• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 13
  • 13
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 30
  • 13
  • 9
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 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

Stem form, height and volume models for teak in Tanzania /

Van Zyl, Louis. January 2005 (has links)
Thesis (MScBosb)--University of Stellenbosch, 2005. / Bibliography. Also available via the Internet.
2

Variation of fruit, seed and seedling characteristics among provenances of Tectona grandis Linn.f

Yingvanasiri, T. January 1976 (has links)
No description available.
3

An economic analysis of the conservation policy for teak in Thailand, 1957-1969

Sombun Suphasin. January 1973 (has links)
Thesis (M. Econ.)--Thammasat University. / Includes bibliographical references (leaves 125-127).
4

The teak industry in North Thailand the role of a natural-resource-based export economy in regional development /

Banasopit Mekvichai, January 1988 (has links)
Thesis (Ph. D.)--Cornell University, 1988. / Typescript. Vita. Includes bibliographical references (leaves 295-309). Also issued in print.
5

The teak industry in North Thailand the role of a natural-resource-based export economy in regional development /

Banasopit Mekvichai, January 1988 (has links)
Thesis (Ph. D.)--Cornell University, 1988. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 295-309).
6

A critical study of modern methods of forest management and yield regulation, with special reference to their application to the teak forests of Burma

Kyi, Maung January 1959 (has links)
No description available.
7

Otimização do crescimento e desenvolvimento de teca (Tectona grandis Linn f.) in vitro / Optimization of teak (Tectona grandis Linn f.) growth and development in vitro

Nery, Felipe Uassurê 11 November 2011 (has links)
O crescente aumento no uso da micropropagação de teca como forma de produção de clones com qualidades genotípicas e fenotípicas selecionadas a partir de árvores de elite, determinou a importância desse método, pois origina plantações com maior qualidade e uniformidade, agregando maior valor ao preço da madeira no mercado. O uso de sementes para a obtenção de mudas é uma técnica menos onerosa, porém resulta em plantas com tamanhos desiguais e não há um padrão na qualidade da madeira, essa técnica depende também da época de produção de sementes e, portanto é restrita a um período do ano. A micropropagação permite a clonagem em larga escala das árvores de elite em tempo e espaço reduzidos, podendo ser realizada em qualquer época do ano, além disso, permite a formação de mudas totalmente livres de pragas e patógenos. Faz-se necessário, maiores estudos com meio de cultura para Tectona grandis, pois os materiais relacionados a esse assunto são escassos. Para que a técnica do cultivo in vitro da teca seja incrementada, objetivou-se nesse experimento, otimizar o crescimento dos explantes de três clones diferentes, testando a eficiência de 6 meios de cultura com diferentes formulações nutricionais e constatar qual deles apresenta a melhor resposta para cada clone. O estudo contou com 6 tratamentos (MS, Básico, M1, M2, M3 e M4), durante oito épocas de avaliação (0, 7, 14, 21, 28, 35, 42 e 49 dias), para três clones de Tectona grandis (61, 62 e 68), com três repetições por tratamento/clone, utilizando o delineamento experimental inteiramente casualizado. A avaliação do crescimento foi feita por meio do peso de matéria fresca (PMF), matéria seca (PMS) e a taxa de crescimento relativo (TCR) proporcionado pelos meios. O PMF foi usado para obtenção do PMS e cálculo da TCR. Baseado nos valores do PMS obtidos, para o clone 61, constatou-se a formulação do meio Básico (PMS = 0,38 g), como a mais eficiente. Para o clone 62, o meio mais responsivo foi M4 (PMS = 0,47 g) e no clone 68, destacou-se o meio M3 (PMS = 0,71 g). Quanto a TCR, não foi encontrada diferença estatística significativa para nenhum dos 6 meios de cultura levando-se em conta os três clones. / The increasing use of teak micropropagation as a way of producing clones with genotypic and phenotypic qualities selected from elite trees, established the importance of this method, it leads to higher crop quality and consistency, adding more value to the price of wood business. The use of seeds to obtain seedlings has a less cost, but it results in plants with unequal sizes and wood quality without a pattern. This technique also depends on the time of seed production and therefore is restricted to a year period. Micropropagation allows cloning elite trees in large-scale and reduced time and space. It can be performed at any time of year, in addition, allows the formation of plants totally free of pests and pathogens. It is necessary more studies with culture medium for Tectona grandis, because the materials related to this subject are scarce. To increase the technique of teak in vitro cultivation, this experiment aimed to optimize the growth and development of explants from three different clones, testing the effectiveness of six culture media with different nutritional formulations and find which one offers the best answer to each clone. The study included six treatments (MS, Basic, M1, M2, M3 and M4) for eight periods (0, 7, 14, 21, 28, 35, 42 and 49 days) for three clones of Tectona grandis (61, 62 and 68) with three replicates per treatment/clone, in a randomized experimental design. The growth assessment was performed by the fresh matter weight (FMW), dry matter weight (DMW) and relative growth rate (RGR) provided by the media. The FMW was used to obtain the DMW and to calculate RGR. Based on DMW values obtained for clone 61, was found that the formulation of Basic medium (DMW = 0.38 g) was the most efficient. For clone 62, the most responsive medium was M4 (DMW = 0.47 g) and to clone 68, M3 (DMW = 0.71 g) was the highlighted medium. As the RGR, it was found no statistically significant difference for any of the six culture media taking into account the three clones.
8

Carbon storage of Panamanian harvest-age teak (Tectona grandis) plantations

Kraenzel, Margaret. January 2000 (has links)
Reforestation is being considered as a mitigation option to help combat the climate change predicted to result from atmospheric carbon dioxide pollution. Forestry-based carbon storage projects are being introduced in many tropical countries, and assessment of species-specific carbon storage potentials is made difficult by a lack of species-level information. This study focuses on teak (Tectona grandis), to measure many of the characteristics affecting the carbon storage potential both of the trees themselves and of the plantations they are in. Root-to-shoot ratio, above- and belowground biomass, as well as tissue carbon content were measured in 20-year-old teak trees in Panamanian plantations. A regression relating diameter at breast height (DBH) to total tree carbon storage for trees of various sizes was developed. To scale up to the plantation level, this regression was used to estimate the carbon storage of the trees of four plantations. Litter, undergrowth, and soil were studied to estimate carbon storage in these compartments. These estimates were collated to form a global estimate of carbon storage in Panamanian harvest age teak plantations. Various methods of calculation of carbon storage in short-rotation plantations are discussed. This work will allow greater precision in the assessment of carbon storage in individual plantations.
9

Soil characterisation for teak (Tectona grandis) plantations in the Nzara district of Southern Sudan

Ombina, Christian Ahmed 12 1900 (has links)
Thesis (MScFor (Forest and Wood Science))--Stellenbosch University, 2008. / The characterization of soils in Nzara District of Southern Sudan in comparison to other tropical teak growing countries (Tectona grandis) – in respect of extensions to existing and/or the establishment of new teak plantations – were done by firstly considering the soils of three existing plantations: Yoboa, Mabarizinga and Nagondi, and secondly by considering soils outside and inside the existing teak plantations in respect of land uses. From these soil characterizations, it emerged that considerable positive returns can be expected from teak plantings in the area as an investment, provided that appropriate site management is implemented. Climatic data of the Nzara area compared favorably with the climatic range of areas where teak grows naturally and the world’s dominant producers: mean annual rainfall 1350-1600 mm with a distribution over 6-8 months compares well with that of Myanmar (1250-3750 mm) and Indonesia (1511-2108 mm) both with at least 3 months of dry season. The mean annual temperature of 28-350C compares well with 15-410C and 30-320C of Myanmar and Indonesia respectively. The Yoboa and Mabarizinga sites should be prioritized as they appear slightly more suitable than the Nagondi site. All three sites have a dominant soil texture of Sandy Clay Loam similar to Sandy Loam of most areas of other tropical countries where teak is growing well (such as India, Indonesia and Nigeria). Yoboa and Mabarizinga however distinguish themselves by having the highest soil pHwater values range from 6.4±0.56 and 6.04±0.7 in top soils; 5.91±0.5 and 5.46±0.61 in subsoils at Yoboa and Mabarizinga respectively; the highest soil organic matter content 1.8±0.34% and 1.92±0.43% in topsoil 0.89±0.16% and 1.13±0.19% in subsoils; as well as the highest P content in both available (0.09±0.04% and 0.03±0.04% for topsoils) and total forms (1.19±0.26% and 0.9±0.3% also on topsoils). These values though very low in absolute terms, are not much different from those of other tropical teak-growing countries. Management strategies intended to preserve and improve the present status, particularly the protection of top soil horizons against mainly water erosion, would be able to boost the site productivity.
10

Parametrização do modelo 3-PG para teca (Tectona grandis L.f.) e dos sistemas FERTI-UFV e NUTRI-UFV para subsidiar o seu manejo nutricional / Parameterization of 3-PG model for teak (Tectona grandis L.f.) and of FERTI-UFV and NUTRI-UFV systems to subsidize its nutritional management

Pontes, Mônica da Silva 26 July 2011 (has links)
Made available in DSpace on 2015-03-26T13:53:22Z (GMT). No. of bitstreams: 1 texto completo.pdf: 2966615 bytes, checksum: 848fbb649e8313e67b186309716c1ab9 (MD5) Previous issue date: 2011-07-26 / Teak (Tectona grandis L.f.) is a tree species original from southwest Asia that have adapted well to the Brazilian climatic conditions, especially in the MatoGrosso state. The area planted with teak in Brazil is rising due to its high quality wood and high price at the international market. The productive potential of teak stands can be obtained through modeling and constitutes an input variable to fertilizer recommendation systems based in the nutritional balance (e.g. FERTI-UFV TECA). Recommendations from these systems can be refined by monitoring the nutritional status of the stands based on the leaf nutrient status through NUTRI-UFV TECA. The objectives of this work were: a) parameterize and calibrate 3-PG model for teak stands in the mid-south region of Mato Grosso state; b) evaluate the universality of 3-PG parameterization as function of the forest sites; c) enable 3-PG to estimate teak stands productivity in sites managed by thinning; d) improve FERTI-UFV TECA (Plant submodel) and NUTRI-UFV TECA systems for fertilizer and lime recommendations and nutritional monitoring of teak stands in the Mato Grosso state. This work was carried out in the Santo Antônio do Leverger region MT, in commercial teak stands owned by the Vale do Araguaia Company. The teak stands were sampled at different stages in their cycles (3, 4, 5, 6, 7, 8, and 11 years). Within each sampled stand three trees were cut, measured in terms of DBH and height and separated in its omponents leaves ran hes and trunk . The trees were lassified a ording to their D H as inferior x s mean x s x x s and superior x s and had the on entrations of a g, S, Zn, Fe, Mn, Cu, and B determined for each component. In order to parameterize 3-PG, allometric equations were adjusted to describe biomass production as function of DBH. The diametric distribution model (DDM) employed used the Weibull probability density function adjusted y the maximum likelihood method. β e γ parameters of this function were adjusted for each plot and age, and then correlated with site characteristics. In order to parameterize FERTI-UFV TECA nutrient status of each component was used to estimate the biological utilization coefficient (BUC). For NUTRI-UFV TECA standard nutrient levels (Kenworthy standards) and dual ratios among nutrients (DRIS standards) were estimated based on leaf analysis from 10 locations in Mato Grosso state, comprising teak stands from 1 up to 11 years. Those standards were separated in 2 classes: I) comprising trees up to 5 years old, and II) trees older than 5 years old, with the reference population been constituted by trees growing above than the average. After the parameterization NUTRI-UFV TECA was used to evaluate the nutritional status of the teak stands in Santo Antônio do Leverger. 3-PG returned good estimates for stem (trunk + branches), DBH, height, leaf biomass, and wood volume. With the coupling of DDM it was possible to distribute stem biomass and basal area by 3-PG in diametric classes. The growing and productivity estimates obtained in this present work differed from those by Behling (2009), indicating that 3-PG parameterizations are not universal for teak. Nutrient concentrations varied as a function of the increase in diameter and this variation was different among the compartments. As BUC is the inverse of nutrient concentration, it also varied as a function of DBH. These BUC values and the potential productivity estimated by 3-PG were used to estimate the nutritional demand. In the NUTRI-UFV TECA system general standards differed statistically from age class stratified standards. The coupling of 3-PG and DDM improved the productivity estimates in thinned stands. However, it should be parameterized and calibrated for each region. The models obtained for the BUC values as a function of the age are useful to improve FERTI-UFV TECA system. The foliar nutrient concentration standards and the dual nutrient ratios obtained in this work are useful to improve NUTRI-UFV TECA system, recommending the use of specific standards for each class of age. / A teca (Tectona grandis L.f.) é originária do sudoeste asiático, sendo cultivada no Mato Grosso com sucesso, visando à obtenção de madeira para serraria de ótima qualidade e de elevado valor no mercado internacional. O potencial produtivo de povoamentos de teca pode ser obtido por meio de modelagem baseada em processos e constitui-se em variável de entrada para sistema de recomendação de adubação baseado em balanço nutricional como, por exemplo, o FERTI-UFV TECA. As recomendações assim obtidas podem ser refinadas mediante o monitoramento do estado nutricional com base em análise de tecido foliar pelo uso do NUTRI-UFV TECA. Os objetivos deste trabalho foram: a) parametrizar e calibrar o modelo 3-PG para povoamentos de teca na região Centro-Sul do Mato Grosso; b) Avaliar o grau de universalidade das parametrizações do 3-PG em função do sítio florestal; c) Habilitar o 3-PG para estimar a produtividade, em povoamento de teca, manejados com desbaste; d) Aprimorar os sistemas FERTI-UFV TECA (submodelo Planta) e NUTRI-UFV TECA para a recomendação de fertilização e o monitoramento nutricional dessa cultura no Estado de Mato Grosso. Para tanto, o trabalho foi conduzido na região de Sto. Antônio do Leverger MT, em plantios seminais pertencentes a empresa Companhia do Vale do Araguaia. Para povoamentos de cada idade avaliada (3, 4, 5, 6, 7, 8 e 11 anos) foram abatidas três árvores, classificadas, de acordo com DAP, em árvore inferior (árvore menor que a média menos uma unidade do desvio padrão), árvore média, e árvore superior (maior que a media mais uma unidade do desvio padrão). Essas árvores foram mensuradas quanto ao dap e altura, e separadas em seus componentes (folhas, galhos e tronco). Foram determinados os teores de N, P, K, Ca, Mg, S, Zn, Fe, Mn, Cu e B nos componentes das árvores pelos métodos rotineiros e a área foliar específica. Para a parametrização do 3-PG, foram ajustadas equações alométricas para descrever a produção de biomassa em função do dap. O modelo de distribuição diamétrica (MDD) empregado utilizou a função densidade de probabilidade de Weibull ajustada pelo método da máxima verossimilhança. Os parâmetros β e γ desta função foram ajustados para cada parcela em cada idade, e correlacionados com características do povoamento. Para a parametrização do FERTI-UFV TECA os teores dos nutrientes nos componentes da parte aérea foram utilizados para calcular as respectivas eficiências nutricionais (CUB), e para o NUTRI-UFV TECA foram obtidos as normas de teores (normas Kenworthy) e relações duais entre os teores (normas DRIS) com base nos resultados de análises foliares de teca em 10 municípios do Estado do Mato Grosso abrangendo, em conjunto, plantios de 1 a 11 anos. As normas obtidas foram estratificadas em classe I = árvores de até cinco anos e classe II = árvores com mais de cinco anos, sendo a população de referência, para cada classe, constituída das árvores que apresentaram crescimento maior que a média. O sistema NUTRI-UFV TECA após parametrizado foi utilizado para avaliar o estado nutricional de povoamentos em Sto. Antônio do Leverger. O 3-PG proporcionou boas estimativas para biomassa de stem (tronco + galhos), dap, altura, biomassa de folha e volume de lenho. Com o ajuste dos MDD, foi possível distribuir a biomassa de stem e a área basal estimada pelo 3-PG nas diferentes classes diamétricas e a partir daí foi simulado desbaste pela remoção de árvores das menores classes diamétricas. As estimativas de crescimento e produção obtidas neste trabalho diferem das estimativas obtidas pela parametrização desenvolvida por Behling, 2009, indicando a não universalidade das parametrizações do 3-PG para teca. Os teores de nutrientes variaram em função do crescimento em diâmetro, e essa variação foi dependente do compartimento da planta. Logo os valores de CUB, que é o inverso do teor, também variaram em função do dap. A produtividade potencial obtida com o modelo 3-PG, e os valores de CUB foram utilizados para estimar a demanda nutricional. No sistema NUTRI-UFV TECA as normas gerais diferiram estatisticamente das normas estratificadas por classe de idade. O modelo 3-PG adicionado do MDD proporcionou melhores estimativas de produtividade em povoamentos manejos com desbastes, devendo, contudo, ser parametrizado e calibrado para cada região de plantio da cultura. Os modelos obtidos para os valores de CUB em função da idade são úteis para aprimorar o sistema FERTI-UFV TECA. As normas de teores e relações entre teores foliares geradas neste trabalho são úteis ao aprimoramento do sistema NUTRI-UFV TECA, recomendando-se o uso de normas específicas por classe de idade.

Page generated in 0.0262 seconds