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Full-Text Articles in Physical Sciences and Mathematics
Carbon And Nitrogen Dynamics Of A Lagoon Salt Marsh In Davenport, California, Mark D. Gormley
Carbon And Nitrogen Dynamics Of A Lagoon Salt Marsh In Davenport, California, Mark D. Gormley
Dissertations, Theses, and Capstone Projects
Wetlands are complex environments that play a critical role in regulating the global biogeochemical cycle of carbon (C) and nitrogen (N). Wetlands are critical contributors to global climate change and atmospheric chemistry since they store as much as 33% of the world’s soil organic carbon (SOC), release more than 20% of the atmospheric methane (CH4), and produce nitrous oxide (N2O), an extremely potent greenhouse gas (GHG). Despite the enormous radiative forcing potential of carbon dioxide (CO2), CH4 and N2O derived from wetlands, uncertainties over the rates of C sequestration and GHG …
Ice And Guano Deposits In El Malpais Lava Tubes: Potential Paleoclimate Archives For The Southwest United States, Dylan S. Parmenter
Ice And Guano Deposits In El Malpais Lava Tubes: Potential Paleoclimate Archives For The Southwest United States, Dylan S. Parmenter
USF Tampa Graduate Theses and Dissertations
Three ice cores and one guano core were obtained from lava tubes in El Malpais National Monument, New Mexico, in the Southwest United States. A large hiatus in the Bat Cave guano record, resulting from mining activities in the early 1900's, left us with only ~50 years of data (from AD 1955-2006) to use in analysis. 13C values in guano (-18 to -11.6‰) primarily fall within the range of C4 plants, and likely indicate a tendency of Tadarida brasiliensis to feed on insects over grasslands to the North or South of the park. Variations in 13C values for this period …
A Bat-Guano-Derived Δ15N And Δ13C Record Of Paleoenvironmental Change: Zidită Cave, Romania, Daniel Martin Cleary
A Bat-Guano-Derived Δ15N And Δ13C Record Of Paleoenvironmental Change: Zidită Cave, Romania, Daniel Martin Cleary
USF Tampa Graduate Theses and Dissertations
Because nitrogen isotopes are fractionated along the soil-plant-insect-bat-guano pathway, it may be possible to reconstruct environmental and climatic changes reflected in the nitrogen isotopic composition of guano. A 1.5-m core of bat guano from Zidită Cave (western Romania) provides a record of climatic and anthropogenic influence on the regional nitrogen cycle and paleoenvironmental controls on nitrogen transforming processes. Increasing and decreasing trends of nitrogen isotopic composition (δ15N values) correspond well with changes in the influence of farming practices, deforestation, and forest expansion. These influences likely had a significant effect on the openness of the nitrogen cycle, resulting in …