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Li J.,Southwest University | Li J.,Chongqing Water Resources and Electrical Engineering College | Sommar J.,Gothenburg University | Fang Z.,Southwest University | And 4 more authors.
Disaster Advances | Year: 2010

Total gaseous mercury (TGM) was carried out at six residential areas in Göteborg, Sweden by using Tekran 2537A Mercury Vapor Analyzer. TGM concentration in residential areas (2.89±1.44 ng m ) was 1.8 times than this in Rörvik (1.63±0.19 ng m-3) which clearly revealed the enhancement of anthropogenic source processes in residential areas. TGM concentration clearly indicated the pattern for an enhanced Hg concentration during nighttime relative to daytime in urban, while reverse diurnal pattern was observed in suburb, and rural area lagged behind the suburb. The elevated TGM in urban with lower wind was suggestive of a factor describing photochemistry in combination with local mobile sources. For suburb, the increased TGM was closely tied with the influence of coal combustion which came predominantly from the EES wind sector. As for rural, increased TGM may likely be the synthetic effects originated from suburb, urban and higher industrialized regions. Source


Pleijel H.,Gothenburg University | Danielsson H.,Swedish Environmental Research Institute Ltd. | Simpson D.,Norwegian Meteorological Institute | Simpson D.,Chalmers University of Technology | Mills G.,UK Center for Ecology and Hydrology
Biogeosciences | Year: 2014

Elevated levels of tropospheric ozone can significantly impair the growth of crops. The reduced removal of CO2by plants leads to higher atmospheric concentrations of CO2, enhancing radiative forcing. Ozone effects on economic yield, e.g. the grain yield of wheat (Triticum aestivum L.), are currently used to model effects on radiative forcing. However, changes in grain yield do not necessarily reflect changes in total biomass. Based on an analysis of 22 ozone exposure experiments with field-grown wheat, we investigated whether the use of effects on grain yield as a proxy for effects on biomass under- or overestimates effects on biomass. First, we confirmed that effects on partitioning and biomass loss are both of significant importance for wheat yield loss. Then we derived ozone dose response functions for biomass loss and for harvest index (the proportion of above-ground biomass converted to grain) based on 12 experiments and recently developed ozone uptake modelling for wheat. Finally, we used a European-scale chemical transport model (EMEP MSC-West) to assess the effect of ozone on biomass (-9%) and grain yield (-14%) loss over Europe. Based on yield data per grid square, we estimated above-ground biomass losses due to ozone in 2000 in Europe, totalling 22.2 million tonnes. Incorrectly applying the grain yield response function to model effects on biomass instead of the biomass response function of this paper would have indicated total above-ground biomass losses totalling 38.1 million (i.e. overestimating effects by 15.9 million tonnes). A key conclusion from our study is that future assessments of ozone-induced loss of agroecosystem carbon storage should use response functions for biomass, such as that provided in this paper, not grain yield, to avoid overestimation of the indirect radiative forcing from ozone effects on crop biomass accumulation. © 2014 Author(s). Source


Hellsten S.,Swedish Environmental Research Institute Ltd. | Helmisaari H.-S.,University of Helsinki | Melin Y.,Swedish University of Agricultural Sciences | Skovsgaard J.P.,Swedish University of Agricultural Sciences | And 5 more authors.
Forest Ecology and Management | Year: 2013

The objective of this study was to evaluate the concentrations of nutrients in stumps and coarse roots in Norway spruce, Scots pine and silver birch in Sweden, Finland and Denmark, and to assess how nutrient concentrations vary with site characteristics, stand age and root size. Concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg) and sodium (Na) in spruce, pine and birch stumps were assessed in eight sites across Scandinavia. Nutrient concentrations were higher in birch than in spruce and pine. In Sweden and Finland, the nutrient concentrations were generally higher at the southern sites than at the sites located in the northern part of the countries, except for P. For all nutrients, concentrations were significantly higher in the bark of the stump and roots than in the wood. Furthermore, nutrient concentrations increased significantly with decreasing root diameter. This study did not demonstrate any correlations with stand age. Further studies are needed to provide a broader picture of how the stump nutrient contents vary with site characteristics and forest management practices to provide a better foundation for nutrient balance calculations when setting up recommendations for stump removal. © 2012 Elsevier B.V. Source


Fischer A.,Gothenburg University | Ljungstrom E.,Gothenburg University | Hagerhed Engman L.,SP Technical Research Institute of Sweden | Langer S.,SP Technical Research Institute of Sweden | Langer S.,Swedish Environmental Research Institute Ltd.
Indoor Air | Year: 2015

Particle mass and number concentrations were measured in a mechanically ventilated classroom as part of a study of ventilation strategies for energy conservation. The ventilation system was operated either continuously, intermittently, or shut down during nights while it was on during workdays. It appears that the nighttime ventilation scheme is not important for indoor particle concentrations the following day if fans are operated to give five air exchanges in advance of the workday. The highest concentrations of PM10 were found during and after workdays and were due to human activity in the classroom. The average workday PM10 concentration was 14 μg/m3, well below the WHO guideline values. The number concentration of particles with diameter <0.750 μm was typically between 0.5 × 103 and 3.5 × 103 particle/cm3. These concentrations were largely independent of the occupants. Transient formation of small particles was observed when ventilation was shut down. Then remaining ozone reacted with terpenes emitted by indoor sources and gave up to 8 × 103 particle/cm3 before formation stopped due to lack of ozone. The intermittent ventilation regime was found least favorable for the indoor air quality in the classroom. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd. Source


Paulrud S.,Swedish Environmental Research Institute Ltd. | Paulrud S.,SP Technical Research Institute of Sweden | Laitila T.,Orebro University
Biomass and Bioenergy | Year: 2010

The present study adapts the choice experiment (CE) method for an analysis of how Swedish farmers assess the relative value of the characteristics associated with growing energy crops. An additional goal was to find out the willingness of farmers to grow energy crops relative to different levels of income and subsidies based on predictions of acreage of energy crop cultivation. In the first CE, farmers were presented with two energy crops and six of their characteristics and asked to choose the alternative he or she preferred most. In the second CE the respondent was asked how many hectares for each crop he/she would be willing to grow on arable land with an energy crop subsidy and how many hectares he/she would be willing to grow on set-aside land without an energy crop subsidy. The results suggest that among the included characteristics in the first experiment, the visual impact on the landscape and the rotation period of the energy crop appear to have a significant impact on the utility derived from growing an energy crop. An increased utility of a crop increases the arable land used for that crop and the income associated with it. Farm characteristics such as leased land, rented land, share of set-aside land, and type of farming had an insignificant effect on the willingness to grow energy crops. Significant characteristics were age of the farmer, size of the farm, and the geographical area. © 2010 Elsevier Ltd. Source

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