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Zetterberg T.,IVL Swedish Environmental Research Institute Ltd | Zetterberg T.,Swedish University of Agricultural Sciences | Olsson B.A.,Swedish University of Agricultural Sciences | Lofgren S.,Swedish University of Agricultural Sciences | And 2 more authors.
Forest Ecology and Management | Year: 2013

Removal of logging residues may lead to soil and surface water acidification by lowering the amount of buffering base cations. Long-term treatment differences in soil exchangeable calcium pools (down to 20cm) and soil solution calcium concentrations at 50cm soil depth were examined at three coniferous sites in Sweden following conventional and whole-tree harvesting in 1974-1976. Results from the statistical analysis (p<0.05) showed that soil water concentrations of calcium were 17μeql-1 (or 40%) lower in whole-tree harvested plots compared with conventional harvested plots, 27-30years after harvest. The main treatment differences had largely disappeared 32-35years after harvest although site specific treatment differences (δWTH-CH: -24μeql-1) were still measurable at the well-buffered site in northern Sweden. These results are in agreement with soil data showing that previously found treatment differences in calcium pools had diminished in the forest floor but remained in deeper soil layers (-0.29, -0.37 and -0.24kmolcha-1 in the 5-10, 10-15 and 15-20cm soil layer, respectively). The presence of an interaction effect in the 10-15cm soil layer indicates, however, that the treatment response on calcium pools is much less at the southern sites. These results indicate that the effect of WTH on soil and soil solution concentrations is temporary but site specific. Contrary to common beliefs, the greatest soil and soil water effect was observed at the well-buffered site where the loss of calcium during WTH is less likely to lead to acidification effects. The treatment effects on soil solution at the more acidic sites in southern Sweden were much smaller and probably not large enough to fully counterbalance the general recovery from acidification during the study period. © 2013 Elsevier B.V. Source


Lofgren S.,Swedish University of Agricultural Sciences | Zetterberg T.,IVL Swedish Environmental Research Institute Ltd
Science of the Total Environment | Year: 2011

During the last two decades, there is a common trend of increasing concentrations of dissolved organic carbon (DOC) in streams and lakes in Europe, Canada and the US. Different processes have been proposed to explain this trend and recently a unifying hypothesis was presented, concluding that declining sulphur deposition and recovery from acidification, is the single most important factor for the long-term DOC concentration trends in surface waters. If this recovery hypothesis is correct, the soil water DOC concentrations should increase as well. However, long-term soil water data from Sweden and Norway indicate that there are either decreasing or indifferent DOC concentrations, while positive DOC trends have been found in the Czech Republic. Based on the soil water data from two Swedish integrated monitoring sites and geochemical modelling, it has been shown that depending on changes in pH, ionic strength and soil Al pools, the DOC solubility might be positive, negative or indifferent. In this study, we test the acidification recovery hypothesis on long-term soil water data (25 and 50cm soil depth) from 68 forest covered sites in southern Sweden, showing clear signs of recovery from acidification. The main aim was to identify potential drivers for the DOC solubility in soil solution by comparing trends in DOC concentrations with observed changes in pH, ionic strength and concentrations of Aln+. As in earlier Swedish and Norwegian studies, the DOC concentrations in soil water decreased or showed no trend. The generally small increases in pH (median <0.3 pH units) during the investigation period seem to be counterbalanced by the reduced ionic strength and diminished Al concentrations, increasing the organic matter coagulation. Hence, opposite to the conclusion for surface waters, the solubility of organic matter seems to decrease in uphill soils, as a result of the acidification recovery. © 2011 Elsevier B.V. Source


Zetterberg T.,IVL Swedish Environmental Research Institute Ltd | Zetterberg T.,Swedish University of Agricultural Sciences
Science of the Total Environment | Year: 2014

Forest biofuel is a main provider of energy in Sweden and the market is expected to grow even further in the future. Removal of logging residues via harvest can lead to short-term acidification but the long-term effects are largely unknown. The objectives of this study were to 1) model the long-term effect of whole-tree harvest (WTH) on soil and stream water acidity and 2) perform sensitivity analyses by varying the amounts of logging residues, calcium (Ca2+) concentrations in tree biomass and site productivity in nine alternate scenarios. Data from three Swedish forested catchments and the Model of Acidification of Groundwater in Catchments (MAGIC) were used to simulate changes in forest soil exchangeable Ca2+ pools and stream water acid neutralizing capacity (ANC) at Gammtratten, Kindla and Aneboda. Large depletions in soil Ca2+ supply and a reversal of the positive trend in stream ANC were predicted for all three sites after WTH. However, the magnitude of impact on stream ANC varied depending on site and the concentration of mobile strong acid anions. Contrary to common beliefs, the largest decrease in modelled ANC was observed at the well-buffered site Gammtratten. The effects at Kindla and Aneboda were much more limited and not large enough to offset the general recovery from acidification. Varying the tree biomass Ca2+ concentrations exerted the largest impact on modelled outcome. Site productivity was the second most important variable whereas changing biomass amounts left on site only marginally affected the results. The outcome from the sensitivity analyses pointed in the same direction of change as in the base scenario, except for Kindla where soil Ca2+ pools were predicted to be replenished under a given set of input data. The reliability of modelled outcome would increase by using site-specific Ca2+ concentrations in tree biomass and field determined identification of site productivity. © 2014 Elsevier B.V. Source


Berglund A.M.M.,Umea University | Ingvarsson P.K.,Umea University | Danielsson H.,IVL Swedish Environmental Research Institute Ltd | Nyholm N.E.I.,Umea University
Environmental Pollution | Year: 2010

Mining activities affect the surrounding environment by increasing exposure to metals. In this study, metal accumulation and its effects on reproduction and health of pied flycatcher (Ficedula hypoleuca) nestlings were monitored before and up to five years after a lead mine and enrichment plant closed down. The lead concentration in moss, nestling blood, liver and feces all indicated decreased lead exposure by at least 31% after closure, although only blood lead decreased significantly. Although the birds responded fairly well to the changed atmospheric deposition (based on moss samples), concentrations were still higher compared with birds in a reference area, and breeding was affected at the mine (smaller clutches and higher mortality). Surviving nestlings suffered from lower hemoglobin levels, mean cell hemoglobin concentrations and inhibited δ-aminolevulinic acid dehydratase activity. Lead poisoning contributed to poor health and adverse reproductive effects, but other factors (e.g. increased parasitic load) probably also affected the birds. © 2010 Elsevier Ltd. All rights reserved. Source


Cousins A.P.,IVL Swedish Environmental Research Institute Ltd | Holmgren T.,Umea University | Remberger M.,National Defence Center
Science of the Total Environment | Year: 2014

Estimated emissions of decabrominated diphenyl ether (BDE 209) and the two phthalate esters diethylhexyl phthalate (DEHP) and diisononyl phthalate (DINP) to indoor air in the Stockholm conurbation, Sweden were used to assess the contribution of chemical outflows from the indoor environment to urban outdoor air pollution for these substances, by applying the recently developed Stockholm MUltimedia URban fate (SMURF) model. Emission rates of DINP from PVC materials were measured and published emission rates of DEHP were adapted to Swedish conditions. These were used as input to the model, as well as recently reported estimates of BDE 209 emissions to indoor air in Stockholm. Model predicted concentrations were compared to empirical monitoring data obtained from the literature and from additional measurements of phthalates in ventilation outlets and urban air performed in the current study. The predicted concentrations of the phthalates DINP and DEHP in indoor air and dust were within a factor of 1.5-10 of the measured concentrations. For BDE 209, predicted indoor concentrations were within the measured ranges, but measured concentrations showed a much larger variability. An adjusted emission scenario to better fit observed concentrations indoors was employed for DEHP and final outcomes resulted in estimated indoor emissions of 250 (50-1250), 2.9 (0.58-15), and 0.068 (0.014-0.34) kg year-1 for DEHP, DINP and BDE 209. These emissions could not explain the observed concentrations in urban air of the phthalates, suggesting an underestimation of background inflow or existence of additional sources in the outdoor environment. For BDE 209, the assessment indicates that the Stockholm indoor environment contributes about 25% to the air pollution load in inflowing background air, but additional monitoring data in urban air are needed to confirm this conclusion. © 2013 Elsevier B.V. Source

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