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Full-Text Articles in Physical Sciences and Mathematics
Phosphorus Recycling By Profunda Quagga Mussels In Lake Michigan, Caroline Mosley
Phosphorus Recycling By Profunda Quagga Mussels In Lake Michigan, Caroline Mosley
Theses and Dissertations
Quagga mussels (Dreissena rostiformis bugensis) act as ecosystem engineers in the southern basin of Lake Michigan, altering physical habitats and biogeochemical processes. Adapted to cold and oligotrophic conditions, profunda quagga mussels thrive on the soft substrate of deeper depths. At a 55 m site (10,000 mussels m-2) offshore from Milwaukee, WI, profunda mussel biomass (g m-2) was 1/3 of biomass (g m-2) measured at a 10 m comparison site (5,000 mussels m-2). Higher densities but less biomass is due to profunda mussels having less tissue for a given length and the population per m2 comprising of mostly small mussels ( …
Early Triassic Echinoids Of The Western United States: Their Implications For Paleoecology And The Habitable Zone Hypothesis Following The Permo-Triassic Mass Extinction, Jenna Rolle
Theses and Dissertations
Confronted with global climate change and ocean acidification, our collective knowledge of ecosystem response during times of environmental crisis in Earth's ancient past may provide insights towards combating ecological degradation in modern oceans. Early Triassic marine environments were characterized by oceanic warming due in part to elevated levels of atmospheric CO2 and periodic intervals of localized anoxia, resulting in an overall restructuring of faunal dominance, distribution, and biodiversity. Re-assembly of ecological communities during the Early Triassic are largely unknown; however, a previous paleoecological study by Tyler Beatty et al. (2008), suggests that post-extinction recovery length was minimized in shallow …
Impacts Of Spatial, Environmental, And Compositional Differences On Community-Level Flowering Phenology, Isaac William Park
Impacts Of Spatial, Environmental, And Compositional Differences On Community-Level Flowering Phenology, Isaac William Park
Theses and Dissertations
This dissertation investigates three important topics related to flowering phenology throughout the United States. First, this work evaluates the utility of herbarium records for estimating historical variation in community-level flowering phenology, and evaluate the relationship of such estimates to satellite-derived greenup timing at regional scales. This dissertation then reconstructs historical variations in flowering phenology throughout the spring, summer, and autumn across South Carolina for the years 1951 through 2009. These estimates will then be compared to seasonal temperature variations throughout this period. Finally, this dissertation develops novel herbarium-based methods to separate intraspecific phenological variations over space from changes in flowering …
Plankton Trophic Structure Within Lake Michigan As Revealed By Stable Carbon And Nitrogen Isotopes, Zachery G. Driscoll
Plankton Trophic Structure Within Lake Michigan As Revealed By Stable Carbon And Nitrogen Isotopes, Zachery G. Driscoll
Theses and Dissertations
Zooplankton represent a critical component of aquatic food webs in that they transfer energy from primary producers to higher trophic positions. However, their small size makes the application of traditional trophic ecology techniques difficult. Fortunately, novel techniques have been developed that can be used to elucidate feeding information between zooplankton species. I used the analysis of stable carbon and nitrogen isotope ratios to estimate the trophic structure of Lake Michigan's zooplankton community. The major zooplankton species, three size classes of seston, and seston from specific water column depths were collected in 2011 and 2012 for stable isotope analysis. Trophic position …
Sedimentology And Paleoecology Of Fossil-Bearing, High-Latitude Marine And Glacially Influenced Deposits In The Tepuel Basin, Patagonia, Argentina, Kathryn N. Pauls
Sedimentology And Paleoecology Of Fossil-Bearing, High-Latitude Marine And Glacially Influenced Deposits In The Tepuel Basin, Patagonia, Argentina, Kathryn N. Pauls
Theses and Dissertations
The glacial and non-glacial intervals of the Late Paleozoic Ice Age (LPIA) are of great interest because they are our best deep time analogue for Pleistocene climate change. The changes and adaptations of the biota, as seen in the rock record, can serve as a proxy for understanding future trends in Earth's climate system. Most of the known LPIA marine faunal data come from low-latitudinal regions, and thus have been used as a global proxy. However, modern organisms in the low-latitudes (far-field basins) respond differently to a changing climate relative to marine organisms in the polar regions (near-field basins). In …