Soil samples were collected from the major horizons of Scottish upland Calluna moorland podzols derived from quartzite, Devonian and Torridonian sandstone, or granite or granitic tills. All soil was subjected to routine chemical analysis and the soil derived from granite was also mineralogically analysed. The results were studied in relation to finding evidence for potential acidification effects of atmospheric deposition. Strong relationships were observed between acid deposition parameters, particularly the mobile anion concentrations, and soil pH measured in water and soil extractable Al in all the horizons from podzols derived from sandstones and quartzites. These are discussed in Chapter 2. When looking for ameliorative effects, less clear trends were observed between atmospheric base cation inputs and soil "damage" parameters, possibly due to the distribution of the data. Soils derived from granite or granitic till showed relationships between soil pH in water or in CaCl2 pastes and H+ deposition, and between soil extractable Al and H+ deposition (Chapter 3). In addition, atmospheric inputs of base cations showed strong acid ameliorative properties in these soils. The relative importance of marine- and non-marine base cations in the calculation of critical loads for soil is examined in Chapter 4. The accumulation of N in the surface horizons along a pollution gradient is discussed in Chapter 5. At low to moderate total and NH4+ deposition (i.e., 10 and 5 kg ha-1 yr-1 respectively), soil total N and soil C:N ratio increased linearly with atmospheric N deposition. In spite of the N accumulation, C accumulated relatively faster than N, to increase the C:N ratio at sites with low to moderate N deposition. At total N or NH4+ deposition values above 8.8 and 4.0 kg ha-1 yr-1 respectively, the C:N ratio declined with increasing N deposition.

Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references (leaves 122-135). Also available in electronic version. Access restricted to campus users.

Thesis (M.S.)--University of Tennessee, Knoxville, 2003. / Title from title page screen (viewed Sept. 19, 2003). Thesis advisor: Wayne T. Davis. Document formatted into pages (xii, 134 p. : ill. (some col.), maps). Vita. "PM2.5" in abstract "2.5" is subscript. Includes bibliographical references (p. 112-115).

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona, 1989. / Includes bibliographical references (leaves 169-174).

Thesis (M.S.)--University of Tennessee, Knoxville, 2008. / Title from title page screen (viewed on Sept. 21, 2009). Thesis advisor: John S. Schwartz. Vita. Includes bibliographical references.

Thesis (M.A.)-- Florida State University, 2006. / Advisor: Joseph F. Donoghue, Florida State University, College of Arts and Sciences, Dept. of Geological Sciences. Title and description from dissertation home page (viewed Jan. 2, 2007). Document formatted into pages; contains x, 103 pages. Includes bibliographical references.

Indiana University-Purdue University Indianapolis (IUPUI) / I examined interactions between plants and the environment they live in along the soil-plant-atmospheric continuum and addressed the effects of drought and acid deposition on plant water use. Using a novel stable isotope technique, I showed that plant water source utilization can be modulated in some species based on the soil and atmospheric conditions they experience, whereas others only access a single subsurface water source. By modeling cuticular conductance in multiple plant species, I showed that the variability of cuticular conductance across species is largely related to the changes in leaf water potentials between pre-dawn and midday measurements collected in field studies. I also assessed the individual and combined effects of soil water stress and atmospheric water stress on plant productivity by developing a new methodology, which can be used across scales. In doing so, I found that in deciduous broad-leaf forests, periods of high vapor pressure deficit caused sufficient hydraulic stress to reduce plant productivity more than low soil water content alone, and often reduced productivity to levels equal to periods of both low soil water stress and high vapor pressure deficit. Utilizing historical data from a whole forest acidification experiment, I was able to link the stress of nutrient deficiencies caused by acid deposition (specifically calcium) to increases in plant water utilization. This was the first observation of such an effect at the ecosystem scale and could have significant implications for understanding water availability in the future. Finally, I assessed a common method for extracting cellulose from tree rings for isotope analyses, which is often used to determine the historical water use efficiency of plants. I was able to determine chemical alteration to the cellulose molecule using stable isotope measurements and spectroscopy. The chemical modification seems to be systemic and therefore could be addressed through mathematical corrections to existing data. Having accurate values of plant water use efficiency is extremely important for understanding how different stressors in the past changed the way plants used their water resources. My series of studies provide new insights and tools to evaluate the plant-environment interactions in current and future environments.

Thesis (M.S.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains viii, 169 p. : ill. (some col.), col. maps. Includes abstract. Includes bibliographical references (p. 62-67).

No description available.

Two soils from the Fernow Experimental Forest near Parsons, West Virginia were characterized and evaluated in terms of their susceptibility to enhanced soil acidification via acidic atmospheric inputs. After initial physical, chemical, and mineralogical characterization, the soils were analyzed for their ability to adsorb and retain sulfate (SO₄²⁻) through a series of batch adsorption and desorption experiments. Reconstructed soil profiles were then subjected to water leaching as the preliminary step to a base release study in which each soil will be placed under simulated acid rain and evaluated for base cation release and subsequent changes in soil chemistry. Experiments with SO₄²⁻ adsorption and desorption divide the soils into two categories: (i) shallow surface horizons with high organic matter and little Fe oxide content which had little ability to adsorb additional SO₄²⁻ and low capacity to retain SO₄²⁻; and (ii) deeper subsurface soils with low organic matter and high Fe oxide content which could adsorb SO₄²⁻ at solution concentrations above 0.5 mmol/L. All soil horizons desorbed SO₄²⁻ and had no ability for additional adsorption at solution concentrations below 0.5 mmol/L, which implies that the site may be saturated with respect to natural conditions. Initial mass (IM) and Langmiur modeling were used to illustrate SO₄²⁻ dynamics and make correlations with soil physical, chemical, and mineralogical properties. Fe oxides and Al-saturated organic matter were shown to be the preferential sites for SO₄²⁻ adsorption but may be already saturated or very near saturation. Preliminary results from the base release study indicate that the two soils are dominated by different chemical processes and hence release ions into soil solution at different rates. Ion release is shown to be a function of both reactions on the exchange complex and the dissolution of mineral components. / Master of Science