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Climatic And Lithogenic Controls On Soil Organic Matter-Mineral Associations, Rota Wagai

Electronic Theses and Dissertations

Interactions of organic matter (OM) with soil mineral phases strongly affect the storage and dynamics of soil OM as well as other ecosystem processes. This study examined aspects of organo-mineral associations in soils at different scales. First, I assessed the potential controls of climate and parent rock type on organo-mineral associations using two sets of undisturbed tropical forest soils developed on two contrasting rocks along an altitudinal gradient in Borneo, Southeast Asia. Density fractionations showed that OM stored in surface mineral soils partitioned towards plant detritus fraction under cooler climates on both rock types. Thus climate exerted stronger control on …

Growth Increment Analysis Of Marine Bivalves From The North, Stephen D. Houk

Electronic Theses and Dissertations

This study aids in developing a sea surface temperature (SST) proxy with monthly temporal resolution using a combination of growth increment and stable isotope analyses of marine bivalves from the north coast of Peru. Faunal assemblages from the Siches and Ostra Base Camp archaeological sites contain shells of warm-tropical mollusks that currently live farther north in Ecuador. The presence of warm-tropical species in these sites and others as far south as 10"s latitude and dating prior to 5730 cal yr B.P. indicates a stable warm-water regime in the eastern tropical Pacific which subsequently changes to a modern temperate-water regime after …

The Spatial Variation Of Asian Dust And Marine Aerosol Contributions To Glaciochemical Signals In Central Asia, C. P. Wake, Paul Andrew Mayewski

Earth Science Faculty Scholarship

Short-term (6 months to 17 years) glaciochemical records have been collected from several glacier basins in the mountains of central Asia. The spatial distribution of snow chemistry in central Asia is controlled by the influx of dust from the large expanse of arid and semiarid regions in central Asia. Glaciers in the Northern and Western Tibetan Plateau show elevated concentrations and elevated annual fluxes of calcium, sodium, chloride, sulphate and nitrate due to the influx of desert dust from nearby arid and semi-arid regions. Glaciers in the Southeastern Tibetan Plateau show lower concentrations and lower annual fluxes of major ions …

Tb126: Vertical Trends In The Chemistry Of Forest Soil Microcosms Following Experimental Acidification, Ivan J. Fernandez

Technical Bulletins

A soil microcosm experiment was conducted (a) to compare dilute H2SO4, NH4NO3 fertilizer, and prilled S as possible experimental soil-acidifying treatments and (b) to observe soil chemical response to simulated throughfall and acidifying treatments. Simulated throughfall had a significant effect on soil chemistry, resulting in increased exchangeable bases and pH in the mineral soil horizons but little effect on the O horizon. Of the acidification treatments only simulated acid rain had significant effects on soil chemistry when compared to the control and the dry treatments. This reflected the relatively slow dissolution rate of the dry treatments coupled with the short …

Explorations, Vol. 1, No. 2, Jim I. Mead, Emilee M. Mead, Carol J. Bombard, Ronald B. Davis, Marcella H. Sorg

Explorations — A Journal of Research

The cover print is a multi-plate colored etching entitled Skull and Sun Dial, by Susan Groce, Associate Professor of Art at the University of Maine at Orono, where she teaches Printmaking and Drawing.

Articles include:

"The Quaternary"

"Ice Age Plants and Animals: Secrets of the Colorado Plateau," by Jim I. Mead and Emilee M. Mead

"Finding the Facts: Pieces of the Puzzle"

"On Location: In Search of the First Americans"

"A Temporal Vegetational Continuum: From Tundra to Forest," by Carole J. Bombard for Ronald B. Davis

"Anatomy of an Excavation," by Robson Bonnichsen

"What the Bones Tell Us," by …