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 249 for “"primary productivity"”.
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Improving estimation of gross primary productivity of terrestrial ecosystems
… My doctoral study improves estimation of gross primary productivity (GPP) through two aspects: first, my study improved the detection of vegetation phenology by distinguishing MODIS contaminated observations and contamination-free observations, and secondly, I inverted the fraction of absorbed …
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Physical Controls on Low and Mid-Latitude Marine Primary Productivity
… is generally expected to inhibit marine primary productivity at low and mid latitudes, based on the supposition that increased water column stability will decrease vertical mixing and consequently the upward entrainment of deep nutrients into the euphotic zone. Herein, we examine the …
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Primary productivity and its variability in the Atlantic Southern ocean
… of the meridional characteristics of primary productivity in the Atlantic Southern Ocean during austral summer 2008.
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The photophysiology and primary productivity of phytoplankton within the deep chlorophyll maximum
… This study explores the significance of primary production (PP) within the DCM and provides a detailed investigation into the mechanisms of phytoplankton adaptation to this tidally dynamic and dimly-lit environment. Comparison is drawn to the DCM in a range of hydrographic regimes in the …
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Benthic and Planktonic Microalgal Community Structure and Primary Productivity in Lower Chesapeake Bay
… quantification of cell abundance, biomass, and primary production. Whole water samples and sediment cores were collected at eight sites throughout lower Chesapeake Bay for phytoplankton and microphytobenthic community analysis over a two-year period. Over the span of the study, a total of 142 …
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Primary Productivity Distributions Along the River-Dominated Shoreline of the Bay of St. Louis, MS Estuary
<p>Potential primary production was measured for six consecutive months (July 2010 to December 201 0) at selected stations along the shoreline of the Bay of Saint Louis (BSL) estuary. Monthly surface and a series of subsurface (0.5 m) samples were taken to observe the temporal (monthly and …
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Factors Influencing the Spatial and Temporal Distrubtion of Primary Productivity and Community Respiration in the Mississippi Coastal Estuarine Region
… the spatial and temporal distribution of net primary productivity (NetPP) and respiration (RESP) in relation to the biogeochemical, optical, and hydrographic variability in the Mississippi Sound and Mississippi Bight over the course of one year. Surface in-situ measurements of NetPP and RESP …
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Investigation of primary productivity along the Atlantic Meridional Transect (50°N to 33°S) through fast repetition rate fluorometry
Phytoplankton physiology and primary productivity at basin scales were determined using in situ data from fast repetition rate (FRR) fluorometry. Samples were collected along the Atlantic Meridional Transect cruise 11 (AMTll, September-October 2000), between 50°N and 33°S in the Atlantic Ocean. …
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Investigation of the distribution, structure, composition, development and primary productivity of blue-green algal mat communities in an Antarctic lake
… associated meltstreams. The contribution of mat primary productivity to the total lake metabolism was estimated. Thin lemon-yellow mats of high algal diversity dominated by diatoms and filamentous blue-green algae comprised the stream mat community. These mats inoculated shallow areas in the lake …
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Heavy metal concentrations, primary productivity, chlorophyll-a levels, and the autotrophic indices of stream periphyton subjected to wood preservation waste
… from the source of contamination. The periphyton primary productivity, chlorophyll-a content, and autotrophic index were also determined. Water samples were analyzed for the three metals; arsenic, chromium, and copper. The highest mean periphyton arsenic and chromium concentration occurred at the …
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Links between the Seychelles-Chagos thermocline ridge and large scale climate modes and primary productivity; and the annual cycle of chlorophyll-a
The Seychelles-Chagos Thermocline Ridge (SCTR) is a region of upwelling present at 55°E- 90°E and 5°S-12°S in the southwest tropical Indian Ocean. It is a region of strong ocean-atmosphere interactions due to the high variability of the thermocline depth caused by the local Ekman pumping. …
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Seasons in the Stream: River Ecosystem Phenology in a Changing Climate
<p>Patterns of primary productivity are primarily dictated by seasonal factors like light availability and temperature. In small rivers, primary productivity often peaks opposite that of terrestrial ecosystems, where overhanging canopies shade the river channel impeding light reaching the water …
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Nutrient and Carbon Dynamics in the Chesapeake Bay Outflow Plume and Their Effect on the Coastal Ocean Environment
… the characterization of nutrient concentrations, primary productivity rates, and the uptake of nitrogen using stable isotopes, I identified three different plume types that differentially provided nutrients and created conditions either suitable or unsuitable for primary productivity in the …
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Limnological investigations of a natural, subalpine lake in the early stages of eutrophication: Mountain Lake, Giles County, Virginia
… have occurred over the past decade, although primary productivity, cell densities, and chlorophyll a values indicate no consistent trends. Hypolimnetic oxygen deficits, however, have continued to increase over time, and in October 1994 the first measure of anoxic deep water was observed. …
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Aufwuchs communities of lotic systems: nontaxonomic structure and function
… triphosphate and chlorophyll a) and function (primary productivity and assimilatory sulfate reduction). In eleven experiments, individual streams were treated with potential"enrichments" of sucrose, dextrose, ammonium nitrate, potassium dihydrogen phosphate, and toxicants including copper …
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Landscape scale measurement and monitoring of biodiversity in the Australian rangelands
… scales of the Australian rangelands is the Productivity Theory, which reasons that the greater the amount and duration of primary productivity the greater the capacity to generate and support high biodiversity. The most significant pressure on biodiversity in the study area is …
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Temperature regulation and energetics of the guanaco (Lama guanicoe)
… by low precipitation, high winds and low primary productivity.
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Phytoplankton productivity and Milankovitch Cycles in the Cenomanian-Turonian Bridge Creek member of the Greenhorn Formation in southeastern Colorado
… have been caused by a combination of fluctuating primary productivity and humid/arid climate cycles. Species richness and evenness indices for palynomorph assemblages from 24 Bridge Creek beds were statistically analyzed using Analysis of Variance. The results indicate that assemblages for the …
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