Mapping ground water vulnerability to pesticide leaching with a process-based metamodel of EuroPEARL

To support EU policy, indicators of pesticide leaching at the European level are required. For this reason, a metamodel of the spatially distributed European pesticide leaching model EuroPEARL was developed. EuroPEARL considers transient flow and solute transport and assumes Freundlich adsorption, first-order degradation and passive plant uptake of pesticides. Physical parameters are depth dependent while (bio)-chemical parameters are depth, temperature, and moisture dependent. The metamodel is based on an analytical expression that describes the mass fraction of pesticide leached. The metamodel ignores vertical parameter variations and assumes steady flow. The calibration dataset was generated with EuroPEARL and consisted of approximately 60,000 simulations done for 56 pesticides with different half-lives and partitioning coefficients. The target variable was the 80th percentile of the annual average leaching concentration at 1-m depth from a time series of 20 yr. The metamodel explains over 90% of the variation of the original model with only four independent spatial attributes. These parameters are available in European soil and climate databases, so that the calibrated metamodel could be applied to generate maps of the predicted leaching concentration in the European Union. Maps generated with the metamodel showed a good similarity with the maps obtained with EuroPEARL, which was confirmed by means of quantitative performance indicators.     

Forest carbon management in the United States: 1600-2100

This paper reviews the effects of past forest management on carbon stocks in the United States, and the challenges for managing forest carbon resources in the 21st century. Forests in the United States were in approximate carbon balance with the atmosphere from 1600-1800. Utilization and land clearing caused a large pulse of forest carbon emissions during the 19th century, followed by regrowth and net forest carbon sequestration in the 20th century. Recent data and knowledge of the general behavior of forests after disturbance suggest that the rate of forest carbon sequestration is declining. A goal of an additional 100 to 200 Tg C/yr of forest carbon sequestration is achievable, but would require investment in inventory and monitoring, development of technology and practices, and assistance for land managers.     

Application of two organic amendments on soil restoration: effects on the soil biological properties

One method for recovering degraded soils in semiarid regions is to add organic matter to improve soil characteristics, thereby enhancing biogeochemical nutrient cycling. In this paper, we studied the changes in soil biological properties as a result of adding a crushed cotton gin compost (CCGC) and a poultry manure (PM) for 4 yr to restore a Xerollic Calciorthid located near Seville (Guadalquivir Valley, Andalusia, Spain). Organic wastes were applied at rates of 5, 7.5, and 10 Mg organic matter ha(-1). One year after the assay began, spontaneous vegetation had appeared in the treated plots, particularly in that receiving a high PM and CCGC dose. After 4 yr, the plant cover in these treated plots was around 88 and 79%, respectively, compared with 5% for the control. The effects on soil microbial biomass and six soil enzymatic activities (dehydrogenase, urease, BBA-protease, beta-glucosidase, arylsulfatase, and alkaline phosphatase activities) were ascertained. Both added organic wastes had a positive effect on the biological properties of the soil, although at the end of the experimental period and at high dosage, soil microbial biomass and soil enzyme activities were generally higher in the PM-amended soils compared to the CCGC-amended soils. Enzyme activity from the PM-amended soil was 5, 15, 13, 19, 22, 30, and 6% greater than CCGC-amended soil for soil microbial biomass, urease, BBA-protease, beta-glucosidase, alkaline phosphatase, arylsulfatase, and dehydrogenase activities, respectively. After 4 yr, the percentage of plant cover was > 48% in all treated plots and 5% in the control.     

A comparative analysis of predictors of sense of place dimensions: attachment to, dependence on, and identification with lakeshore properties

Sense of place can be conceived as a multidimensional construct representing beliefs, emotions and behavioural commitments concerning a particular geographic setting. This view, grounded in attitude theory, can better reveal complex relationships between the experience of a place and attributes of that place than approaches that do not differentiate cognitive, affective and conative domains. Shoreline property owners (N=290) in northern Wisconsin were surveyed about their sense of place for their lakeshore properties. A predictive model comprising owners' age, length of ownership, participation in recreational activities, days spent on the property, extent of property development, and perceptions of environmental features, was employed to explain the variation in dimensions of sense of place. In general, the results supported a multidimensional approach to sense of place in a context where there were moderate to high correlations among the three place dimensions. Perceptions of environmental features were the biggest predictors of place dimensions, with owners' perceptions of lake importance varying in explanatory power across place dimensions.     

Framing of Geoengineering Affects Support for Climate Change Mitigation

The growing recognition that climate change mitigation alone will be inadequate has led scientists and policymakers to discuss climate geoengineering. An experiment with a US sample found, contrary to previous research, that reading about geoengineering did not reduce conservatives’ skepticism about the existence of anthropogenic climate change. Moreover, depending on how it is framed, geoengineering can reduce support for mitigation among both conservatives and non-conservatives. When geoengineering is framed as a major solution, people worry less about climate change, leading to reduced mitigation support. When framed as disastrous, people perceived geoengineering as riskier, also leading to a decrease in mitigation support. A more moderate framing of geoengineering as a partial solution is less susceptible to moral hazard effects. Overall, results suggest that geoengineering will not lessen political polarization over anthropogenic climate change, and could undercut support for mitigation efforts. Instead, framing geoengineering as a small piece to solving a big puzzle seems to be the best strategy to weaken this potential moral hazard.     

The Effect of Vaccinium vitis-idaea on Properties of Mountain-Meadow Soil under Alpine Lichen Heath

Russian Journal of Ecology - Abstract—The study of the effect of mycorrhiza symbiosis on the transformation of carbon and nitrogen compounds in soils is important in view of the necessity to...     

以膨润土为辅助添加剂固化/稳定化污泥的试验研究

针对传统以水泥固化污泥,带来的水泥用量大与固化体的浸出液pH过高等问题,提出了以膨润土为添加剂辅助水泥固化/稳定化污泥的思路.通过开展无侧限抗压强度试验、毒性浸出试验,测量掺入膨润土后污泥固化体的强度、重金属浸出率、浸出液COD及pH值,研究该固化/稳定化方法的效果.结果表明,膨润土的掺入极大地提高了固化体的抗压强度,将掺入量为0.4(相对污泥的质量比)的水泥一半用膨润土替代时,固化体的强度提高了6左右.体积安定性也能够满足要求.随膨润土掺入量增加,固化体中锌、铅的浸出率与浸出液的pH值呈现不断减小的趋势,锌与铅的浸出率分别由6.9%下降至0.25%,9.6%下降至5%,pH值由12.3下降至12.1.在强碱条件下及烘干或风干条件下,铜会随着有机物的分解而析出,从而增加铜的浸出率,而膨润土的加入能弥补水泥造成的强碱环境及风干或烘干过程对固化污泥中铜的稳定产生的不利影响.     

Statistical comparison and correlation of zinc and lead in estuarine sediments along the western coast of Mauritius

Cr, Zn and Pb were quantified using atomic absorption spectrometry (AAS) from urban and rural estuarine sediments collected along the western coast of Mauritius during the period July 2002-January 2003. The mean concentration of Cr (225.4 mg kg(-1)), Zn (107.0 mg kg(-1)) and Pb (27.0 mg kg(-1)) in sediments along the six estuaries can be considered below those from contaminated estuarine sediments. Zn and Pb were significantly higher in urban sediments downstream St. Louis River compared to a rural estuary at Tamarin at 5% significance level. Zn was also significantly lower in Tamarin compared to Petite Riviere Noire estuary. Cr was however not significantly different in sediments from the six estuaries and could be considered of basaltic origin and were correlated to neither lead nor zinc. The concentration of Zn and Pb were greatest in the more urbanised upper and lower reaches of the St. Louis estuary during the period of study and were also significantly positively correlated in the estuarine sediments indicating that the cycling of Pb and Zn were linked indicating a common source for Pb and Zn. The potential sources of Pb and Zn in the urban estuarine sediments were considered to arise from road runoff causing significant quantities to be trapped. At present, compared to contaminant levels found in the UK and elsewhere, Mauritius still looks relatively uncontaminated but there is growing concern about heavy metal contamination in urban estuaries. There is therefore a need for long-term studies in estuarine management to involve integrated strategies in which water-sediment interactions in estuaries need to be considered and international standards for sediment quality developed. Such studies undertaken in the future would further the understanding of the biogeochemical processes of estuarine systems in Mauritius which could then be used in environmental development schemes and effective coastal zone management.     

Thallium: a review of public health and environmental concerns

Thallium (Tl) is a rare but widely dispersed element. All forms of thallium are soluble enough to be toxic to living organisms. Thallium is more toxic to humans than mercury, cadmium, lead, copper or zinc and has been responsible for many accidental, occupational, deliberate, and therapeutic poisonings since its discovery in 1861. Its chemical behavior resembles the heavy metals (lead, gold and silver) on the one hand and the alkali metals (K, Rb, Cs) on the other. It occurs almost exclusively in natural waters as monovalent thallous cation. The solubility of thallous compounds is relatively high so that monovalent thallium is readily transported through aqueous routes into the environment. Tl can be transferred from soils to crops readily and accrues in food crops. The fascinating chemistry and high toxicity potential make thallium and its compounds of particular scientific interest and environmental concern. Thallium was detected in base-metal mining effluents. The conventional removal of heavy metals from wastewater has little effect on thallium. In this review, various treatment options and removal technologies are enumerated in order to protect the environment from thallium toxicity.