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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.
1

The allometry of algal growth and respiration

Tang, Evonne P. Y. (Evonne Pui Yue) January 1995 (has links)
A knowledge of the allometry of algal growth and respiration can be applied to biomass-size distribution models which are in turn used in the prediction of fish yield and ecosystem studies. However, the scaling exponents reported in the literature are variable. This variation may be attributed to differences in the expression of cell size and phylogeny, but could also reflect small sample size which underlie most published regressions. This thesis establishes the allometry of algal growth and respiration based on a larger sample taken from the literature, and evaluates the effects of differences in gross taxonomy and in the expression of cell size on these relations. Allometric relations based on cell carbon appear more consistent with relations from other taxa than those based on cell volume, reflecting the size dependence of algal elemental composition which does not occur in most other taxa. The allometric relation of algal respiration (R in pl O$ rm sb2 cdot cell sp{-1} cdot hr sp{-1})$ was found to be R = 0.030C$ sp{0.93}$ where C is cell carbon content in pg C$ rm cdot cell sp{-1}$. Among the 6 divisions studied (Chlorophyta, Chrysophyta, Cyanophyta, Euglenophyta, Pyrrophyta, Rhodophyta), chlorophytes, euglenophytes and rhodophytes exhibited different respiration-size relation but separate relations were not developed for each of those groups due to patterns in residuals or small sample sizes. The specific rate of algal growth ($ mu$ in divisions$ cdot$day$ sp{-1}$) also depends on size and it is found to be $ mu$ = 3.45C$ sp{-0.21}.$ All taxa studied here (Chlorophyta, Chrysophyta, Pyrrophyta) have similar scaling exponents for growth but Pyrrophyta have significantly lower growth rates than other algae of similar size.
2

The allometry of algal growth and respiration

Tang, Evonne P. Y. (Evonne Pui Yue) January 1995 (has links)
No description available.
3

The relationship between canopy structure, light dynamics and deciduousness in a seasonal tropical forest in Panama : a multiple scale study using remote sensing and allometry /

Bohlman, Stephanie Ann. January 2004 (has links)
Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 165-194).
4

Relationship between allometric variables and biomass in western juniper (Juniperus occidentalis) /

Sabin, Breanna S. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 42-44). Also available on the World Wide Web.
5

Carbon sequestration in cultivated and uncultivated Vachellia karroo sites in Tankwa Karoo National Park

Phophe, Paulina Avhavhudzani January 2021 (has links)
Magister Scientiae (Biodiversity and Conservation Biology) - MSc (Biodiv and Cons Biol) / The Succulent Karoo Biome (SKB) in South Africa is widely reputed to house Earth’s greatest diversity of succulent plants. It is also famous for spectacular displays of annual flowers after good rains. The area experiences winter rainfall which infrequently exceeds 100 mm per annum but certain parts of the SKB can get 250 mm. Irrigated agriculture on a large scale was therefore not a viable option when European farmers began colonizing the land. The land was conquered from the indigenous Khoekhoe herders and San hunter-gatherers, South Africa’s first peoples. The biome underwent extreme transformation in the last 200 years following colonisation which resulted in homogenization of the landscape and extinction of many succulents thus reducing biodiversity.
6

Light intensity influences on algal pigments, proteins and carbohydrates: implications for pigment-based chemotaxonomy

Unknown Date (has links)
Phytoplankton Chlorophyll a (CHLa), total protein, colloidal carbohydrates, storage carbohydrates and taxonomic pigment relationships were studied in two cyanophytes (Microcystis aeruginosa and Synnechococcus elongatus), two chlorophytes (Dunaliella tertiolecta and Scenedesmus quadricauda), one cryptophyte (Rhodomonas salina), two diatoms (Cyclotella meneghiniana and Thalassiosira weissflogii) and one dinophyte (Amphidinium carterae) to assess if algal biomass could be expressed in other indices than just chlorophyll a alone. Protein and carbohydrates are more useful currencies for expressing algal biomass, with respect to energy flow amongst trophic levels. These phytoplankton were grown at low light (LL = 37 (So(Bmol photons m-2 s-1), medium light (ML = 70-75 (So(Bmol photons m-2 s-1), and high light (HL= 200 (So(Bmol photons m-2 s-1). / Even though pigment per cell increased with increasing light intensity, statistically light had very little effect on the CHL a : taxonomic marker pigment ratios, as they covaried in the same way. Protein, colloidal carbohydrates and storage carbohydrates per cell all increased with increasing light intensity, but they did not covary with CHLa. Statistical data showed that light intensity had a more noticeable effect on protein: CHL a, colloidal carbohydrate: CHLa, storage CHO: CHLa, therefore a general mathematical expression for these relationships cannot be generated. This study showed that light intensity does have an influence on these biomass indices, therefore, seasonal and latitudinal formulas may be required for meaningful algal biomass estimation. However, more studies are needed if that goal is to be realized. / While studying the effects of light intensity on algal pigment content and concentration, a new pigment was isolated from a cyanophyte (Scytonema hofmanii) growing between 300-1800 (So(Bmol photons¨m-2¨s-1 and from samples collected in areas of the Florida Everglades. This pigment was characterized and structurally determined to possess indolic and phenolic subunits that are characteristic of scytonemin and its derivatives. In addition, the pigment has a ketamine functionality which gives it its unique polarity and spectral properties. Based on the ultra violet/visible absorbance data, this pigment was postulated to be protecting the chlorophyll a and cytochrome Soret bands as well as a and (Sb (Bbands of the cytochromes (e.g. cytc-562) in the photosynthetic unit. / by Cidya Grant. / Thesis (Ph.D.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.
7

Arquitetura e alometria de espécies arbóreas em uma floresta estacional subtropical / Architecture and allometry of tree species in a subtropical seasonal forest

Costa, Malcon do Prado 22 January 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aim of this study was to describe some architectural models and study their behavior in vegetation structure, allometric patterns and their growth dynamics to support management activities and conservation of tree species in seasonal forest of Santa Maria (RS). In the first chapter a descriptive analysis was performed of the species present in the fragment and its architectural models. A list of 53 species of tree flora of a Subtropical feasonal forest in Santa Maria (RS), distributed in 45 genera and 28 families in the local flora gifts inventoried. In the second chapter a study of the species and the behavior of architectural models were performed in the vertical structure of the community. When an association was detected between species and their architectural models with vertical forest strata. The natural disturbances in the architecture of the forest as the formations of gaps provide explanations for the persistence of species with irregular distribution in the vertical structure of the Forest. In the third chapter of the mechanical designs of architectural models have been studied and have been selected among a few variables, which best explain the increase in basal area of individual trees in the remaining. The variables that best explained the increase in basal area of trees were diameter at breast height, crown diameter and salience index, and the architectural models of categorical variable increased the efficiency of regression. The study of vegetation dynamics from the behavior of groups of species of architectural models are promising for planning activities of forest ecosystems. / O objetivo geral deste trabalho foi descrever alguns modelos arquiteturais e estudar o comportamento dos mesmos na estrutura da vegetação, seus padrões alométricos e dinâmica de crescimento para subsidiar atividades de manejo e conservação de espécies arbóreas em Floresta Estacionais de Santa Maria (RS). No primeiro capítulo foi realizada uma análise descritiva das espécies presentes no fragmento e de seus modelos arquitetônicos. Uma lista de 53 espécies da flora arbórea de uma Floresta Estacional Subtropical de Santa Maria (RS), distribuídas em 45 gêneros e 28 famílias foram inventariadas. No segundo capítulo foi realizado um estudo das espécies e o comportamento dos modelos arquitetônicos na estruturação vertical da comunidade. Detectando-se uma associação entre as espécies e seus modelos arquitetônicos com os estratos verticais da floresta. Os distúrbios naturais na arquitetura da floresta, como as formações de clareiras, fornecem explicações para a permanência das espécies com distribuição irregular na estrutura vertical da floresta. No terceiro capítulo foram estudados os desenhos mecânicos dos modelos arquitetônicos e foram selecionadas, dentre algumas variáveis, as que melhor explicam o incremento em área basal de árvores individuais no remanescente. As variáveis que melhor explicaram o incremento em área basal das árvores foram o diâmetro a altura do peito, o diâmetro da copa e o índice de saliência, sendo que a variável categórica dos modelos arquiteturais aumentou a eficiência da regressão. O estudo de dinâmica da vegetação a partir do comportamento de grupos de espécies de modelos arquitetônicos são promissores para atividades de planejamento de ecossistemas florestais.

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