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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

Dipterocarp seedling growth and mortality in the understorey : roles of herbivory and drought

Bebber, Daniel Patrick January 2003 (has links)
No description available.
2

Some aspects of the biology of mycorrhizas of the Dipterocarpaceae

See, Lee Su January 1992 (has links)
Little is known of the biology and importance of the ectomycorrhizal symbiosis in the Dipterocarpaceae. This project was undertaken: 1) to follow dynamics of mycorrhizal infection of dipterocarp seedlings at different sites in the forest, to characterise the major fungal associations involved; 2) to follow mycorrhizal infection of dipterocarp seedlings under laboratory conditions with different inoculum sources; 3) to determine whether dipterocarp ectomycorrhizas function in a manner similar to temperature ectomycorrhizas in the uptake of specific nutrients. Twenty-four different ectomycorrhizal types were described from roots of newly germinated seedlings, two to seven month-old seedlings and wildings of <i>Shorea leprosula</i> (Miq.), and approximately 20 year-old <i>S. acuminata</i> Dyer, <i>S. dasyphylla</i> Foxw., <i>S. leprosula</i> and <i>S. parvifolia</i> Dyer trees. Seventeen types were tentatively identified to family level. Vesicular-arbuscular mycorrhizas were not found. In the forest, some 14 day-old <i>S. leprosula</i> seedlings were already ectomycorrhizal but infection could be absent up to seven months after germination. The results implied that hyphal connections were important in early infection of seedlings in the vicinity of parent trees. Mycorrhizal infection of sequentially sampled two to seven month-old seedlings declined over the sampling period at two sites in Gombak, Selangor and one in Ulu Langat, Selangor. Five to six ectomycorrhizal types were dominant on seedlings at each site and a succession of types was observed on seedling roots. At final harvest, increased plant growth was significantly correlated with ectomycorrhizal infection only at one site in Gombak where infection by 'dominant' types exceeded 30%. Non-mycorrhizal seedlings of <i>S. acuminata, S. leprosula, Hopea helferi</i> and <i>H. odorata</i> were able to grow normally in sterile soil under non-competitive situations. Seedlings were able to form ectomycorrhizas even with inoculum present in grassland soils or with inoculum from different host species in the case of <i>H. helferi</i>. Increased phosphorus uptake by ectomycorrhizal seedlings of <i>S. acuminata, S. leprosula</i> and <i>H. odorata</i> was demonstrated.
3

Regeneration ecology of broadleaved trees in Caledonian Forest

Ogilvy, Tanya January 2004 (has links)
This thesis quantifies aspects of shade tolerance in tree seedlings of species native to the Caledonian pinewood ecosystems of Glen Affric (Highland Region, Inverness-shire). Growth, allocation and morphological responses of 15 species to irradiance under simulated forest canopy light were investigated in a nursery-based shade house experiment. The same responses of four of the 15 species (Ilex aquifolium, Alnus glutinosa, Sorbus aucuparia and Betula pubescens) to different developmental stages of Pinus sylvestris woodland were investigated in the field. The spatial and temporal growth responses of naturally regenerating S. aucuparia seedlings to shade and gap microhabitats were also studied. Data from the shade house experiment enabled further detailed exploration of the relationship between relative growth rates (RGR) and irradiance and potential cross-overs of ranks of growth in high and low light conditions.
4

Effects of Soil Fungi on Tree Seedling Establishment in a Southeastern Coastal Plain Forest

West, Lee 11 November 1998 (has links)
Effects of fungi and overstory composition on tree seedling survival and growth were investigated in closed canopy upland forests in the coastal plain of South Carolina. Seedlings of Quercus alba, Cornus florida and Pinus taeda were planted in the understory of two forest types -naturally regenerated hardwood and planted pine. Fungal species composition and biomass were experimentally manipulated with a treatment of the fungicide captan. In contrast with other studies conducted in different systems (sand dune, grassland, and old field), the effects of soil fungi were minor in a closed canopy forest. Only Q. alba showed a significant response to the fungicide (p < 0.05) treatment with increased growth. Overstory composition had no significant effect on growth or survival for any of the species. Both of the commercially desirable species (Q. alba and P. taeda) had reasonable survival ( @ 60%). Both also maintained positive, though modest, growth. This suggests that an advance regeneration pool could be established successfully by artificial regeneration. / Master of Science
5

Morphological tradeoffs of American chesnut (Castanea dentata) and co-occurring hardwoods in varying nutrient and light regimes

Thomas, Dana Jeanette. January 2005 (has links)
Thesis (M.S.)--Miami University, Dept. of Botany, 2005. / Title from first page of PDF document. Document formatted into pages; contains [1], v, 38 p. : ill. Includes bibliographical references (p. 35-38).
6

Morphological Tradeoffs of American Chestnut (Castanea Dentata) and Co-Occurring Hardwoods in Varying Nutrient and Light Regimes

Thomas, Dana J. 19 December 2005 (has links)
No description available.
7

Tree Seedling Establishment Under the Native Shrub, Asimina Triloba

Baumer, Marilyn Cabrini 30 July 2007 (has links)
No description available.
8

Composto de lodo de esgoto como substrato para produção de mudas de arvores nativas e exoticas / Composting of sewage sludge in production of seedlings of native and exotic essences

Padovani, Vera Cristina Ramalho, 1965- 22 December 2006 (has links)
Orientador: Durval de Paula Rodrigues Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-09T10:00:40Z (GMT). No. of bitstreams: 1 Padovani_VeraCristinaRamalho_M.pdf: 5126190 bytes, checksum: 92c46be09d3a5c6b107a74a1fbeab24e (MD5) Previous issue date: 2006 / Resumo: Este trabalho tem como objetivo estudar as características físicas e químicas de misturas de diferentes proporções de composto orgânico de lodo de esgoto com casca de arroz carbonizada e avaliar a viabilidade da utilização desses materiais como meio de crescimento para produção de mudas de essências nativas e exóticas. O experimento foi dividido em três fases nas quais foram realizados diversos ensaios. A primeira fase abrangeu a caracterização do lodo de esgoto, do material estruturante e do substrato comercial utilizado no viveiro através de análises químicas. A segunda fase envolveu a realização do processo de compostagem do lodo de esgoto utilizando-se restos de capim e grama cortados, como agente estruturante . Após a compostagem, o lodo de esgoto passou a receber a denominação de COLE ( composto orgânico de lodo de esgoto ) e foi submetido a nova análise química , microbiológica, parasitológica , além da condutividade elétrica. Posteriormente foi misturado com a casca de arroz carbonizada (CAC) nas proporções de 100/00 a 00/100 de COLE/CAC estabelecendo as misturas ou tratamentos que foram submetidos a análises para determinação das propriedades físicas, como macroporosidade, microporosidade, porosidade total , capacidade de retenção de água, densidade aparente . A terceira fase foi dividida em dois ensaios, sendo o primeiro um teste preliminar que utilizou o composto orgânico de lodo de esgoto para a semeadura e cultivo de uma planta indicadora , o tomate, que forneceu resultados que determinaram os tratamentos (substratos) para a instalação do ensaio final , que teve como objetivo o estudo do efeito do substrato na produção de mudas. O segundo ensaio compreendeu a avaliação da produção de essências nativas e exóticas e foi desenvolvido no viveiro municipal da Faculdade Municipal Professor Franco Montoro/Moji Guaçu, onde foram testadas como substrato as proporções 100/00, 90/10,80/20, 70/30, 60/40 (composto orgânico de lodo de esgoto /casca de arroz carbonizada ) utilizando-se tubetes , os quais foram comparados aos substratos testemunhas Plantmax da Eucatex e esterco de curral curtido utilizado pelo viveiro. Foram avaliados parâmetros relativos ao crescimento das mudas: altura de planta (H); diâmetro de colo (D); relação H/D; produção de matéria seca de parte aérea e raiz; relação matéria seca de raiz/matéria seca de parte aérea , área foliar e qualidade de torrão. Os resultados obtidos quanto à caracterização física, microbiológica e química do composto orgânico de lodo de esgoto ( COLE) , indicam que o material está adequado para ser utilizado como meio de propagação de espécies florestais. As mudas de árvores nativas Ingá, Mirindiba rosa e Coração de negro desenvolvidas em substratos contendo composto orgânico de lodo de esgoto ( COLE) / casca de arroz carbonizada (CAC) nas proporções 90/10 e 80/20, apresentaram resultados satisfatórios quando comparados às testemunhas. A espécie exótica Ipê de jardim apresentou bons resultados de crescimento e desenvolvimento das mudas na proporção 90%COLE /10%CAC . Com relação a caracterização nutricional das mudas de Ingá, observou-se que os tratamentos contendo doses de COLE de 70 a 100% apresentaram maior acúmulo de nutrientes nas folhas. A dose de 100% de COLE apresentou resultados superiores em crescimento da parte aérea das mudas, mas insatisfatórios no desenvolvimento das raízes, dificultando a retirada da muda do tubete e interferindo na qualidade final da muda. Com base nos resultados obtidos, conclui-se que o uso do composto orgânico de lodo de esgoto para produção de mudas em tubetes é bastante promissor desde que ele seja utilizado em composição com outro material estruturante , como por exemplo a casca de arroz carbonizada, a fim de se obterem mudas com melhores qualidades fisiológicas e morfológicas / Abstract: This work has as objective to study the physical and chemical characteristics of mixtures of different ratios of organic mixture of sewage with carbonized rice straw and to evaluate the viability of the use of these materials as medium of growth for production of seedlings of native and exotic essences. The experiment was divided in three phases where diverse assays had been carried through. The first phase enclosed the characterization of the sewage sludge, the structural material, and the used commercial substratum in the fishery, through chemical analyses. The second phase involved the accomplishment of the process of composting of the sewage sludge using itself cut remaining portions of grass and gram, as structural agent. After the composting of the sewage sludge to be called COLE ( organic mixture of sewage sludge) and was subdue the new chemical analyses , chemical of microorganism and electric conductivity. Subsequently the sewage sludge and mixes the carbonized rice straw, had been carried through analyses for determination of the physical properties, as macroporosity, microporosity, total porosity, water retention capacity , apparent density and electric conductivity. The third phase was divided in two assays, having been first a preliminary test that used the organic mixture of sewage sludge for the sowing and culture of an indicating plant, the tomato, that it supplied resulted that they had determined the treatments (substratum) for the installation of the final assay, that had as objective the study of the effect of the substratum in the production of seedlings. As the second assay understood the evaluation of the production of native and exotic essences and was developed in the municipal fishery of the Municipal College Professor Franco Montoro /Mogi Guaçu, where ratios had been tested as substratum, 100/00 90/10,80/20, 70/30, 60/40 (organic mixture of sewage sludge/ carbonized rice straw) using tubetes, which had been compared with substrate witnesses Plantmax of the Eucatex and dung of tanned corral used for the fishery. Relative parameters to the growth of the changes had been evaluated: height of plant (h); collar diameter (d); relation H/D; dry matter production of aerial part and root; ratio between dry matter of root and aerial part; leaf area and quality of aggregation of the substratum. The gotten results how much the physical, microbiological and chemical characterization, of the organic mixture of sewage sludge (COLE), indicates that the material is adjusted to be used as half of propagation of forest species. The changes of native trees Ingá, Mirindiba rosa and Coração de negro in substrata I contend organic mixture of sewage sludge (COLE)/ carbonized rice straw (CAC) in ratios 90/10 and 80/20, had presented resulted satisfactory when comparative the witnesses. The exotic species Ipê de jardim presented good results of growth and development of the seedlings in the ratio 90%COLE /10 %CAC. With regard to nutrition characterization of the seedlings of Ingá, it was observed that the treatments I contend doses of organic mixture of sewage sludge (COLE) of 70 the 100%, had presented greater accumulation of nutrients in leaf. The dose of 100% of organic mixture of sewage sludge (COLE) presented resulted superior in growth of the aerial part of the seedlings, but unsatisfactory in the development of the roots, making it difficult the withdrawal of the dumb one of container and intervening with the final quality of the seedling . On the basis of the gotten results, the use of the organic mixture of sewage sludge for production of seedlings in containers is concluded that, is sufficiently promising since that, the same either used in composition with another structural agent , as for example the carbonized rind of rice, in order to get seedlings with better physiological and morphologic qualities / Mestrado / Agua e Solo / Mestre em Engenharia Agrícola
9

Secondary succession toward woodland - Changes in the herb layer species composition / Secondary succession toward woodland - Changes in the herb layer species composition

DOSTÁLOVÁ, Alena January 2010 (has links)
This dissertation focus on spontaneously developed forests (SDFs) on mesic stands. The present tree layer was described and the possible changes in the tree layer was estimated. Influence of site- and context-dependent factors on the species composition and general character of the herb layer was studied in detail. An experiment was established to study seed and safe-site limitation of nine forest herb species.

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