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 9 of 9 for “"grass competition"”.
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Functional divergence between Vachellia and Senegalia could underpin differences in invasiveness and Eltonian niche partitioning in African savannas
… in the presence, and also the absence, of grass competition. While I find evidence of some Grinnellian niche differentiation between Vachellia and Senegalia at the landscape-regional scale, their greater-than-expected co-occurrence in plots suggests they generally partition an Eltonian …
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Another look at the savannah conundrum : evidence of niche segregation and competition avoidance with grasses in establishing trees
… but remarkably different life-forms: trees and grasses. However, despite an apparent competitive advantage grasses do not dominate over trees in these systems and this presents a conundrum: how are savannah trees are able to establish in the face of such strong competition from grasses? As this …
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Studies on the Timing of Application, Soil Activity, and Factors Affecting Soil Activity of Several Selective Grass Herbicides (Sethoxydim, Fluazifop-Butyl, Haloxyfop-Methyl)
Field studies on the management of postemergence grass herbicides were conducted. No reduction in soybean yield occurred as a result of up to 5 weeks of early grass competition. Delayed treatment of sethoxydim (10-15 cm stage) especially when planting early provided the best grass control by …
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Water and available nitrogen as co-determinants of a mesic savanna in Kruger National Park, South Africa
… subtropical vegetation type with a continuous grass cover and discontinuous cover of trees. Rainfall plays an important role in savanna as it triggers many ecosystem processes such as nitrogen mineralization. This rainfall is however extremely variable with cycles of wet and dry years. The …
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Limitations of savanna trees in the highveld grasslands of South Africa
Many grassland areas throughout the world may support a woody biomass if fire is suppressed. It is puzzling that fire-tolerant savanna trees do not grow in these grasslands. The Highveld grasslands of South Africa are one such grassland. Hypotheses including fire, human intervention, grass …
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Grass root gaps : an establishment bottleneck limits trees in savannas and excludes them in South Africa's highveld grasslands
The Highveld grasslands of South Africa are climatically capable of supporting trees, yet no trees occur. The fact that no fire adapted savanna trees occur in these grasslands confounds the suggestion that fires maintain these ecosystems. This study addresses the question of what prevents savanna …
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Ecohydrology of a seasonal cloud forest in Dhofar
… vegetation model is used to investigate tree- grass competition in this arid region. The model simulations elucidate the role of clouds in reducing the available energy for transpiration during the wet season. Without representing this role in the model, the simulated soil water storage by the …
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Overseeding Clovers into Permanent Pastures
… L.) establishment into permanent cool season grass pasture and sod. In the pasture experiment, seedling density was measured two months after sowing and grass, white clover, red clover, and weed biomass were periodically measured during the experiment. Broadcast seeding treatment had 93% more …
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Savanna dynamics under extreme conditions
… coexist. Initially attributed to resource competition, coexistence was considered the stable outcome of a root niche differentiation between trees and grasses. The importance of environmental factors became evident later, when data from moister environments demonstrated that tree cover was …