| 1. |
- Finlay, Roger, et al.
(författare)
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The role of fungi in biogenic weathering in boreal forest soils
- 2009
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Ingår i: Fungal Biology Reviews. - : Elsevier. - 1749-4613 .- 1878-0253. ; 23:4, s. 101-106
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Tidskriftsartikel (refereegranskat)abstract
- In this article we discuss the possible significance of biological processes, and of fungi in particular, in weathering of minerals. We consider biological activity to be a significant driver of mineral weathering in forest ecosystems. In these environments fungi play key roles in organic matter decomposition, uptake, transfer and cycling of organic and inorganic nutrients, biogenic mineral formation, as well as transformation and accumulation of metals. The ability of lichens, mutualistic symbioses between fungi and photobionts such as algae or cyanobacteria, to weather minerals is well documented. The role of mycorrhizal fungi forming symbioses with forest trees is less well understood, but the mineral horizons of boreal forests are intensively colonised by mycorrhizal mycelia which transfer protons and organic metabolites derived from plant photosynthates to mineral surfaces, resulting in mineral dissolution and mobilisation and redistribution of anionic nutrients and metal cations. The mycorrhizal mycelia, in turn provide efficient systems for the uptake and direct transport of mobilised essential nutrients to their host plants which are large sinks. Since almost all (99.99. %) non-suberised lateral plant roots involved in nutrient uptake are covered by ectomycorrhizal fungi, most of this exchange of metabolites must take place through the plant-fungus interface. This idea is still consistent with a linear relationship between soil mineral surface area and weathering rate since the mycelia that emanate from the tree roots will have a larger area of contact with minerals if the mineral surface area is higher. Although empirical models based on bulk soil solution chemistry may fit field data, we argue that biological processes make an important contribution to mineral weathering and that a more detailed mechanistic understanding of these must be developed in order to predict responses to environmental changes and anthropogenic impact. © 2010 The British Mycological Society.
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| 2. |
- Rämö, Robert, et al.
(författare)
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Sediment Remediation Using Activated Carbon: Effects of Sorbent Particle Size and Resuspension on Sequestration of Metals and Organic Contaminants.
- 2022
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Ingår i: Environmental toxicology and chemistry. - : Wiley. - 1552-8618 .- 0730-7268. ; 41:4, s. 1096-1110
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Tidskriftsartikel (refereegranskat)abstract
- Thin-layer capping using activated carbon (AC) has been described as a cost-effective in situ sediment remediation method for organic contaminants. In this study, we compare the capping efficiency of powdered AC (PAC) against granular AC (GAC) using contaminated sediment from Oskarshamn harbor, Sweden. The effects of resuspension on contaminant retention and cap integrity were also studied. Intact sediment cores were collected from the outer harbor and brought to the laboratory. Three thin-layer caps, consisting of PAC or GAC mixed with clay, or clay only, were added to the sediment surface. Resuspension was created using a motor-driven paddle to simulate propeller wash from ship traffic. Passive samplers were placed in the sediment and in the water column to measure the sediment-to-water release of PAHs, PCBs, and metals. Our results show that a thin-layer cap with PAC reduced sediment-to-water fluxes of PCBs by 57 % under static conditions and 91 % under resuspension. Thin-layer capping with GAC was less effective than PAC, but reduced fluxes of high-molecular weight PAHs. Thin-layer capping with AC was less effective in retaining metals, except for Cd, which release was significantly reduced by PAC. Resuspension generally decreased water concentrations of dissolved cationic metals, perhaps due to sorption to suspended sediment particles. Sediment resuspension in treatments without capping increased fluxes of PCBs with log Kow > 7 and PAHs with log Kow 5 6, but resuspension reduced PCB and PAH fluxes through the PAC thin-layer cap. Overall, PAC performed better than GAC, but adverse effects on the benthic community and transport of PAC to non-target areas are drawbacks that favor the use of GAC. This article is protected by copyright. All rights reserved.© 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
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| 3. |
- Beier, Ulrika, et al.
(författare)
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Fisk och fiske i Mälaren
- 2015
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Rapport (populärvet., debatt m.m.)abstract
- Nära en tredjedel av Sveriges befolkning bor i Mälardalen. Mälaren är Sveriges tredje största sjö och en av de artrikaste beträffande fisk. Sjön är både flikig och mångsidig. Ömsom kantas den av slätter med intensivt jordbruk och stora vassområden, ömsom av karga klippor och grusstränder. Här finns omväxlande små och stora öar, grunda vikar, trånga sund och stora, djupa fjärdar. Mälaren har förorenats under århundraden och är fortfarande delvis övergödd. Trots det tjänar den som landets största dricksvattentäkt. Två miljoner människor får dricksvatten från Mälaren. Länge har fokus varit på sjöns vattenkvalitet, både för att dricka och bada i. Mälaren är också viktig som fiskesjö. Fiske i Mälaren innebär oftast rekreation men sjön försörjer också cirka trettio yrkesfiskare. Sist men inte minst - fisken i Mälaren är en viktig del i dess ekosystem. Genom näringsväven återkopplar fisken oundvikligen till vattnets kvalitet. I den här rapporten vill vi sätta Mälarens fisk i fokus. Vi ska berätta om fiskarter som är viktiga för ekosystemet och fisket samt om hur fisken i Mälaren undersöks.
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| 4. |
- Kylin, Henrik, et al.
(författare)
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Evaluating threats to an endangered species by proxy : air pollution as threat to the blue swallow (Hirundo atrocaerulea) in South Africa
- 2011
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Ingår i: Environmental Science and Pollution Research. - : Springer. - 0944-1344 .- 1614-7499. ; 18:2, s. 282-290
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Tidskriftsartikel (refereegranskat)abstract
- Background, aim, and scope: The blue swallow (Hirundo atrocaerulea) is one of the most threatened bird species in southern Africa. Among terrestrial birds, its plumage is known to be the most water repellent, an adaptation to foraging on the wing in dense fog. Despite this uniqueadaptation, the nesting success of the blue swallow at the Blue Swallow Natural Heritage Site (BSNHS) is lower during years with high incidence of fog. As the phenomenon is not observed at other nesting sites, we hypothesized that this is due to changes in the air chemistry at the BSNHS. In the immediate proximity of the BSNHS, plantations of exotic trees (e.g., pines and eucalypts), rich in volatile organic compounds (VOCs), are dominant features. In addition, air pollution from the Johannesburg area is transported with the surface winds and mix withVOCs released from exotic trees. Together with the high humidity and high elevation, these conditions may result in the formation of sulphonates. Sulphonates are strong detergents, and the presence of these in the fog could lead to decreased water repellence of the plumage. This study was performed in order to determine the occurrence and distribution of sulphonates in the BSNHS and to compare these with sulphonates formed in other locations in South Africa. Because the blue swallow is endangered, pine needles were used as proxy to detect formation of sulphonates.Methods: We sampled pine needles with different exposure to air pollutants, in climates with different humidity, and at different elevation and analyzed these for sulphonates using mass spectrometry.Results: Pine needles from high elevations and the BSNHS, with high humidity, and exposure to air pollution contained significantly higher concentrations of sulphonates than pine needles from low elevations or from high elevations with a dryer climate or a different combination of air pollutants.Conclusions: These findings lead to two conclusions. First, the occurrence and distribution of sulphonates may be explained by chemical reactions between sulphur dioxide and organic compounds in the humid air induced by ultraviolet radiation. Second, elevated concentrations of sulphonates in the fog could affect the water repellence of the blue swallow plumage, possibly decreasing their capacity to forage in the fog. We cannot prove conclusively that this is the reason why the number of blue swallows atthe BSNHS has decreased dramatically, but for endangered species, we may have to rely on proxies to draw conclusions about outside threats. All such information should be valuable in devising protection plans for species under threat.Recommendations and perspectives: The use of proxies to elucidate threats to endangered species should be evaluated in a broad scale. The mist-belt habitat in general is threatened by many human activities. These findings indicate that air pollution and the proximity of volatile organic compound (VOC) sources close to mist-belt habitat refuges may be an unrecognised conservation threat to the animals inhabiting them.
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| 5. |
- Johansson, Emma M., et al.
(författare)
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Quantitative analysis of soluble exudates produced by ectomycorrhizal roots as a response to ambient and elevated CO2
- 2009
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Ingår i: Soil Biology and Biochemistry. - Amsterdam : Elsevier. - 0038-0717 .- 1879-3428. ; 41:6, s. 1111-1116
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Tidskriftsartikel (refereegranskat)abstract
- Despite its potential impact on soil carbon flow, few studies have attempted to quantify the effects of elevated carbon dioxide (CO2) on production of exudates by mycorrhizal plants. In this study we quantified low molecular weight (LMW) organic compounds exuded by non-mycorrhizal (NM) and ectomycorrhizal (ECM) plants in relation to exposure to elevated CO2. Scots pine seedlings, either colonized by one of eight different ECM fungi or non-mycorrhizal (NM), were exposed to either ambient (350 ppm) or elevated (700 ppm) concentrations of CO2. Exudation of LMW organic acids (LMWOAs), amino acids, dissolved monosaccharides and total dissolved organic carbon (DOC) was determined and exudation rates were calculated per g root and fungal dry mass. CO2 had a significant impact on exudation. Under elevated CO2, exudation of total LMWOAs increased by 120–160%, amino acids by 250%, dissolved monosaccharides by 130–270% and DOC by 180–220% compared to ambient CO2 treatment. Net CO2 assimilation rates increased significantly by 41–47% for seedlings exposed to elevated CO2. Exuded C calculated as a percentage of assimilated CO2 increased by 41–88% in the elevated CO2 treatment compared to ambient CO2 treatment.
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| 6. |
- Hyvonen, R., et al.
(författare)
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The likely impact of elevated [CO2], nitrogen deposition, increased temperature and management on carbon sequestration in temperate and boreal forest ecosystems: a literature review
- 2007
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Ingår i: New Phytologist. - Cambridge : Wiley. - 0028-646X .- 1469-8137. ; 173:3, s. 463-480
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Forskningsöversikt (refereegranskat)abstract
- Temperate and boreal forest ecosystems contain a large part of the carbon stored on land, in the form of both biomass and soil organic matter. Increasing atmospheric [CO2], increasing temperature, elevated nitrogen deposition and intensified management will change this C store. Well documented single-factor responses of net primary production are: higher photosynthetic rate (the main [CO2] response); increasing length of growing season (the main temperature response); and higher leaf-area index (the main N deposition and partly [CO2] response). Soil organic matter will increase with increasing litter input, although priming may decrease the soil C stock initially, but litter quality effects should be minimal (response to [CO2], N deposition, and temperature); will decrease because of increasing temperature; and will increase because of retardation of decomposition with N deposition, although the rate of decomposition of high-quality litter can be increased and that of low-quality litter decreased. Single-factor responses can be misleading because of interactions between factors, in particular those between N and other factors, and indirect effects such as increased N availability from temperature-induced decomposition. In the long term the strength of feedbacks, for example the increasing demand for N from increased growth, will dominate over short-term responses to single factors. However, management has considerable potential for controlling the C store.
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| 7. |
- Cucarella Cabañas, Victor
(författare)
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Recycling Filter Substrates used for Phosphorus Removal from Wastewater as Soil Amendments
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis studied the viability of recycling filter substrates as soil amendments after being used in on-site systems for phosphorus (P) removal from wastewater. Focus was put on the materials Filtra P and Polonite, which are commercial products used in compact filters in Sweden. A prerequisite for this choice was to review filter materials and P sorption capacity. The filter substrates (Filtra P, Polonite and wollastonite tailings) were recycled from laboratory infiltration columns as soil amendments to a neutral agricultural soil and to an acid meadow soil to study their impacts on soil properties and yield of barley and ryegrass. The amendments tended to improve the yield and showed a liming effect, significantly increasing soil pH and the availability of P. In another experiment, samples of Filtra P and Polonite were equilibrated in batch experiments with the two soils in order to study the P dynamics in the soil-substrate system. Batch equilibrations confirmed the liming potential of Filtra P and Polonite and showed that improved P availability in soils was strongly dependent on substrate P concentration, phase of sorbed P, and soil type. Finally, samples of Polonite used for household wastewater treatment were recycled as soil amendments to a mountain meadow and to an agricultural field for wheat cropping. The liming effect of Polonite was confirmed under field conditions and the results were similar to those of lime for the mountain meadow soil. However, the results were quite different for the agricultural field, where Polonite did not affect soil pH or any other chemical and physical soil properties investigated and had no impact on wheat yield and quality. The results from field experiments suggested that Polonite can be safely recycled to meadows and cropping fields at rates of 5-10 ton ha-1 but long-term studies are needed to forecast the effects of accumulation.
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| 8. |
- Norrgran, Jessica, et al.
(författare)
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Decabromobiphenyl, Polybrominated Diphenyl Ethers, and Brominated Phenolic Compounds in Serum of Cats Diagnosed With the Endocrine Disease Feline Hyperthyroidism
- 2012
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Ingår i: Archives of Environmental Contamination and Toxicology. - : Springer Science and Business Media LLC. - 0090-4341 .- 1432-0703. ; 63:1, s. 161-168
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Tidskriftsartikel (refereegranskat)abstract
- The incidence of cats being diagnosed with feline hyperthyroidism (FH) has increased greatly since it was first described in 1979. The cause of FH has not been established. Hypothetically, there is a link between increasing FH and exposure to brominated flame retardants. Much greater polybrominated diphenyl ethers (PBDE) concentrations have been reported in cat serum compared with human serum, likely due to cat licking behaviour. This study aimed to extend the present identification of brominated compounds in cat serum, with a focus on hydroxylated metabolites of PBDE, to improve the understanding of feline metabolism of PBDEs. A pooled serum sample from 30 Swedish pet cats with FH was analysed, and brominated species were identified. The results showed exposure to the discontinued flame retardant decabromobiphenyl (BB-209) and technical penta- and octa-BDEs. Altogether 12 PBDE congeners were identified along with 2'-MeO-BDE68. Furthermore, 2,4-dibromophenol, 2,4,6-, 2,4,5- and 2,3,4-tribromophenol plus 2'-OH-BDE68, 6-OH-BDE47, 5-OH-BDE47, 4'-OH-BDE49 were identified. 2,4,6-tribromophenol and 6-OH-BDE47 were the most prominent species in cat serum. Considering that these are natural products, it can be concluded that metabolism of PBDEs to OH-PBDEs is not a major route of PBDE elimination in cats. It is notable that BB-209, 6-OH-BDE47, and 2,4,6-tribromophenol all suggested that endocrine-disrupting chemicals were present in high concentrations in cat serum.
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| 9. |
- Garemark, Jonas, et al.
(författare)
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Advancing Hydrovoltaic Energy Harvesting from Wood through Cell Wall Nanoengineering
- 2023
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Ingår i: Advanced Functional Materials. - : John Wiley and Sons Inc. - 1616-301X .- 1616-3028. ; 33:4
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Tidskriftsartikel (refereegranskat)abstract
- Converting omnipresent environmental energy through the assistance of spontaneous water evaporation is an emerging technology for sustainable energy systems. Developing bio-based hydrovoltaic materials further pushes the sustainability, where wood is a prospect due to its native hydrophilic and anisotropic structure. However, current wood-based water evaporation-assisted power generators are facing the challenge of low power density. Here, an efficient hydrovoltaic wood power generator is reported based on wood cell wall nanoengineering. A highly porous wood with cellulosic network filling the lumen is fabricated through a green, one-step treatment using sodium hydroxide to maximize the wood surface area, introduce chemical functionality, and enhance the cell wall permeability of water. An open-circuit potential of ≈140 mV in deionized water is realized, over ten times higher than native wood. Further tuning the pH difference between wood and water, due to an ion concentration gradient, a potential up to 1 V and a remarkable power output of 1.35 µW cm−2 is achieved. The findings in this study provide a new strategy for efficient wood power generators. © 2022 The Authors.
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| 10. |
- Brun, Christian, et al.
(författare)
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Spatial distribution of major, trace and ultra trace elements in three Norway spruce (Picea abies) stands in boreal forests, Forsmark, Sweden
- 2010
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Ingår i: Geoderma. - : Elsevier BV. - 0016-7061 .- 1872-6259. ; 159:3-4, s. 252-261
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Tidskriftsartikel (refereegranskat)abstract
- The spatial distribution of 49 major, trace and ultra trace elements within a Norway spruce system was examined in three sites within the Forsmark area in central Sweden. The system included stemwood, roots, fresh green shoots, litterbags, humus, mineral soil, rhizosphere soil and moss. Based on Principal Component Analysis and manual plots the elements were grouped according to their distribution within the different compartments. One large group of elements occurring abundantly in the soil, and in much lower concentrations in the biota and litter was distinguished, containing mainly elements typically associated with soil minerals. A similar pattern was found for a second group of elements, but with higher concentrations in the biological samples and/or litter. In contrast, there was also one group of elements with high concentrations in biological samples and/or litter and low content in soil. This was mainly nutrients, but also the highly toxic Cd, Hg and Sb. This study is part of the site investigation programme, carried out by the Swedish Nuclear Fuel and Waste Management Company (SKB), in order to locate a suitable area for a deep repository for nuclear fuel waste.
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