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Full-Text Articles in Physical Sciences and Mathematics
Spatiotemporal Variability Of Soil Water Δ18o And Δ2h Reveals Hydrological Processes In Two Floodplain Soils, Amanda Ceming-Barbato
Spatiotemporal Variability Of Soil Water Δ18o And Δ2h Reveals Hydrological Processes In Two Floodplain Soils, Amanda Ceming-Barbato
LSU Master's Theses
The movement of water through soil is preferential and heterogeneous. Subsurface interactions between mobile flows and the soil matrix are not uniform and are therefore difficult to predict through time and space. The use of stable isotopes of hydrogen (2H) and oxygen (18O) as conservative tracers of water movement is improving understanding of soil hydrological processes, yet field-scale observations of isotopic variability remain scarce despite implications for identifying dominant hydrologic processes. We sampled two adjacent soils at a ridge-swale topography floodplain forest to determine soil water isotopic variability at a 20 cm depth resolution in soils …
A Study Of Stable Isotopes In Snow On Mt. Hood, Oregon, Maya Felix
A Study Of Stable Isotopes In Snow On Mt. Hood, Oregon, Maya Felix
University Honors Theses
Over the 2020-2021 Winter, event-based and end-of-season snow samples were collected on Mt. Hood near Government Camp, OR and analyzed for their stable isotopic compositions of 18O and 2H. It was found that surficial snow collected through the winter had higher variation in isotopic values than samples from a snow pit collected in spring. This suggests homogenization occurred in the snowpack over the season from snow metamorphism, sublimation, and/or melting. Homogenization of the snowpack will likely become more pronounced as temperatures increase and rain falls more often than snow due to climate change. Research that utilizes the snowpack …
Mosquito Distribution And Stoichiometric Analysis Between Open And Closed Canopies In New Orleans Cemeteries, Rachel Rogers
Mosquito Distribution And Stoichiometric Analysis Between Open And Closed Canopies In New Orleans Cemeteries, Rachel Rogers
LSU Master's Theses
Cemetery vases represent an important container habitat for mosquito larvae. Some species, like, Aedes albopictus and Aedes aegypti, prefer container habitats, whereas others, like Culex quinquefasciatus, will opportunistically use containers. In New Orleans, these three medically important vector species (Ae. albopictus Ae. aegypti, and Cx. quinquefasciatus) co-occur, despite a demonstrated competitive advantage of Ae. albopictus to the other two. Here we test the hypothesis that canopy cover from trees could be a mediating factor in driving mosquito assemblages in New Orleans, by influencing food sources, and the microclimate experienced by mosquito larvae. Samples from seven …
Can Stable Isotopes From Tree Rings Improve Our Understanding Of Past Variability In The Southern Annular Mode?, Zachary Grzywacz
Can Stable Isotopes From Tree Rings Improve Our Understanding Of Past Variability In The Southern Annular Mode?, Zachary Grzywacz
Graduate Theses, Dissertations, and Problem Reports
Few annually dated stable isotope records exist across Oceania. In mid- to high-latitude locations in South America, tree-ring stable isotopes provide information about past climate dynamics such as the Southern Annular Mode (SAM). The SAM drives latitudinal shifts in Southern Hemisphere westerly winds, influencing temperature and moisture delivery across the mid- to high-latitudes, including Tasmania. Combinations of paleoclimate proxies from across the Southern Ocean might provide insight into dynamic processes like the SAM that are difficult to measure with a single proxy. Measuring stable carbon and oxygen isotope ratios from tree rings in Tasmania could provide complementary data to contribute …
Diversity And Function Of Algal Biofilms In The Laurentian Great Lakes, Leon R. Katona
Diversity And Function Of Algal Biofilms In The Laurentian Great Lakes, Leon R. Katona
Browse all Theses and Dissertations
Attached algae are ubiquitous components of lake benthic habitats wherever sufficient light reaches submerged surfaces. Attached algae interact with heterotrophic bacteria and fungi to form complex biofilms (“periphyton”) that provide a nutritious food source for consumers and influence biogeochemical cycling by regulating redox potential at the sediment-water interface. Despite their ecological importance, there are limited data on the role of periphyton in the Laurentian Great Lakes. I quantified wave exposure and light availability in rocky nearshore habitats in Lake Erie and Lake Huron. Periphyton biomass and productivity in nearshore Lake Erie was very high while algal biomass and productivity in …
Organic-Input Impacts On Soil Carbon Flux, Storage, And Budget In Conservation Agricultural Soils, Central Washington, Usa, Jessica Hartman
Organic-Input Impacts On Soil Carbon Flux, Storage, And Budget In Conservation Agricultural Soils, Central Washington, Usa, Jessica Hartman
All Master's Theses
The increase in global atmospheric CO2 over the last 200 years has generated an urgent need for strategies for sequestering carbon (C). Soil C, which has been depleted by land use change and agricultural practices, is a prime target for C storage. Land management practices, including no-till, cover cropping and crop rotation, and the application of C amendments such as compost and biochar, are suggested to increase C in the soil. Spoon Full Farm, near Thorp, WA, was a conventional hay farm until 2016, when management practices changed to implement some of these C sequestration strategies. A prior CWU …