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 40 for “"net primary productivity"”.
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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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Quantifying Trends In our National Parks: A Landscape Level Analysis of Climate Change and Ecosystem Productivity
… ecosystem health indicators (available water and net primary productivity; NPP) we identified the National Park System units that are rapidly changing with respect to climate and ecosystem productivity. Additionally, we compared the NPS units with the surrounding, protected area centered ecosystem …
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Quantifying Trends In our National Parks: A Landscape Level Analysis of Climate Change and Ecosystem Productivity
… ecosystem health indicators (available water and net primary productivity; NPP) we identified the National Park System units that are rapidly changing with respect to climate and ecosystem productivity. Additionally, we compared the NPS units with the surrounding, protected area centered ecosystem …
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The timing of growing season drought and its effects on above- and belowground production in a mesic grassland
… the response of both above- and belowground net primary production (ANPP & BNPP) to reductions in precipitation in a mesic, tallgrass prairie in NE Kansas. Experimental plots were subjected to one of three drought treatments (25% reductions in the average growing season precipitation [GSP]) …
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Relationships between tree rings and Landsat EVI in the Northeast United States
Changes in the productivity of temperate forests have important implications for atmospheric carbon dioxide (CO2) concentrations, and many efforts have focused on methods to monitor both gross and net primary productivity in temperate forests. Remotely sensed vegetation indices provide spatially …
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Species and functional diversity effects on productivity and nutrient uptake: implications for designing sustainable agricultural systems in the Midwest
… did exhibit the greatest relative aboveground net primary productivity. The perennial species, particularly the C3 species, had higher biomass production and nutrient uptake at the beginning and end of the growing season compared to annual crops. The species stiff goldenrod was one species that …
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Relationships between Forest Productivity and Water Yield Across Virginia's Forests
… often incentivized solely for maximized forest productivity (i.e., increasing biomass or carbon); however, maximizing forest productivity can result in a decline in downstream water resources, highlighting the need for a better understanding of such tradeoffs to inform incentive programs aimed …
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Effects of Air vs. Air+Soil Heating During a Simulated Heat Wave on White Oak (Quercus alba) and Black Oak (Quercus velutina)
… areas of the world. Large-scale reductions in Net Primary Productivity and mortality have been reported during heat waves in forested ecosystems. Unfortunately, our understanding of how abrupt heat-stress affects woody species during heat waves lags behind our knowledge of herbaceous species …
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Genetics by Nutrient Availability Interactions on Short-term Carbon Pools and Fluxes in Young Pinus taeda Plantations
… of this research was to determine how genetics and nutrient availability influence C cycling in intensively managed southern pine forests. This work consisted of a two year field and a complimentary one year greenhouse study each split into above- and below-ground pools and fluxes. Both …
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The effect of timing of growing season drought on flowering of Andropogon gerardii
… ecosystem function, especially aboveground net primary productivity (ANPP), in a variety of ecosystems. The particular precipitation period(s) of greatest importance varies between ecosystems. In tallgrass prairie of the central US, the relative importance of different precipitation periods …
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Testing the Limits of Hyperspectral Airborne Remote Sensing by Mapping Eelgrass in Elkhorn Slough
… Eelgrass covered 10 ha of the Slough and net primary productivity totaled 1 x10<sup>8</sup> g C yr<sup>-1</sup>. These results could not be reproduced with uncalibrated aerial photography (e.g., Google Earth). Atmospherically corrected and calibrated hyperspectral imagery was needed to …
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Carbon cycling in secondary tropical dry forest from species to global scales.
… of biomass. In Chapter 4, I measured aboveground net primary productivity in 18 secondary forest plots in northwestern Costa Rica over three years. I found that large inter-annual differences in precipitation do not significantly affect ANPP and that variation in litterfall and biomass among our …
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Community and ecosystem changes in tallgrass prairie restorations: the effects of population source and diversity
… ecosystem functions including aboveground net primary productivity, total, microbial, and mineralizable soil C, and soil aggregate mean weighted diameter were achieved equally well with either high or low diversity prairie plantings.
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Soybean nitrogen dynamics: Nitrogen fixation, yield, and residue decomposition
… a crucial element for plant growth, often limits net primary productivity of agroecosystems. In agricultural systems it is vital to have proper management of N to secure productivity and environmental sustainability. Soybean [Glycine max (L.) Merr.] is the second most important crop in the US Corn …
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Ecosystem Net Primary Production Responses to Changes in Precipitation Using an Annual Integrated MODIS EVI
In this study, the relationship of above-ground net primary productivity (ANPP) with precipitation using the enhanced vegetation index (EVI) from satellite data as surrogate for ANPP was assessed. To use EVI as a proxy for ANPP we extracted the satellite data from areas with uniform vegetation in a …
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Soybean's Future: Photosynthesis, Sucrose Transport, Dry Mass Accumulation and Yield in a Changing Atmosphere
… Growth in elevated [O3] decreased above-ground net primary productivity (ANNP, ∼11%) and reproductive production (14%) without significantly altering mass partitioning. Conversely, growth in elevated [CO2] over 3 years increased ANPP (17--18%) and yield (15%). Although ANPP and yield …
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Exploring the Impact of Climate and Productivity on Soil Carbon Across the Native Range of Loblolly Pine
… in mean annual temperature (MAT) and annual net primary productivity (NPP) for the native range of loblolly pine (Pinus taeda L). A Monte Carlo method was used to calibrate a large ensemble of model parameters using observational data from loblolly pine stands. Spatial projections of carbon …
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Study on Regional Responses of Pan-Arctic Terrestrial Ecosystems to Recent Climate Variability Using Satellite Remote Sensing
… radiation inputs to assess annual terrestrial net primary productivity (NPP) for the pan-Arctic basin and Alaska from 1983 to 2005. I developed a satellite remote sensing based evapotranspiration (ET) algorithm using GIMMS NDVI with the above meteorology inputs to assess spatial patterns and …
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Study on Regional Responses of Pan-Arctic Terrestrial Ecosystems to Recent Climate Variability Using Satellite Remote Sensing
… radiation inputs to assess annual terrestrial net primary productivity (NPP) for the pan-Arctic basin and Alaska from 1983 to 2005. I developed a satellite remote sensing based evapotranspiration (ET) algorithm using GIMMS NDVI with the above meteorology inputs to assess spatial patterns and …
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