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 20 of 31 for “"N deposition"”.
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EFFECTS OF NITROGEN DEPOSITION ON BOREAL BOGS: A THREE YEAR NITROGEN FERTILIZATION AND TRACER EXPERIMENT
… receiving nutrients only via atmospheric deposition. Increased nutrient deposition, particularly N will almost certainly change the microbiology, biogeochemistry, and C and nutrient balances in bogs. Both primary production and decomposition can be affected, but the net effects of N …
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Atmospheric deposition of combined nitrogen in the Cape Metropolitan Area: a threat to a species rich ecosystem?
… used in order to gauge levels of atmospheric N deposition to the natural vegetation of the Cape Metropolitan Area (CMA). In the first approach, bulk collectors were constructed and set up at five sites around the CMA in order to trap atmospheric deposition for chemical analysis. In the second …
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Environmental change impacts on carbon and nitrogen dynamics in soils and vegetation: from global synthesis to local case studies
… at a mesic grassland; (4) bulk (wet and dry) N deposition in response to proximity to the road in a topographically complex, subalpine forest. Soil organic matter stores carbon (C) and N and thus helps to control climate and provide energy and nutrients for ecosystem function. Thus, …
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Impacts of Best Management Practices on Nitrogen Discharge From a Virginia Coastal Plain Watershed
… N application. The role of atmospheric N (atm-N) deposition (dry+wet) in masking the effects of BMPs on watershed N loading was also investigated. Nitrogen retention and discharge from the forest areas in the NC watershed were simulated using the 5-year water and N input and output data from …
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Development of soil lead and tree-ring methods for characterizing atmospheric deposition gradients and subsequent tree growth responses
Atmospheric deposition of pollutants and nutrients can have a range of effects on aquatic and terrestrial ecosystems. Despite its ecological importance, it remains a challenge to model patterns of deposition across complex terrain and also to assess how forest ecosystems are reacting to chronic …
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A nitrogen budget for the Cape Metropolitan area : is nitrogen enrichment occurring in the soils of remnant patches of lowland fynbos?
… into the atmosphere. The maximum potential N deposition is 184 kg N ha⁻¹ yr⁻¹ for the lowlands. Air quality in an industrial area, Goodwood, has revealed that a large proportion of the emissions remain in the air and have the potential to deposit 33 kg N ha⁻¹ yr⁻¹. Atmospheric N deposited on …
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Examining the Role of Climate, Carbon and Nitrogen Interactions in the Terrestrial Biosphere
… including atmospheric CO2 concentrations, N deposition, climate and land use. This study shows (i) The terrestrial C sink from CO2 fertilization effect is reduced due to the limitation of N (by 0.53GtC/yr in the 1990s), (ii) the positive feedback between climate warming and terrestrial C …
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Consequences of nitrogen fertilization and soil acidification from acid rain on dissolved carbon and nitrogen stability in the unglaciated Appalachian Mountains
… source. We used a wide, chronic gradient of N deposition (5.5 – 31 kg N ha⁻¹ yr-1) to explore patterns in carbon (C) and N cycling in light of recognized biogeochemical responses to acidic deposition. Specifically, we examined the response of key controls on dissolved C and N stability because …
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Modeling the combined environmental effects on net land carbon flux in the present and future scenarios
… effects (atmospheric CO2, nitrogen (N) deposition, climate change, and LULCC) on NBP and the relative contribution of individual environmental effects in the present decade (2009~2018) and the last decade (2090~2099) of the 21st century by using a global land surface model, Integrated …
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Acidification and eutrophication of forests on sandy soil: effects of forest type and deposition load
… decades, what was found to be related to high depositions of potentially acidifying compounds to the forest floor. Several factors are a stimulus for high atmospheric deposition load in these types of forest ecosystems. (1) Forests are often situated in the vicinity of intensive livestock …
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Interactive effects of hemlock mortality and nitrogen availability on nutrient pools and fluxes in the southern Appalachian Mountains
… mid, high) subjected to increasing atmospheric N deposition where hemlock was declining or absent (as reference), in western North Carolina. Nutrient pools varied substantially with elevation and increasing N availability; total forest floor and mineral soil N increased (p<0.0001, p=0.0017, resp.) …
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Stickstoff-Umsätze in Humusauflagen von Buchen- und Fichtenwäldern im Fichtelgebirge (NO-Bayern) und entlang eines europäischen Nord-Süd-Transekts
… beschreiben, verglichen. Entlang eines Depositions- und klimatischen Transekts von Nordschweden bis Mittelitalien sowie im Fichtelgebirge – also bei ähnlicher Deposition und Klima – wurde die Abhängigkeit der N-Umsätze von atmosphärischem N-Eintrag und klimatischen Verhältnissen …
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The effects of accelerated soil acidification on aggrading temperate deciduous forests: The Fernow Experimental Forest Long Term Soil Productivity (LTSP) Study at 13 years
… near Parsons, WV to determine how ongoing acidic deposition may affect total ecosystem carbon (C) storage, stand level dynamics, and soil and foliar chemistry in a young regrowing temperate deciduous forest. I also assessed the potential for acidic deposition effects to cascade up into higher …
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Hyperspectral Reflectance and Stable Isotopic Nitrogen: Tools to Assess Forest Ecosystem Nitrogen Cycling
… fuel combustion and resulting nitrogen (N) deposition across the landscape have contributed to a near doubling of N inputs to terrestrial ecosystems. With such dramatic changes have come adverse environmental consequences including the acidification of soil and water resources and an …
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Estimates of global sources and sinks of carbon from land cover and land use changes
… wood harvest) while accounting for changes in N deposition, atmospheric CO2 and climate. One of the land use datasets is based on satellite data (SAGE) while the other uses population density maps (HYDE), which allows this study to investigate how global LCLUC data construction can affect model …
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Effects of Acid Deposition and Changing Climate on the Hydrochemistry and Critical Loads of Watersheds in the Adirondack Region of New York
<p>Despite decreases in acidic deposition since the 1970s, the recovery of surface waters from acidification has been limited primarily due to the depletion of exchangeable base cations, net mineralization of organic sulfur and nitrogen and release of previously retained SO42- and NO3-, and …
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Effects of nitrogen and water on growth, photosynthesis, and leaf properties of deciduous tree species with consequences for gypsy moth herbivory
… occur in forests receiving elevated N deposition and variations in rainfall events, they will impact feeding behavior and, thus, defoliation by generalist insect herbivores, like gypsy moth.
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The influence of long-term nitrogen fertilization on symbiosis and metabolism in the legume-rhizobium mutualism
… global changes, such as increased nitrogen (N) deposition. Bacterial mutualists in particular might evolve quickly, thanks to short generation times and the potential for independent evolution of plasmids through recombination and/or horizontal gene transfer (HGT). In a previous work using the …
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Carbon and nitrogen cycling in watersheds of contrasting vegetation types in the Fernow Experimental Forest, West Virginia
Increased anthropogenic deposition of nitrogen (N) and land-use changes associated with planted forests have important implications for sustainable forest management and associated water quality. The purpose of the research for this dissertation was to explore how N deposition will affect the …
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Mechanisms of nutrient limitation and nutrient acquisition in managed and unmanaged forest ecosystems
… can balance harvest losses of P and Ca, and N deposition continues its recent decline, N availability may constrain future productivity. I developed a novel tracer experiment intended to confirm earlier reports of the uptake of organic N compounds in temperate forests, which are richer in …
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