organisms used in this country has not until recently included diatoms, or any autotrophic organisms for that matter. This body of work is presented with the aim of facilitating the use of diatoms as bioindicators of water quality in South Africa. Methods for the collection, preparation and analysis of diatoms have been collated and standardized. A number of European and other indices have been tested in diverse localities for use in indicating recent and historical water quality. The impact of diffuse mine effluent on diatom community structure has also been discussed. A new species common in impacted waters (i.e. a potential indicator species for these conditions) has been described and a guide to the common diatoms of South Africa is presented which, it is hoped, will be of use to those who wish to commence with a study of South Africa's diatom flora. The results of this study show that diatom indices are successful in reflecting both current and past water quality in South Africa. This result justifies the inclusion of diatoms with the current suite of bioindicator organisms as well as in national monitoring initiatives such as the River Health Programme. Concluding comments underline the importance of using diatoms as indicators, not only of water quality, but also as indicators of aquatic microorganism biodiversity, or loss thereof. The need for continued research in the fields of diatom ecology and taxonomy is also highlighted. / Thesis (Ph.D. (Environmental Science))--North-West University, Potchefstroom Campus, 2007.

Made available in DSpace on 2017-07-10T14:38:36Z (GMT). No. of bitstreams: 1 Thais Regina.pdf: 7142284 bytes, checksum: 2477288921627880d68c3803d0b9746f (MD5) Previous issue date: 2013-02-15 / Leguminosae Juss. is the third largest family of Angiosperms, comprising 727 genera and 19,325 species. Due the great N2 fixation in the soil, this family represents one of the leading families in floristic, phytosociological studies and recovery projects of degraded areas. However, some of these species have dormancy, which hinders germination. Such species variety can lead to difficulties in identification, particularly in sterile sample collection. Therefore this study aimed to develop a list with field tips, systematic identification keys and an illustrated guide, addressing the major vegetative diagnostic features of Leguminosae arboreal of Corredor de Biodiversidade Santa Maria, PR; as well as evaluate the germination test and treatments to overcome Seed dormancy of 10 Mimosa bimucronata (DC.) Kuntze. Samples have been collected in different areas of the Corridor. Legumes collected were photographed, recording morphological and vegetative stem rhytidome, staining the inner bark and / or sapwood, presence of gum shape of the leaflets, the presence of spines, glands, hairiness, and when present, flower and fruit. The samples were identified and housed into the Herbario da Universidade Estadual do Oeste do Paraná. For breaking dormancy were tested different treatment and also performed curve soaking to these seeds. Was prepared with a list of 29 tips field Leguminosae species found in the study area, which were made for one dichotomous key and a guide with plates illustrating the main diagnostic vegetative characteristics in order to assist in the identification of species of Leguminosae present in West of Paraná. The treatments with higher germination percentage and better germination speed were: immersion in sulfuric acid (10 min); soaking in acetone for 15 min, cutting the integument and immersion in water at 80oC (cooling in 24 hours), being the latter the most indicated. But all are efficient to overcome dormancy of M. bimucronata by increasing the percentage of germinated seeds and germination rate / Leguminosae é a terceira maior família de Angiospermas, compreendendo 727 gêneros e 19.325 espécies, representando uma das principais famílias em estudos florísticos e fitossociológicos. Tal riqueza pode ocasionar dificuldades na identificação, principalmente em coletas de amostras estéreis. O objetivo do presente estudo foi elaborar um guia ilustrado com dicas de campo, bem como uma chave de identificação abordando as principais características vegetativas diagnósticas das Leguminosae arbóreas do Corredor de Biodiversidade Santa Maria, o qual une a Faixa de Proteção do Lago de Itaipu ao Parque Nacional do Iguaçu. O corredor que reúne vários remanescentes de Floresta Estacional Semidecidual do sudoeste do Paraná e áreas reflorestadas. Foram coletadas amostras em diferentes áreas do corredor, sendo três remanescentes florestais (Parque Nacional do Iguaçu, Reserva Legal da Fazenda São José, Reserva Particular do Patrimônio Natural da Fazenda Santa Maria e matas ciliares do rio Bonito), e duas áreas reflorestadas (Faixa Seca e Faixa de Proteção do Lago de Itaipu). As leguminosas coletadas foram fotografadas ainda em campo, com câmera semiprofissional, registrando aspectos morfológicos vegetativos como tronco, ritidoma, coloração da casca interna e/ou alburno, presença de exsudato, formato dos folíolos, presença de acúleos, glândulas, pilosidade e, quando presentes, estruturas reprodutivas. As amostras foram identificadas e adicionadas ao Herbário da Universidade Estadual do Oeste do Paraná. Foram encontradas 29 espécies de Leguminosae, para as quais foram elaborados um guia com pranchas, ilustrando as principais características vegetativas diagnósticas, bem como uma chave dicotômica, a fim de auxiliar na identificação das espécies de Leguminosae presentes no sudoeste do Paraná. Características do tronco como ritidoma, casca interna e/ou alburno, formato e coloração dos folíolos, presença de exsudado, acúleos, pilosidade ou glândulas foram de grande valia em campo, pois permitiram a identificação das espécies de Leguminosae do Corredor de Biodiversidade Santa Maria