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51.
Residual dynamics of thiacloprid in medical herbs marjoram, thyme, and camomile and in soil 总被引:2,自引:0,他引:2
Thiacloprid is a new insecticide of the chloronicotinyl family. To assess its risk after application, residual characteristics of thiacloprid in marjoram, thyme, and camomile and in soil were studied under field conditions. The active ingredient was extracted from the plant material using a mixture of acetone-water. After filtration, the extract was concentrated to the aqueous phase, diluted with water, and portioned against ethyl acetate on a matrix solid phase dispersion column. Thiacloprid was extracted from soil using a mixture of methanol-water, filtered, and re.extracted (clean up) with dichloromethane. The residues were quantified using HPLC-MS-MS. The methods were validated by recovery experiments. Thiacloprid residues in marjoram, thyme, and camomile and in soil persisted beyond 10, 14, 14, and 21 d but no residues were detected after 14, 21, 21, and 28 d, respectively. The data obtained in this study indicated that the biexponential model is more suitable than the first-order function to describe the decline of thiacloprid in fresh marjoram, fresh thyme, and dried camomile flowers with half-life (t1/2) of 1.1, 0.7, and 1.2 d, respectively. However, both the first-order function and biexponential model were found to be applicable for dissipation of thiacloprid in soil with almost the same t1/2 values of 3.5 and 3.6 d. The results indicated that thiacloprid dissipates rapidly and does not accumulate in the tested herbs and in soil. 相似文献
52.
The role of private rural properties for conserving native vegetation in Brazilian Southern Amazonia
Siqueira Auberto Ricaurte Luisa Fernanda Borges Guilherme Augusto Nunes Gustavo Manzon Wantzen Karl Matthias 《Regional Environmental Change》2018,18(1):21-32
Regional Environmental Change - The State of Mato Grosso in Brazil has undergone intensive land use changes over the past decades. Native ecosystems have been converted into agrosystems for the... 相似文献
53.
Oetken M Stachel B Pfenninger M Oehlmann J 《Environmental pollution (Barking, Essex : 1987)》2005,134(1):87-95
The ecotoxicological implications of a flooding disaster were investigated with the exceptional Elbe flood in August 2002 as an example. Sediment samples were taken shortly after the flood at 37 sites. For toxicity assessment the midge Chironomus riparius (Insecta) and the mudsnail Potamopyrgus antipodarum (Gastropoda) were exposed to the sediment samples for 28 days. For a subset of 19 sampling sites, the contamination level and the biological response of both species were also recorded before the flood in 2000. The direct comparison of biological responses at identical sites revealed significant differences for samples taken before and immediately after the flood. After flood sediments of the river Elbe caused both higher emergence rates in the midge and higher numbers of embryos in the mudsnail. Contrary to expectations the toxicity of the sediments decreased after the flood, probably because of a dilution of toxic substances along the river Elbe and a reduction in bioavailability of pollutants as a result of increasing TOC values after the flood. 相似文献
54.
Input of trichloroacetic acid into the vegetation of various climate zones--measurements on several continents 总被引:2,自引:0,他引:2
Weissflog L Krüger G Elansky N Putz E Pfennigsdorff A Seyfarth KU Nüchter M Lange C Kotte K 《Chemosphere》2003,52(2):443-449
Trichloroacetic acid (TCA, CCl(3)COOH) is a phytotoxic chemical. Although TCA salts and derivates were once used as herbicides to combat perennial grasses and weeds, they have since been banned because of their indiscriminate herbicidal effects on woody plant species. However, TCA can also be formed in the atmosphere. For instance, the high-volatile C(2)-chlorohydrocarbons tetrachloroethene (TECE, C(2)Cl(4)) and 1,1,1-trichloroethane (TCE, CCl(3)CH(3)) can react under oxidative conditions in the atmosphere to form TCA and other substances. The ongoing industrialisation of Southeast Asia, South Africa and South America means that use of TECE as solvents in the metal and textile industries of these regions in the southern hemisphere can be expected to rise. The increasing emissions of this substance--together with the rise in the atmospheric oxidation potential caused by urban activities, slash and burn agriculture and forest fires in the southern hemisphere--could lead to a greater input/formation of TCA in the vegetation located in the lee of these emission sources. By means of biomonitoring studies, the input/formation of TCA in vegetation was detected at various locations in South America, North America, Africa, and Europe. 相似文献
55.
56.
Pedro D. Fernández Tobias Kuemmerle Matthias Baumann H. Ricardo Grau José A. Nasca Alejandro Radrizzani 《Journal of Land Use Science》2020,15(1):52-68
ABSTRACTImpacts of cattle production vary among different production systems, but data on their distribution is scarce for most world regions. In this work, we combine datasets on cattle vaccination locations and land cover in a regression framework to define and map major cattle production systems in the Argentinean Dry Chaco. We also explore how cattle occurrence relates to spatial determinants. Results indicate that the region harbors about 5.5 million heads. Cattle density was mainly described by the share of pasture (69.9%), cropland (28.1%) and aridity (23.8%). We identified 12-major cattle production systems: six cow-calf, three whole-cycle, and three fattening systems. Of these, four systems had high woodland cover (>85%). Data generated is available in a website. Understanding the distribution of cattle production systems is important to assess the environmental impacts of beef production at broad scales. Integrating vaccination data with land-cover information provides a promising avenue to identify livestock systems. 相似文献
57.
Matthias Schmid Torsten Hothorn Kelly O. Maloney Donald E. Weller Sergej Potapov 《Environmental and Ecological Statistics》2011,18(4):709-733
Indices of biotic integrity have become an established tool to quantify the condition of small non-tidal streams and their
watersheds. To investigate the effects of watershed characteristics on stream biological condition, we present a new technique
for regressing IBIs on watershed-specific explanatory variables. Since IBIs are typically evaluated on an ordinal scale, our
method is based on the proportional odds model for ordinal outcomes. To avoid overfitting, we do not use classical maximum
likelihood estimation but a component-wise functional gradient boosting approach. Because component-wise gradient boosting
has an intrinsic mechanism for variable selection and model choice, determinants of biotic integrity can be identified. In
addition, the method offers a relatively simple way to account for spatial correlation in ecological data. An analysis of
the Maryland Biological Streams Survey shows that nonlinear effects of predictor variables on stream condition can be quantified
while, in addition, accurate predictions of biological condition at unsurveyed locations are obtained. 相似文献
58.
Anwar Zahid M. Q. Hassan G. N. Breit K.-D. Balke Matthias Flegr 《Environmental geochemistry and health》2009,31(Z1):69-84
Accumulations of iron, manganese, and arsenic occur in the Chandina alluvium of southeastern Bangladesh within 2.5 m of the
ground surface. These distinctive orange-brown horizons are subhorizontal and consistently occur within 1 m of the contact
of the aerated (yellow-brown) and water-saturated (gray) sediment. Ferric oxyhydroxide precipitates that define the horizons
form by oxidation of reduced iron in pore waters near the top of the saturated zone when exposed to air in the unsaturated
sediment. Hydrous Fe-oxide has a high specific surface area and thus a high adsorption capacity that absorbs the bulk of arsenic
also present in the reduced pore water, resulting in accumulations containing as much as 280 ppm arsenic. The steep redox
gradient that characterizes the transition of saturated and unsaturated sediment also favors accumulation of manganese oxides
in the oxidized sediment. Anomalous concentrations of phosphate and molybdenum also detected in the ferric oxyhydroxide-enriched
sediment are attributed to sorption processes. 相似文献
59.
Matthias Demuzere Nicole P.M. van Lipzig 《Atmospheric environment (Oxford, England : 1994)》2010,44(10):1341-1355
In order to make projections for future air-quality levels, a robust methodology is needed that succeeds in reconstructing present-day air-quality levels. At present, climate projections for meteorological variables are available from Atmospheric-Ocean Coupled Global Climate Models (AOGCMs) but the temporal and spatial resolution is insufficient for air-quality assessment. Therefore, a variety of methods are tested in this paper in their ability to hindcast maximum 8 hourly levels of O3 and daily mean PM10 from observed meteorological data. The methods are based on a multiple linear regression technique combined with the automated Lamb weather classification. Moreover, we studied whether the above-mentioned multiple regression analysis still holds when driven by operational ECMWF (European Center for Medium-Range Weather Forecast) meteorological data. The main results show that a weather type classification prior to the regression analysis is superior to a simple linear regression approach. In contrast to PM10 downscaling, seasonal characteristics should be taken into account during the downscaling of O3 time series. Apart from a lower explained variance due to intrinsic limitations of the regression approach itself, a lower variability of the meteorological predictors (resolution effect) and model deficiencies, this synoptic-regression-based tool is generally able to reproduce the relevant statistical properties of the observed O3 distributions important in terms of European air quality Directives and air quality mitigation strategies. For PM10, the situation is different as the approach using only meteorology data was found to be insufficient to explain the observed PM10 variability using the meteorological variables considered in this study. 相似文献
60.
Jörn Budde Monika Heiermann Teresa Suárez Quiñones Matthias Plöchl 《Waste management (New York, N.Y.)》2014,34(2):522-529
Lab-scale experiments were conducted to assess the impact of thermobarical treatment of cattle waste on anaerobic digestion. Treatment was at temperatures of 140–220 °C in 20 K steps for a 5-min duration. Methane yields could be increased by up to 58% at a treatment temperature of 180 °C. At 220 °C the abundance of inhibitors and other non-digestible substances led to lower methane yields than those obtained from untreated material. In an extended analysis it could be demonstrated that there is a functional correlation between the methane yields after 30 days and the formation rate and methane yield in the acceleration phase. It could be proved in a regression of these correlation values that the optimum treatment temperature is 164 °C and that the minimum treatment temperature should be above 115 °C. 相似文献