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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Paleoecology and Land-Use of Quaternary Megafauna from Saltville, Virginia

Simpson, Emily 01 May 2019 (has links) (PDF)
Land-use, feeding habits, and response to seasonality by Quaternary megaherbivores in Saltville, Virginia, is poorly understood. Stable isotope analyses of serially sampled Bootherium and Equus enamel from Saltville were used to explore seasonally calibrated (δ18O) patterns in megaherbivore diet (δ13C) and land-use (87Sr/86Sr). Overall, this dataset suggests an open forest with relatively constant temperatures year round that were similar to modern conditions. Neither Bootherium or Equus individuals spent a significant amount of time at higher elevations in the nearby Blue Ridge geologic province. These analyses provide a unique perspective on long-term response of large mammals to climatic shifts and their impact on local ecosystems. Results are also relevant to modern conservation decisions, especially those surrounding highland grassy balds in the Appalachians, and their maintenance by grazing pressure.
2

Surface-Soil Properties of Alder Balds with Respect to Grassy and Rhododendron Balds on Roan Mountain, North Carolina—Tennessee

Donaldson, James T., Dinkins, Zachary C., Levy, Foster, Nandi, Arpita 01 June 2014 (has links)
We analyzed soils in Alder Bald, Grassy Bald, and Rhododendron Bald communities on Roan Mountain to infer the influence of vegetation on soil and to help guide management strategies. In all vegetation types, soils were acid (pH = 4–5) sandy loams. We found vegetation-associated differences for organic content, cation exchange capacity, acidity, two plant macronutrients (K, Mg), and three cations (Fe, Na, Zn). We predicted that nitrogen compounds would be highest in the Alder Bald because Alnus viridis ssp. crispa (Green Alder) can harbor nitrogen-fixing bacteria. Organic content was highest at the alder-bald sites, ammonium was similar among vegetation types, and nitrate was high at only some sample sites. The unique soil properties of the Alder Bald community, its likely role in primary succession, and its documentation as a long-standing community type on Roan Mountain suggest that management should be directed towards its conservation.

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