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 14 of 14 for “"Gross 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 …
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Remote sensing of croplands, crop productivity, and water use efficiency with a focus on smallholder systems in southern Africa
… mapping of croplands, estimation of crop productivity, and monitoring of production trends are required. Accommodating the dynamic, seasonal nature of farming systems in mapping and productivity models, and production trend monitoring methods, may enhance their accuracy. Further, these …
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Remote sensing of croplands, crop productivity, and water use efficiency with a focus on smallholder systems in southern Africa
… mapping of croplands, estimation of crop productivity, and monitoring of production trends are required. Accommodating the dynamic, seasonal nature of farming systems in mapping and productivity models, and production trend monitoring methods, may enhance their accuracy. Further, these …
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Validation and application of the MERIS Terrestrial Chlorophyll Index.
… product to monitor phenology, stress and productivity. The MTCI needs full validation if it is to be embraced by the user community who require precise and consistent, spatial and temporal comparisons of vegetation condition. This research details experimental investigations into variables …
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Design and evaluation of distributed spacecraft missions for multi-angular Earth observation
… other and monoliths, in terms of BRDF, albedo, gross primary productivity and total outgoing radiation. Performance is benchmarked with respect to data from previous airborne campaigns (NASA CAR), tower measurements (AMSPEC II) and ideal values from radiative transfer or climate models (UMGLO, …
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Ecosystem-atmosphere exchange of carbon dioxide and water vapour in typical East-Asian croplands
… the light response function indicates that the primary cause of seasonal change in gross primary productivity was the change in leaf area index during the whole growing season under the summer monsoonal condition. Thus, a site-specific time window approach could significantly improve the model …
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Understanding Carbon Uptake Using Multi-Scale Novel Remote Sensing Techniques
… scale, solar-induced fluorescence (SIF) captures gross primary productivity (GPP) phenology more accurately than the normalized difference vegetation index (NDVI) and vegetation optical depth (VOD). In dryland regions, integrating near-infrared reflectance of terrestrial vegetation (NIRv), SIF and …
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Combining remotely sensed estimates of structure and function to improve quantification of forest productivity
Gross primary productivity (GPP) describes the total photosynthesis (i.e., carbon fixation) for an ecosystem and is an important component of the global land carbon budget. Accurate measurements of forest carbon sequestration are crucial, as climate, soils, and management practices influence carbon …
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Quantifying terrestrial ecosystem carbon dynamics with mechanistically-based biogeochemistry models and in situ and remotely sensed data
… of net ecosystem exchange (NEE) and the derived gross primary productivity (GPP) to the conterminous United States. We found that atmospheric CO 2effect on GPP/NEE exhibited a great spatial and seasonal variability. Further analysis suggested that air temperature played an important role in …
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Impacts of Elevated Carbon Dioxide and Tropospheric Ozone on the Growth and Productivity of Trees
… of the impact of these gases on tree growth and productivity. Free-Air Concentration Enrichment (FACE) technology was employed at PopFACE to fumigate three fast growing Populus species to elevated [CO2] of 550 under open-air conditions from planting through canopy closure. Extensive measurements …
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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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Assessment of grassland ecosystem functioning: Carbon dioxide exchange and the dynamics of carbon and nutrient pools in temperate and Mediterranean grasslands
… (NEE) and respiration was nearly zero. The gross primary productivity (GPP) at the cut site was higher than at the uncut site due to vegetation recovery at the former and senescing leaves at the latter site. Results from the artificially created grassland showed that drought altered the …
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Evaluation of New Zealand estuarine water properties using remote sensing
… surrounding landscape, light availability and primary productivity can be strongly restricted, which may trigger rapid ecological change over time and cause substantial loss of coastal flora and fauna. This thesis explores the use of Sentinel-2 remote sensing imagery to monitor water properties …
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From Hyperspectral Indices to Global Fluorescence: PACE Vegetation Indices as Predictors of Terrestrial Photosynthesis
… it a valuable tool for assessing terrestrial productivity. However, the practical application of satellite-derived SIF is hindered by spatial resolution limitations and data gaps. The NASA Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission presents an opportunity to overcome these …