Trends in soil chemistry are studied on a 300 meter long hillslope in the Cascade Mountain Range of southwestern British Columbia. Although trends are not wholly consistent from horizon to horizon, the following general statements can be made: pH tends to increase downslope; exchangeable calcium, exchangeable magnesium and cation exchange capacity decrease noticeably downslope; carbon may decrease slightly downslope; nitrogen, carbon/nitrogen ratio, percent base saturation, exchangeable sodium and exchangeable potassium remain effectively constant downslope. Soil chemistry is shown to be related to horizon, slope position and parent material. Variability among chemical species increases in the sequence: pH, percent base saturation, carbon/nitrogen ratio, cation exchange capacity, nitrogen, exchangeable calcium, percent carbon, exchangeable potassium, exchangeable sodium, exchangeable magnesium. Variability fluctuates among soil horizons but not so noticeably with slope position. A slight increase in variability with the size of the area sampled is evident. / Land and Food Systems, Faculty of / Graduate

Groundwater contamination and soil salinisation are a major environmental problem worldwide. Living organisms depend largely on groundwater for their survival and its pollution is of course of major concern. It therefore goes without saying that remedial processes and understanding of the mathematical models that describe contaminant transport is of great importance. The theory of contaminant transport requires understanding of the water ow even at the microscopic level. In this study we focus on macroscopic deterministic models based on di erential equations. Here contaminant will refer to nonreactive contaminant. We aim to calculate Lie point symmetries of the one-dimensional Advection-di usion equation (ADE) for various forms of the di usion coe cient and transport velocity. We aim to employ classical Lie symmetry techniques. Furthermore, reductions will be carried out using the elements of the optimal systems. In concluding, the ADE is analyzed for selected forms of the the di usion coe cient and transport velocity via the potential symmetry method. For the potential symmetries obtained, we investigate the associated invariant solutions.

Non-tuberculous mycobacteria (NTM) cause opportunistic lung disease though environmental exposure pathways. Among the United States, Hawaii has a significantly higher infection rate. Preliminary studies have shown certain environmental factors, such as phosphorus and other select soil geochemical characteristics, to be statistically significant to NTM occurrence. However, a model to predict NTM occurrence based on soil geochemistry had yet to be attempted. A selection of 40 NTM positive and 40 NTM negative soils from Oahu were selected for a geochemical analysis to search for possible correlations to mineralogy and elemental abundances that may promote, or inhibit, NTM growth in the environment. Oahu results were compared with soil chemistry from the Kilauea and Kohala areas of Hawaii Island. Parameters included mineralogy, total organic carbon (TOC), pH, major elements, and trace elements. Statistical analyses performed include: student's t-test, multidimensional hypothesis tests, principal components analysis (PCA), and multidimensional statistical analysis. The data for Oahu showed NTM presence correlated with 1:1 clays and NTM absence correlated with goethite, 2:1 clays, Nb, Ce, La, Ba, and Rb. Kohala soil data showed NTM presence correlated with Al2O3, Ce, Sc, and Sm and NTM absence correlated with rainfall, Cr, Pb, and S. Kilauea data showed NTM presence correlated with TOC, pH, P, mafic silicate minerals, and Pb and NTM absence correlated with transition metals and oxides such as TiO2, Zr, and Nb. The results of the multidimensional statistical analysis were used to build a predictive model of NTM occurrence. The best model for Oahu had an accuracy of 65.9%, while Kohala had an accuracy of 71.7% and Kilauea 79.9%. A selection of five Hawaiian rock samples consisting of basalt, volcanic glass, and saprolite were used to culture clinically significant M. abscessus and visualize the effect mineralogy has on NTM growth. NTM cells were found on all mineral surfaces. However, volcanic glass was shown to visibly increase NTM growth and survival. As time passes, the ability to predict soil features that enhance NTM predictability decreases from 79.9% in modern Kilauea soils, to 71.7% in 0.17 Ma Kohala soils, to 65.9% in ~2 Ma Oahu soils. With age, it appears that distinct properties that enhance NTM survival are either erased or weathered to a more uniform state. Nonetheless, the NTM risk remains high in Hawaii due to environmental factors.

En omfattande multiproxyanalys har utförts på provtagningar från två vattenhål belägna i Skåneregionen i Sverige. Denna mångsidiga analys involverade flera aspekter, inklusive markkemi, entomologi, mikrofossiler och makrofossiler. Resultaten från markkemianalysen avslöjade betydande skillnader mellan de två vattenhålen. Vattenhål 1 uppvisade en högre halt av organiskt material, vilket tyder på högre glödförluster och högre värden av maximal magnetisk susceptibilitet (MS550) och totalfosfat (CitPOI). För att ytterligare karakterisera egenskaperna hos vattenhålen användes även analyserna infrarödspektroskopi (NiR) och röntgenfluorescens (XRF).   Vattenhål 2 visade tecken på att ha fyllts med bosättningsavfall från platsen. Detta stöddes av markkemiresultaten som visade en lägre halt av organiskt material samt närvaron av antropogena material, såsom förkolnade frön, träkol, bränd lera, ben och keramikfragment.   Makrofossilanalysen avslöjade intressanta fynd. I vattenhål 1 hade växter som etternässla (Urtica urens) och kråkklöver (Comarum palustre) deponerats, tillsammans med enstaka exemplar av Thrips major Uzel. I kontrast bestod de förkolnade fröna från vattenhål 2 huvudsakligen av ogräs, inklusive svinmålla (Chenopodium album) och nattskatta (Solanum nigrum). Det fanns även spår av sädeskorn som korn (Hordeum vulgare), samt oidentifierade fragment av sädeskorn. Resultaten från makrofossilanalysen indikerade att materialet från vattenhål 1 härstammar troligtvis från forntida mänskliga aktiviteter, som odling.   Mikrofossilanalysen visade att det inte fanns några kiselalger (diatoméer) i något av vattenhålen. Sammantaget antyder resultaten från multiproxyanalysen att vattenhål 1 hade genomgått minst tre olika faser i sin historia, medan vattenhål 2 hade fyllts med jord och material från en bosättningsliknande plats, vilket gjorde det svårt att entydigt tolka själva vattenhålets historia och funktion.

No description available.

The current silvicultural regimes of Pinus radiata plantations in New Zealand with wider initial tree spacings have created the potential for increased growth of understorey vegetation. A consequence of this is that the response of P. radiata to P fertiliser is expected to be more influenced by the interaction between the P fertiliser, the tree and the understorey vegetation than was the case in the past. The objectives of this study were to investigate the influence of different rates of a soluble and a sparingly-soluble P fertiliser (Triple superphosphate and Ben-Geurier phosphate rock) and weed control, and their interactions, on soil P chemistry and the growth and P uptake of 4-5-year-old second-rotation P. radiata on an Allophanic Soil (Kaweka forest) and a Pumice Soil (Kinleith forest). The results showed that the application of P fertilisers had no effect on P. radiata growth at both field trial sites two years after this treatment, although it increased radiata needle P concentration. However, at both sites, the understorey vegetation removal treatment increased tree diameter at breast height and basal area. At the highly P-deficient (Bray-2 P 4 µg g-1) Kaweka forest, the presence of understorey (bracken fern and some manuka) reduced resin-Pi and Olsen P concentrations, but at the moderate P fertility (Bray-2 P 13 µg g-1) Kinleith forest, the understorey (Himalayan honeysuckle, buddleia and some toetoe) increased Bray-2 P, resin-Pi, and Olsen P concentrations. A glasshouse study on P. radiata seedlings was conducted to test the hypothesis that when ryegrass (Lolium multiflorum) is grown with P. radiata, it increases radiata needle P concentration, while when broom (Cytisus scoparius L.) is grown with P. radiata, it has no effect. The acid phosphatase activity in the rhizosphere of P. radiata was higher when radiata was grown with broom than that when it was grown with ryegrass. This is consistent with the higher P concentration in needles of radiata grown with broom than that of radiata grown with ryegrass, in the absence of P fertiliser addition. However, when P fertiliser was added (50 and 100 µg P g-1 soil) the needle P concentration of radiata grown with broom was lower than that when radiata was grown with ryegrass.

No description available.

No description available.

In the first phase of the study, the effect of five Safol surfactants on the aqueous solubility of phenanthrene and acenaphthene was determined. The fixed variables were temperature and ionic strength, while surfactant concentration and pH were varied. Quantification of the polyaromatic hydrocarbons (PAHs) was conducted by UV-Visible spectrophotometry. The surfactants had little or no effect on analyte solubilisation below the critical micelle concentration (CMC) while a linear relationship between surfactant concentration and amount of solubilised phenanthrene was observed above CMC concentrations. Safol 45E5 had the highest phenanthrene molar solubilisation ratio (0.83) of the five surfactants tested. The solubilisation of phenanthrene increased marginally (4.1 % for Safol 45E12 and 15.2 % for Safol 45E7) by decreasing the pH from 8 to 5. The concentration of solubilised acenaphthene was 8.4 % higher than phenanthrene in a 1 mM solution of Safol 45E7. The aqueous solubility of phenanthrene was enhanced 11.0, 21.2, 19.6, 15.9 and 14.7 times in 1 mM solutions of Safol 45E3, 45E5, 45E7, 45E9 and 45E12 respectively. Seasand, Longlands sand, Longlands soil and a standard soil sample were spiked with the two PAHs and aged for two weeks. API sludge provided by Sasol and unspiked samples of the above mentioned sorbents were subjected to determinations of organic matter content, particle size distribution and moisture content. The spiked soils and sands and the sludge samples were then washed in various concentrations of Safol 45E7 (0.5, 1.0 and 2.0 mM) at the same temperature used in the solubility studies. A soil mass to solution volume of lg to 10 mL was used. Analyses of the soil and sand samples were conducted by High Pressure Liquid Chromatography (HPLC). Using a 2 mM Safol 45E7 surfactant solution, 100 % and 90 % of phenanthrene and acenaphthene were respectively extracted from Longlands sand and 88 % and 100 % of phenanthrene and acenaphthene were removed from seasand. 8.4 % phenanthrene and 8.17 % of acenaphthene was removed from Longlands soil, while 7.03 % phenanthrene and 6.64 % acenaphthene was removed from the standard soil sample. In the sand desorption studies, the amount of desorbed contaminants initially increased rapidly with increasing surfactant concentration, before levelling off at equilibrium. The amount of desorbed acenaphthene and phenanthrene increased exponentially with increasing surfactant concentration while contaminant concentrations decreased with increasing time in the Longlands soil and standard soil desorption experiments. Dry API sludge samples were also subjected to soil washing studies. The washed samples were Soxhlet extracted and analysed by gas chromatography. The 0.5 mM and 1 mM Safol 45E7 washed sludge samples showed respective phenanthrene peak area percent reductions representing a 44 % and 47 % extraction of phenanthrene from the API sludge. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

Roads alter the ecological landscape and affect the function and composition of nearby soil chemistry and plant communities in an area of impact termed the “edge-effect zone”. While the 6.3 million kilometers of roads in the US cover only about 1% of the land, the edge effect zone around these roads has been estimated to occupy nearly 20% of the total land area in the US (Forman 2000). The objective of this study was to examine the spatial extent of transported materials and impacts on forest soil and vegetative communities immediately surrounding roadways based on road types classified as “Highway,” “Two-Lane Paved,” and “Gravel.” This research was located within two watersheds in the state of Vermont, in areas where a substantial area of forest existed adjacent the roadway. Using GIS mapping, transects were constructed at right angles to the road, and samples were gathered at the Shoulder, Ditch, Backslope, 10m from the edge of the forest, and 50m from road center during the summer of May 2009 to August 2009. Soil samples were analyzed for a suite of nutrients and physical characteristics, as well as heavy metals. The forest composition and percent area coverage by species of herbaceous flora and woody shrubs were also recorded. The main effects from roads were dependent on the extent of clearing and topography modification required for a roadway. The spatial extent of these modifications was correlated positively with road use intensity. Highways have the greatest ecological impact and gravel roads the least impact. The cleared area defines how much sunlight is available to plant communities and the distance that road pollutants will travel. Some heavy metals (such as Pb, Cd, Ni and Zn) were correlated positively with road use intensity. Gravel roads have higher calcium content in nearby soil when compared to other road types. This is most likely due to mobilized dust from the road base. Proximity to all road types had neutralizing effects on the soil pH relative to the acidic native forest soil. Changes in microtopography next to the road have marked effects on the composition of plant communities through maintenance and direction of water flow. Ditch areas support wetland plants, and have greater soil moisture and sulfur content, while plant communities closer to the road are characteristic of drier upland zones. The area past the edge of the forest does not appear to be affected chemically or physically by any of the road types, possibly due to the dense vegetation that develops outside of the right-of-way. To reduce the ecological footprint of future road development, road corridors should be narrowed, traffic consolidated to mass transit systems such as busses or railroad, and buffer zones of vegetation next to the right-ofway should be encouraged to contain the spread of pollutants.