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The Global ETD Search service is a free service for researchers
to find electronic theses and dissertations. This service is
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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.
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Showing 11 to 15 of 15 (0.052 seconds)| 11 |
Performance of farm trees in farming systems in Mubende district, UgandaKrombholz, Max Lukas 15 October 2018 (has links)
The research of this thesis will focus on the performance of farm forestry trees in Mubende district, Uganda. In order to this, the research will help to fill the existing knowledge gap on the performance of farm forestry trees of east Africa specially Uganda. The conducted tree species are Markhamia lutea, Ficus natalensis, Mangifera indica, Artocarpus heterophyllus, Anitaris toxicaria, Persea americana, Albizia coriaria and Spathodea campanulata. The selection of the trees was mainly driven through the availability of age information. The trees were measured in height, age, DBH, length of commercial stem, diameter at specific height and visual observations e.g. occurrence and stem quality. To compare the performance of the conducted tree species a regression analysis with eight different functions was carried out for each tree species. The results are reproducible Stand- Height-Curves, height curves, DBH curves and curves for the single tree volume. The decision on the best curve was made on their biological plausibility and their statistical calculations. Additionally, the farmers of the trees were interviewed about their tree species for e.g. purposes of the tree, value of the wood and their own impressions on the growth of the tree species. The recommendation for the best applicable function is the Petterson function for the Stand-Height- Curve and the function of Richards for the height-, DBH- and single tree volume curve. Still these functions shouldn’t be used without comparison to other functions, especially because the used functions were developed for tree stand conditions and not specially for agroforestry conditions were the tree growth is in general higher.
Additionally, an upscaling and prediction of the monetary tree values is made on the basis of the single tree volume curves and the interview results. The prediction of the farmers possible income through the cultivation of trees is made for Markhamia lutea, Ficus natalensis, Anitaris toxicaria and Albizia coriaria and assumes that 100 trees are planted on one hectare. Albizia coriaria 3.630 € achieves the highest possible extra income for the farmer followed by Ficus natalensis with 1.300 €, Anitaris toxicaria with 910€ and Markhamia lutea with 880 €.
This thesis gives an example on the performance and possible monetary value of tree species in Mubende district, Uganda.
Further investigation is needed to fill the knowledge gap in the performance of east African tree species and their values completely.
Keywords: performance, tree growth, utilization, Uganda, East-Africa
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Diversity and trophic structure of the soil fauna and its influence on litter decomposition in deciduous forests with increasing tree species diversity / Diversität und trophische Struktur der Bodenfauna und ihr Einfluss auf die Streuzersetzung in Wäldern mit zunehmender BaumartendiversitätWeland, Nadine 30 April 2009 (has links)
No description available.
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Abundance, niche breadth and stress in the centre and at the border of the distribution range. / A macroecological study on abundant and rare tree species. / Häufigkeit, Nischenbreite und Stress im Arealzentrum und am Arealrand. / Eine makroökologische Studie über häufige und seltene Baumarten.Köckemann, Benjamin 23 September 2008 (has links)
No description available.
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Soil Chemical and Microbial Properties in a Mixed Stand of Spruce and Birch in the Ore Mountains (Germany) - A Case StudySchua, Karoline, Wende, Stefan, Wagner, Sven, Feger, Karl-Heinz 27 July 2015 (has links)
A major argument for incorporating deciduous tree species in coniferous forest stands is their role in the amelioration and stabilisation of biogeochemical cycles. Current forest management strategies in central Europe aim to increase the area of mixed stands. In order to formulate statements about the ecological effects of mixtures, studies at the stand level are necessary. In a mixed stand of Norway spruce (Picea abies (L.) Karst.) and silver birch (Betula pendula Roth) in the Ore Mountains (Saxony, Germany), the effects of these two tree species on chemical and microbial parameters in the topsoil were studied at one site in the form of a case study. Samples were taken from the O layer and A horizon in areas of the stand influenced by either birch, spruce or a mixture of birch and spruce. The microbial biomass, basal respiration, metabolic quotient, pH-value and the C and N contents and stocks were analysed in the horizons Of, Oh and A. Significantly higher contents of microbial N were observed in the Of and Oh horizons in the birch and in the spruce-birch strata than in the stratum containing only spruce. The same was found with respect to pH-values in the Of horizon and basal respiration in the Oh horizon. Compared to the spruce stratum, in the birch and spruce-birch strata, significantly lower values were found for the contents of organic C and total N in the A horizon. The findings of the case study indicated that single birch trees have significant effects on the chemical and microbial topsoil properties in spruce-dominated stands. Therefore, the admixture of birch in spruce stands may distinctly affect nutrient cycling and may also be relevant for soil carbon sequestration. Further studies of these functional aspects are recommended.
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Relationships between soil chemical properties and forest structure, productivity and floristic diversity along an altitudinal transect of moist tropical forest in Amazonia, Ecuador. / Beziehungen zwischen bodenchemischen Eigenschaften und Waldstruktur, Produktivität und floristischer Diversität tropischer Regenwälder Amazoniens entlang eines Höhengradienten in Ecuador.Unger, Malte Arne 30 April 2010 (has links)
No description available.
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