Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 17 of 17 for “"tropical ecosystems"”.
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Role of Dissolved Organic Nitrogen in the Soil Nitrogen Cycle of Forest Ecosystems
… be a crucial part of the soil N cycle in forest ecosystems. Despite this, information on its dynamics, sources and fate is still lacking. Especially data from (sub)tropical forest ecosystems are scarce. Therefore, this study investigated (i) the magnitude and drivers of DON fluxes in a …
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The Role That Asexual Reproduction Plays in the Regeneration of Tropical Piper Shrubs: Habitat Differences and Genetic Consequences
… but little explored characteristic of many tropical plants with a variety of life-histories and habitat requirements. My dissertation research examined the ecological correlates and population genetic consequences of asexual reproductive success in five co-occurring Piper species using a …
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Iron-Carbon Associations In Tropical Soils Of The Luquillo Critical Zone
… behavior of soil carbon (C) in humid tropical ecosystems derives from an incomplete understanding of soil C stabilization processes. Long-term soil C stability is traditionally attributed to organomineral interactions, however, the 2:1 phyllosilicate clays often associated with …
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Experimental litterfall manipulation effects on soil bacterial community structure and soil carbon cycling in a wet tropical forest
… plant-derived carbon (C) inputs to terrestrial ecosystems via changes in litterfall and plant net primary production (NPP). However, the effects of shifting detrital C inputs on belowground microbial community function, C cycling and fluxes remain largely unknown, especially in tropical forest …
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Experimental litterfall manipulation effects on soil bacterial community structure and soil carbon cycling in a wet tropical forest
… plant-derived carbon (C) inputs to terrestrial ecosystems via changes in litterfall and plant net primary production (NPP). However, the effects of shifting detrital C inputs on belowground microbial community function, C cycling and fluxes remain largely unknown, especially in tropical forest …
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Shifts in Myxomycete Community Structure in Selected Microhabitats Across Nutrient Treatments in a Lowland Tropical Forest of Panama
… is well established. Given the extent to which tropical ecosystems influence global nutrient fluxes, along with the ecologically significant role that myxomycetes play in these processes, there is a pressing need to learn more about this understudied community.</p> <p>This dissertation comprises …
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Microwave remote sensing of water in the soil - plant system
… amounts of measurement noise. In several dry tropical ecosystems, the resulting VOD dataset is shown to have opposite temporal behavior to coincident cross-polarized backscattering coefficients, an active microwave indicator of vegetation water content and scattering. This possibly shows dry …
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The Relationship between Carbon Emissions, Land Use Change and the Oil Palm Industry within Southeast Asia
<p>Tropical forests store the largest amount of carbon globally by sequestering up to 2.7 Gt of carbon every year in soils and vegetation. Deforestation and the conversion of tropical peatland soil have contributed to global anthropogenic carbon dioxide emissions, as well as significantly hindering …
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The double life of an insect pathogen: Metarhizium as a plant symbiont and its genetic diversity in coffee agroecosystems
… plant rhizosphere are very sparse, especially in tropical ecosystems. Also, considering the ability to form mutualistic association with plants, no Metarhizium’s specific molecular method is available to detect and quantify association in plant root systems. Given this, in this thesis we focused …
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Systematic conservation planning in Thailand.
Thailand supports a variety of tropical ecosystems and biodiversity. The country has approximately 12,050 species of plants, which account for 8% of estimated plant species found globally. However, the forest cover of Thailand is under threats: habitat degradation, illegal logging, shifting …
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Detection of Mortality in Tropical Forests Using Remote Sensing: From Treefall Gaps to Large Disturbances
… and intensity of natural disturbances in tropical forests continually re-shape forest structure. At small scale, branch or tree-falls gaps and subsequent recovery are important mechanisms for carbon cycling. At landscape scale, large disturbances (blow-downs) may also play a role on the …
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Remote Sensing of Fire, Flooding, and White Sand Ecosystems in the Amazon
… relatively undisturbed savanna-like `campina' ecosystems. I reviewed the literature on campinas and discussed their variation and their significance for beta diversity. As one of two case studies, I assessed spatio-temporal patterns of disturbance (fire and blowdowns), and vegetation change …
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Multiscale Anthropogenic Impacts on Stream Condition and Fish Assemblages in Amazonian Landscapes.
… are resulting in pervasive changes to tropical ecosystems around the globe. While evidence from terrestrial systems demonstrates the severity of these disturbances for biodiversity conservation and provision of ecosystem services, the consequences for freshwater ecosystems remain poorly …
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A Genomics Approach to Conservation, Systematics, and Phylogeography to Understand Two Lineages of Lamiales
… which are Barleria (ca. 300 spp., primarily paleotropical), and the pantropical Lepidagathis (ca. 100 spp.). Many species in this group are important in tropical ecosystems and support a wide range of pollinators. Barlerieae present several taxonomic problems, and some species have intriguing …
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Ectomycorrhizal associations in tropical montane forest: insights into their influence on nutrient cycling and functional responses to soil fertility
… of individuals. Monodominance is unexpected in tropical forest because the accumulation of host-specific pathogens is thought to limit the local abundance of individual species. Although rare, monodominant forests have now been recognized in all major tropical regions and include a wide …
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ASSESSING AND IMPROVING BIODIVERSITY OUTCOMES FOR TROPICAL FOREST RESTORATION
… as a key strategy to stem biodiversity declines. Tropical forests, which both house 80% of global biodiversity and account for 90% of deforestation from 2000-2018, are a particular focus of international initiatives like the Bonn Challenge and the UN Decade on Ecosystem Restoration (2021-2030). …
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Effects of fragmentation and invasion on ant communities
… characteristics are especially problematic in tropical ecosystems where nutrient-poor soils do not easily meet the agricultural demands of growing human populations. A consequence of replacing tropical forests with agriculture is the creation of landscapes consisting of fragments of natural …