bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurement of the Deposition and Fate of Sulfur‐Dioxide‐35 in a Pine Plantation
Authors: Gay D. W. , Murphy Charles E. 
Published: July 2010

AbstractAn experiment was carried out to determine the uptake rate and fate of SO2 absorbed by the forest canopy. The radioactive tracer, 35S was used. Branches of loblolly pine were exposed to 35SO2 in the field with a portable chamber. The exposed branches were excised and a sample of needles was immediately washed with distilled water. The needles and water collected in the field were analyzed for 35S content. The results indicated that a portion of the 35S could be washed from the needles and another portion was not removed with a water rinse. The portion that could not be removed by rinsing was absorbed at a rate and followed patterns of absorption, which suggested that absorption was controlled by stomatal diffusion, and thus was internal. The 35S that could be removed by rinsing appeared to be surface absorption. The average deposition velocity for the entire leaf surface of the pine plantation was 0.0041 m/s. The distribution of 35S was investigated by serial extractions. The fresh whole needles were rinsed in distilled water. Following rinsing, the dried and crushed leaf material was extracted with acetone, and then extracted with hexane. About 50% of the 35S activity was removed by the water rinse. About one‐third, 30 to 38%, of the 35S activity remaining after washing was found in each of the two extracts and about one‐third in the residual material left after extraction.
Design and Performance of a Large, Field Exposure Chamber to Measure Effects of Air Quality on Plants
Authors: Heagle Allen S. , Philbeck Robert B. , Ferrell Ronald E. , Heck Walter W. 
Published: July 2010

AbstractA 4.66‐m diam., 3.6 m tall, cylindrical open‐top field chamber was designed, constructed, and tested as a tool to measure the effects of air quality on plant function and yield. It is a larger version of the 3‐m diam. chamber that has been used to measure the effects of gaseous pollutants on crop plants. The new chamber has an aluminum‐channel frame covered with clear polyvinyl chloride plastic film. It is equipped with a frustum (truncated cone) that decreases ambient air ingress and can be fitted with a device to exclude rain (rain cap) for studies with simulated rain pH. During the daylight hours, the mean air temperature within the chamber was 0.6 °C greater than ambient on cloudy, cold days, 2.2 °C greater than ambient on partly cloudy, cool days, and 2.8 °C greater than ambient on sunny, warm days. The mean dew point temperature for a wide range of conditions was 0.7 ° greater inside than outside. Mean solar radiation in the chamber, with new plastic panels, was 15% less than ambient with a rain cap and 12% less with no rain cap. Charcoal filtration removed 78% of the O3 in ambient air; long‐term measurements during charcoal filtration showed that the mean O3 concentration in the chamber (all positions and heights) was 77% less than ambient suggesting little or no long‐term ingress through the top. Short‐term gradients in O3 concentrations existed (mostly near the top of the chamber) during infrequent periods of strong winds. During addition of approximately 0.09 µL L−1 of O3 to nonfiltered air, the mean (14‐d) O3 concentrations across all positions and heights varied by less than 0.005 µL L−1 of the overall mean.
Spatial Patterns in Elemental Concentrations of the Forest Floor across the North Central USA
Authors: Grigal D. F. , Ohmann L. F. 
Published: July 2010

AbstractForest floor material was sampled in 171 forest stands, representing five forest types, across the states of Minnesota, Wisconsin, and Michigan. Elemental concentrations of forest floor material were related to forest type, and for most elements, concentrations were also related to location defined by five sampling zones along a northwest‐southeast geographic gradient. Calcium, Mg, K, Na, and P decreased in concentration from west to east; Pb and Cd increased; Cu and Zn did not differ among zones, and although Ni differed, there was no pattern to those differences. The trends are consistent with atmospheric deposition of Ca, Mg, K, Na, and P from westerly soil‐derived sources and deposition of Pb and Cd from eastern anthropogenic sources.
Sources of Error in Analysis of Municipal Sludges and Sludge‐Amended Soils for Di(2‐ethylhexyl) Phthalate
Authors: Eiceman G. A. , Gardea‐Torresdey J. L. , O'Connor G. A. , Urquhart N. S. 
Published: July 2010

AbstractRapid quantitative determination of di‐(2‐ethylhexyl) phthalate (DEHP) in municipal sludge is described for capillary gas chromatography/mass spectrometry (GC/MS) using selected ion monitoring with isotope dilution techniques. Propagation of error through a four‐step technique is measured as an increase in variance with each additional step. Stepwise accumulated variation (as a percentage of total error) was GC/MS analysis with data reduction, 3%; analyst (sample preparation), 8%; heterogeneity of sludge, 30%; heterogeneity in sludge‐amended soil, 77%; and errors between planters, 100%. The relative standard deviation (RSD) associated with analysis of sludge alone was 16% at 51 mg kg−1 DEHP. Analysis precision was dependent on sample size and DEHP concentration. The RSD for a 13 mg kg−1 DEHP loading in soil/sludge mixtures for a greenhouse study was 26.5%. Detection limits for DEHP in sludges with rapid screening procedures were fixed by interfering extractable matrices.
Long‐Term Relationships between Molybdenum and Sulfur Concentrations in Redcedar Tree Rings
Authors: Guyette Richard P. , Cutter Bruce E. , Henderson Gray S. 
Published: July 2010

AbstractMolybdenum and S concentrations were determined in growth increments of 13 eastern redcedar (Juniperus virginana L.) trees from the Ozark region of Missouri. Chonologies were constructed, which dated from 1280 to 1960 for Mo, and from 1580 to 1960 for S. A 45% increase in Mo concentrations occurred between 1720 and 1860 when compared with the previous 440 yr. A decline in heartwood Mo concentration, beginning in 1860, is hypothesized to be due to increasing soil sulfate from the atmospheric deposition of S compounds. There was a 65% reduction in Mo concentration concomitant with a 44% increase in S concentration in redcedar heartwood formed after 1860. Sulfur and Mo concentrations were found to be negatively correlated in serial heartwood increments. Competition between sulfate and molybdate ions in soil solutions are thought to have decreased Mo in recent heartwood growth increments.
The Environmental Microbiology of Chlorinated Aromatic Decomposition
Authors: Boyle Michael 
Published: July 2010

AbstractThe difficulty in predicting the microbial degradation rates of such xenobiotic chemicals as chlorinated aromatic hydrocarbons necessitates that empirical data on decomposition be collected to model the environmental fate and transport of these recalcitrant compounds. A partial list of microorganisms reported to degrade chlorinated aromatic hydrocarbons is provided. The processes of degradation, including dehalogenation, cometabolism, and synergistic mineralization, are discussed as they pertain to these halogenated compounds. Adaptation through genetic exchange within a microbial community is addressed through a brief review of the physical‐chemical factors required for plasmid transfer in the laboratory. The ecological significance of gene recruitment in response to xenobiotic stress is also considered. Because chlorinated aromatic hydrocarbons were rare in the environment until a few decades ago, they provide a unique opportunity to study the evolution of multistep catabolic pathways for the degradation of compounds with novel chemical structures.
Herbicide Leaching and Distribution in Tilled and Untilled Soil
Authors: Hall J. K. , Murray M. R. , Hartwig N. L. 
Published: July 2010

AbstractLeaching and distribution of several pesticides, applied at recommended rates, were evaluated in a Hagerstown silty clay loam (Typic Hapludalf) by analyzing soil fractions and pan lysimeter percolates (PLP) collected at a soil depth of 122 cm under conventional tillage (CT) and no‐tillage (NT) corn (Zea mays L.) management. In general, maximum herbicide concentrations detected and mean total amounts in PLP were higher in 1985 than 1984 for both CT and NT, and were greater under NT conditions where more leachate was collected each year than in CT. Concentrations and amounts of simazine (6‐chloro‐N, N′‐diethyl‐1, 3,5‐triazine‐2, 4‐diamine) and atrazine (6‐chloro‐N‐ethyl‐N′‐(1‐methylethyl)‐1,3,5‐triazine‐2,4‐diamine) were generally more substantial in PLP than cyanazine (2‐[[4‐chloro‐6‐(ethylamino)‐1, 3,5‐triazin‐2yl] amino]‐2‐methylpropanenitrile), and metolachlor (2‐chloro‐N‐(2‐ethyl‐6‐methylphenyl)‐N‐(2‐methoxy‐1‐methylethyl) acetamide, particularly under NT conditions. In 1984, mean areal leaching losses (NT) were 0.6% (simazine, atrazine) and 0.15% (cyanazine, metolachlor) of applied rates (1.7 and 2.2 kg ha−1, respectively). In 1985, mean areal losses (NT) were 3.4% (simazine, atrazine) and 1.6% (cyanazine, metolachlor). Respective CT losses were <0.1% (1984) and ranged from 0.4 to 1.0% (1985). Where worst‐case conditions were considered (1985), mean leaching losses (simazine, atrazine) were 0.15 kg ha−1, therefore, at least 91% (1.55 kg ha−1) was retained and/or degraded within the soil profile or in the corn tissue after absorption. Soil core analysis corroborated PLP results revealing that simazine and atrazine were the most persistent and mobile herbicides, and were consistently detected at all soil depths to 122 cm. Differences in the yearly extent and magnitude of leaching losses were related strongly to rainfall distribution and number of leaching events proximal to the herbicide spray date.
Infiltration of Wastewater in a Newly Started Pilot Sand‐Filter System: I. Reduction of Organic Matter and Phosphorus
Authors: Pell Mikael , Nyberg Fred 
Published: July 2010

AbstractThe objective of the study was to monitor variables on P and organic matter reduction related to the wastewater purification process in a sand‐filter system constructed according to the directives issued by the National Swedish Environment Protection Board. Monitoring was conducted from start‐up until a steady state was reached. The system consists of a three‐chambered septic tank, a pilot sand‐filter, corresponding to the demand for one person, and eight sand‐filter columns. It was loaded with 67 L m−2 d−1 of an artificial wastewater. The effluent from the septic tank reached a steady state with respect to the chemical oxygen demand (COD) and P levels after 3 wk. By Day 78 the cumulative load of COD and P had been reduced by 37 and 48%, respectively. In the sand filter the reduction in COD started immediately and concentrations in the effluent remained low and steady from Day 18 until Day 78 when the last sampling was made. The total reduction in COD amounted to 91%. Effluent concentrations of P were initially low but increased as the experimental period progressed. The total decrease in P in the sand filter was 83%. The reduction in COD was highest in the upper 1.5 cm of the sand profile and was almost complete after 15 cm of infiltration; in contrast, P levels showed an overall decrease throughout the sand profile. The columns were less efficient at reducing COD but more efficient at decreasing P compared with the sand filter. The results from the columns suggest that anaerobic conditions had developed.
Self‐Diffusion of Selenate and Selenite in Overburden
Authors: Ahlrichs J. S. , Hossner L. R. 
Published: July 2010

AbstractSelf‐diffusion coefficients (D) for selenate (SeO2−4) and selenite (HSeO−3) were evaluated as a function of overburden pH (2, 3, 5, 7, 9) and volumetric water content (Θv = 0.22, 0.28, 0.34). Selenate self‐diffusion coefficients were least (D = 0.23 × 10−6 cm2 s−1 in overburden adjusted to pH 3 and Θv = 0.22 and greatest (D = 1.8 × 10−6 cm2 s−1 and 1.7 × 10−6 cm2 s−1) in overburden adjusted to pH 9 and Θv = 0.28 and 0.34. Self‐diffusion coefficients for HSeO−3 were 2 to 3 orders of magnitude slower than for SeO2−4. The most rapid HSeO−3 diffusion was observed at pH 2 and Θv = 0.34 (D = 53.2 × 10−9 cm2 s−1). The slowest was at pH 3 and Θv = 0.22 (D = 0.2 × 10−9 cm2 s−1). For both SeO2−4 and HSeO−3 the self‐diffusion coefficients increased with increasing water content and were related to adsorption characteristics of the soil and the Se species present at each soil pH.
Interactions of Hydrazine with Clays and Soils
Authors: Moliner Ana M. , Street J. J. 
Published: July 2010

AbstractThe nature and extent of hydrazine adsorption by clays and soils was found to be highly dependent on the suspension pH and on the types of surface functional groups. Under acidic conditions, replacement of Na+ by N2H+5 was the primary mechanism for hydrazine retention by every system studied. Most of the hydrazinium ion was readily desorbed by K+ from the surfaces of reference clays under acidic conditions, but remained absorbed on the surfaces of the Arredondo soil (Grossarenic Paleudults) horizons investigated. Under alkaline conditions, ion exchange was the predominant mechanism for hydrazine retention only in the case of montmorillonitic smectite. Kaolinite and two of the upper horizons of Arredondo soil adsorbed hydrazine via a different mechanism. Hydrazine retained on exchange sites was readily desorbed by K+.
Growth, Photosynthesis, and Chlorophyll Concentrations of Red Spruce Seedlings Treated with Mist Containing Hydrogen Peroxide
Authors: Hanson P. J. , McLaughlin S. B. 
Published: July 2010

AbstractThe effects of controlled exposures of mist (50–90 µm drop size) containing hydrogen peroxide (H2O2) on greenhouse‐grown red spruce (Picea rubens Sarg.) were studied for 16 wk coincident with the 1987 growing season. One‐year‐old seedlings were treated with simulated mist containing 0, 15, 59, or 235 µM H2O2 three times each week from 2400 to 0930 h. Height, diameter, net photosynthesis, respiration, chlorophyll, and dry weight measurements were made. After 16 wk of H2O2 exposures, no visible symptoms of foliar injury were evident. Similarly, no differences in net photosynthesis, respiration, or needle pigment concentrations were observed. Analysis of covariance of the dry weight data showed significantly greater dry matter in seedlings exposed to 235 µM H2O2 treatment vs. those treatments representing a range of ambient conditions (0, 15, and 59 µM). Mean relative growth rates were also the greatest for seedlings of the 235 µM treatment. Given these controlled exposure studies, it is hypothesized that concentrations of wet‐deposited H2O2 of up to twice current ambient maximums are unlikely to reduce red spruce seedling growth through direct impairment of leaf function.
Fate of Contaminants during Utilization of Peat Materials
Authors: Sheppard S. C. , Gibb C. L. , Hawkins J. L. 
Published: July 2010

AbstractSince peat soils are used for a variety of industrial purposes, the fate of contaminants in peat is of interest for environmental impact studies. Peat soils effectively retain many contaminants and can receive contaminants from both the atmosphere and groundwater. We investigated the fate of I, Se, Cs, U, and Pb in peats subjected to treatments simulating commercial processes. The soils were contaminated with three concentrations of the study elements and incubated for 3 yr. Subsamples were subjected to static pyrolysis, extraction with base, acid hydrolysis, and extraction with chelates to represent burning of peat, humic and fulvic acid extraction as industrial materials, carbohydrate extraction for single‐cell protein production, and application of chelate‐based fertilizers. The results are presented as product concentration ratios and percent recoveries. In several cases, the contaminants were markedly concentrated. As an example, food products produced from fungal culture in peat hydrolysates may contain 50‐fold higher U concentrations, on a dry wt. basis, than the original peat. Thus, contaminants are transferred to these products and this should be considered for environmental and human safety.
Hexazinone Persistence and Mobility of a Steep Forested Watershed
Authors: Lavy T. L. , Mattice J. D. , Kochenderfer J. N. 
Published: July 2010

AbstractThe mobility and persistence of hexazinone, 3‐cyclohexyl‐6‐(dimethylamino)‐1‐methyl‐1,3,5‐triazine‐2,4‐(1H,3H)‐dione, applied to a forest floor with a spot‐gun applicator was monitored for 43 months. A 15‐m buffer zone separated the steeply sloping (40%) treated area from a continuously flowing stream directly below. Automated in‐stream samplers revealed that the highest hexazinone concentrations in water routinely occurred during storm events, even when stream flow increased tenfold. More hexazinone ran off the treated watershed during winter months after tree leaves had fallen. During the first 24 months after treatment, 4.7% of total applied was detected in the stream sampled. Initially, forest litter was highly effective in adsorbing surface applications of hexazinone; however, after 5 months less than 0.2% of the original amount was retained in the litter. Over 99% of the hexazinone had dissipated from the top 30 cm of soil within 18 months after application. After 36 months, trace levels of hexazinone were detected in water samples collected soon after storms. However, no hexazinone was present in samples collected 43 months after application. Distribution coefficients for hexazinone adsorption revealed that this compound was retained most readily by the litter layer and decreasing adsorption was shown for soil deeper in the profile. Mean concentrations of hexazinone in green leaves of trees in the treated area ranged from 0.5 to 1.0 kg−1. Rapid dissipation of hexazinone in leaves lying on the floor suggested the possibility of recycling into existing vegetation.
Cadmium Distribution in Field‐Grown Fruit Trees
Authors: Korcak R. F. 
Published: July 2010

AbstractThe effect of soil applied Cd on Cd distribution in and growth of five species of fruit trees was investigated. Cadmium was applied at three rates (0, 5, and 10 mg kg−1 soil) as CdSO4 to orchard plots established at two pH levels, low (5.5) and high (6.5). Five fruit tree types were planted: ‘Gala’ apple (Malus domestica Borkh.) budded on M.26 (dwarfing) or MM.111 (semistandard) rootstocks, ‘Redskin’ peach (Prunus persica L.) on Lovell rootstock, ‘Stanley’ plum (Prunus domestica L.) on Myrobalon rootstock, and ‘Seckel’ pear (Pyrus communis L.) on seedling rootstock. The trees were grown for 6 yr, 7 yr in the case of pear, and leaf, bark, wood, fruit, and root Cd concentrations were monitored. Gala apple on both rootstocks accumulated very small concentrations of Cd, usually 0.1 mg kg−1 dry wt. in all tissues tested. Peach and plum were intermediate in Cd accumulation, but both still relatively low. Seckel pear had high Cd concentrations in all tissues including fruit flesh and peel. Pear leaf Cd concentrations were 2.0 mg kg−1 from the 10 mg kg−1 soil Cd application after 5 yr. Pear fruit peel and flesh showed elevated, although nonsignificant, Cd concentrations with increased Cd applied. There was little difference between bark and wood tissue Cd concentrations independent of tree type. Root Cd concentrations were highest for pear followed by peach and plum, and lowest in apple.
Selenium in the Southern Coast Range of California: Well Waters, Mapped Geological Units, and Related Elements
Authors: Tracy J. E. , Oster J. D. , Beaver R. J. 
Published: July 2010

AbstractA reconnaissance survey of 151 irrigation and stock wells was conducted in the southern coast range of California bounded by Alameda and San Joaquin counties in the north (37°45′N) and Ventura and Santa Barbara counties in the south (34°15′N). Selenium concentrations in 11 wells exceeded 20 µg/L, the recommended water quality guideline for irrigation water. Wells with Se concentrations >2 µg/L were associated with nearby surface Pliocene and Miocene (P < 0.001) marine rocks based on Pearson's chi‐square analysis. Selenium was linearly related (P < 0.001) to electrical conductivity (EC), SO4, and P concentrations. Improved regression fits resulted from stratification by Pliocene and Miocene marine surface rocks; stratification also improved the regression fit (P < 0.001) between Se and Cl. The multiple linear regression equation relating Se to EC and P within 2.5 km of Pliocene surface rocks produced an R2 of 0.74 and a standard error of estimate of 11 µg Se/L. We conclude that either both Pliocene and Miocence rocks are Se sources, or that Pliocene rocks are positional markers locating recently uplifted, Sebearing Miocene rocks. Also, surface rock geology and well water composition (EC, P) would be useful information to locate wells that are likely to contain high levels of Se.
Sulfur, Nitrogen, and pH Levels in Wisconsin Precipitation
Authors: Andraski T. W. , Bundy L. G. 
Published: July 2010

AbstractPrecipitation is an important source of S and to a lesser extent N for agricultural crops and natural ecosystems. Reductions in S and N emissions have occurred and additional revisions in air quality standards will be expected to further reduce the amounts of nutrients such as S and N in precipitation. This study was conducted to determine current nutrient deposition rates and precipitation pH levels at 10 sites in important agricultural areas of Wisconsin. Bulk precipitation samples were collected at 10‐d intervals for a 2‐yr period from Nov. 1985 to Oct. 1987. Average annual SO4‐S deposition was 11 kg S ha−1 in northwestern Wisconsin and 23 kg S ha−1 in the south. These S deposition rates are approximately 42% less than the amounts found in a Wisconsin study conducted from 1969 to 1971. Despite this apparent decrease in S deposition, most of the S requirement for crop production is still likely to be provided by S in precipitation in most areas of the state. Annual average NO3‐N deposition also differed geographically with 4.2 kg N ha−1 deposited in the northwest and 8.4 kg N ha−1 in the south. Average annual NH4‐N deposition was 8.7 kg N ha−1 but showed no geographical trend, and variations among sites were probably influenced by point sources. For most sites, annual deposition amounts of nutrients were similar both years, although concentrations were lower during a year with above‐normal precipitation. The annual volume‐weighted mean pH ranged from 5.1 to 5.9 in a year with above‐normal precipitation and from 3.4 to 4.5 in a year with slightly below‐normal precipitation.
Pine Growth Variation Associated with Overburden Rock Type on a Reclaimed Surface Mine in Virginia
Authors: Torbert J. L. , Burger J. A. , Daniels W. L. 
Published: July 2010

AbstractThis study was designed to compare the effects of two overburden spoil types and various mixtures of the two spoils on the performance of pitch × loblolly hybrid pine (Pinus × rigitaeda). Sandstone and siltstone overburden were used to create five rock mix treatments: pure sandstone (SS), pure siltstone (SiS), a 2:1 SS/SiS mix, a 1:1 SS/SiS mix, and a 1:2 SS/SiS mix. Tree survival was not affected by rock mix, but growth was greatly affected. The greatest growth response occurred on the SS treatment and decreased as the amount of siltstone increased in the rock mix. The average stem volume of trees on the SS treatment was nearly five times greater than trees on the SiS treatment. The coarse fragment content of the SS (52%) was much lower than the SiS (72%), thus providing a greater volume of fine earth (<2 mm) for water retention and root exploitation. The pH of the SS was much lower than SiS (5.7 vs. 7.1), and available Mn was higher in the SS than in the SiS (540 vs. 160 mg kg−1 foliar Mn). The results of this study demonstrate the need to consider the effects of various overburden types on tree growth when forest land is the designated post‐mining land use.