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  • 1. Ahonen-Jonnarth, U.
    et al.
    Van Hees, P.A.W.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Finlay, R.D.
    Organic acids produced by mycorrhizal Pinus sylvestris exposed to elevated aluminium and heavy metals concentrations2000In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 146, no 3, p. 557-567Article in journal (Refereed)
    Abstract [en]

    A cultivation method was developed to enable exposure of ectomycorrhizal plants with intact extramatrical mycelium to solutions containing different concentrations of aluminium or heavy metals. Pinus sylvestris seedlings colonized by Suillus variegatus (two isolates), Rhizopogon roseolus or Paxillus involutus (two isolates) were used. Seedlings were transferred to Petri dishes containing glass beads and exposed to elevated concentrations of Al, Cd, Cu, or Ni in two ways: immediately following transfer; and after allowing mycorrhizal seedlings to develop an extraradical mycelium that colonized the interface between the upper surface of the beads and the metal-containing solution. Production of organic acids in mycorrhizal and non-mycorrhizal systems was measured by withdrawing samples from the solution and analyzing by HPLC. In most experiments, levels of oxalic acid were significantly higher in mycorrhizal treatments than in non-mycorrhizal controls. The measured levels of organic acids were variable, but the results obtained suggest that production of oxalic acid is stimulated by exposure to elevated Al in mycorrhizal seedlings colonized by S. variegatus and R. roseolus. Elevated Al concentrations also increased oxalic acid production by non-mycorrhizal seedlings significantly in two of four Al experiments performed, but the measured concentrations were significantly lower than in corresponding mycorrhizal treatments in both cases. Malonic acid was found in the culture solution of non-mycorrhizal had P. involutus-colonized seedlings, but only trace amounts were found in S. variegatus or R. roseolus-infected seedlings. Citric, shikimic, lactic, acetic, propionic, fumaric, formic, iso-butyric and butyric acid were found in variable concentrations. Production of oxalic acid by seedlings ColoniZed by S. variegatus BL or P. involutus was not stimulated by exposure to 0.44 μM Cd or 17 μM Ni. Exposure to 0.157 mM CU in two separate experiments using P. involutus 87.017 and two strains of S. variegatus (BL and 159) appeared to stimulate production of oxalic acid irrespective of mycorrhizal status or species.

  • 2.
    Ali, Tara
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Essén, Sofia A.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Liquid extraction of low molecular mass organic acids and hydroxamate siderophores from boreal forest soil2011In: Soil Biology and Biochemistry, ISSN 0038-0717, E-ISSN 1879-3428, Vol. 43, no 12, p. 2417-2422Article in journal (Refereed)
    Abstract [en]

    Low molecular mass organic acids (LMMOAs) and hydroxamate siderophores (HS) are molecules secreted by microbes and have previously been found in soil solution and in cultures. Mycorrhizal fungi are suggested to be involved in the nutrient uptake processes of trees and weathering of minerals. In this study soil samples taken from the O and E horizons of a podzol were extracted with 10 mM potassium phosphate buffer at pH 7.2. Variable parameters included addition of methanol to the extraction buffer and the use of ultrasonication or rotary shaking during extraction. LMMOAs and HS content of the soil extracts were determined. Analysis of soil extracts were carried out by liquid chromatography mass spectrometry (LC-MS) and the extraction results compared to results for soil solution samples obtained by centrifugation of the soils sampled. The extraction yields were significantly increased by addition of methanol to the extraction buffer, especially for the O horizon samples. Rotary shaking of the samples for 90 min gave slightly higher yields than ultrasonication for 15 min but the reduction in extraction time makes ultrasonication an attractive option. Of the HSs determined, ferricrocin was found in all samples. Optimal extraction conditions showed citric acid and isocitric acid to be the most abundant organic acids in the O and E horizons, respectively.

  • 3. Bergelin, A.
    et al.
    van Hees, P. A. W.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Wahlberg, O.
    Department of Chemistry, Royal Institute of Technology, .
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    The acid-base properties of high and low molecular weight organic acids in soil solutions of podzolic soils2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 2-4, p. 223-235Article in journal (Refereed)
    Abstract [en]

    The acid properties of the organic acids and identified low molecular weight (LMW) organic acids in soil solutions of podzolic soils were determined using proton affinity spectra, based on EMF titration data, and Gran titrations. The proton affinity spectra showed apparent pKa values of 2.6, 4.1, 5.4 and 6.7 for the dissolved organic material. The LMW organic acids had similar pKa values. The average specific buffer capacity as determined by Gran titrations was 8.8±0.5 μmol H+/mg DOC. The specific buffer capacity for the identified low molecular acids was 40±2 μmol H+/mg DOC.

  • 4.
    Bylund, Dan
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norström, Sara
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Essén, Sofia
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Analysis of low molecular mass organic acids in natural waters by ion exclusion chromatography tandem mass spectrometry2007In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1176, no 1-2, p. 89-93Article in journal (Refereed)
    Abstract [en]

    A sensitive and selective method for the analysis of aliphatic low molecular mass organic acids (LMMOAs) in natural waters is presented. The method is based on separation with ion exclusion chromatography and detection with electrospray ionization tandem mass spectrometry (LC-MS/MS). The extra selectivity gained by applying MS/MS allows for a minimum of sample preparation and the use of a sub-optimal mobile phase regarding chromatographic resolution. Instead the mobile phase, comprising aqueous formic acid With methanol as organic modifier, was mainly optimized for maximum sensitivity and long term MS stability. Detection limits for malonic, fumaric, maleic, succinic, citraconic, glutaric, malic, alpha-ketoglutaric, tartaric, shikimic, trans-aconitic, cis-aconitic, isocitric and citric acid were in the range 1-50 nM, while the detection limits for pyruvic, oxalic and lactic acid were around 250 nM for an injection volume of 100 mu L. Due to their metal-chelating properties, these LMMOAs are all considered to affect the bioavailability of metals and to be involved in soil forming processes. It is thus of interest to be able to monitor their presence in natural waters, and the method developed within this work was successfully applied for the analysis of LMMOAs in soil solution and stream water samples.

  • 5.
    Dijkstra, F. A.
    et al.
    Laboratory of Soil Science and Geology, PO Box 37, 6700 AA Wageningen, PAYS-BAS.
    Geibe, Christine
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Holmström, Sara
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    van Breemen, N.
    Laboratory of Soil Science and Geology, PO Box 37, 6700 AA Wageningen, PAYS-BAS.
    The effect of organic acids on base cation leaching from forest floor under six north American tree species2001In: European Journal of Soil Science, ISSN 1351-0754, E-ISSN 1365-2389, Vol. 52, no 2, p. 205-214Article in journal (Refereed)
    Abstract [en]

    Organic acidity and its degree of neutralization in the forest floor can have large consequences for base cation leaching under different tree species. We investigated the effect of organic acids on base cation leaching from the forest floor under six common North American tree species. Forest floor samples were analysed for exchangeable cations and forest floor solutions for cations, anions, simple organic acids and acidic properties. Citric and lactic acid were the most common of the acids under all species. Malonic acid was found mainly under Tsuga canadensis (hemlock) and Fagus grandifolia (beech). The organic acids were positively correlated with dissolved organic carbon and contributed significantly to the organic acidity of the solution (up to 26%). Forest floor solutions under Tsuga canadensis contained the most dissolved C and the most weak acidity among the six tree species. Under Tsuga canadensis we also found significant amounts of strong acidity caused by deposition of sulphuric acid from the atmosphere and by strong organic acids. Base cation exchange was the most important mechanism by which acidity was neutralized. Organic acids in solution from Tsuga canadensis, Fagus grandifolia, Acer rubrum (red maple) and Quercus rubra (red oak) were hardly neutralized while much more organic acidity was neutralized for Acer saccharum (sugar maple) and Fraxinus americana (white ash). We conclude that quantity, nature and degree of neutralization of organic acids differ among the different tree species. While the potential for base cation leaching with organic acids from the forest floor is greatest under Tsuga canadensis, actual leaching with organic anions is greatest under Acer saccharum and Fraxinus americana under which the forest floor contains more exchangeable cations than does the strongly acidified forest floor under Tsuga canadensis.

  • 6.
    Essén, Sofia
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Holmström, Sara
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Moberg, M
    Uppsala University.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Quantification of hydroxamate siderophores in soil solutions of podzolic soil profiles in Sweden2006In: Biometals, ISSN 0966-0844, E-ISSN 1572-8773, Vol. 19, no 3, p. 269-282Article in journal (Refereed)
    Abstract [en]

    Concentrations up to 2 and 12 nM of the hydroxamate siderophores ferrichrome and ferricrocin, respectively, were identified in soil solutions of podzolic forest soils at four sites in both northern and southern Sweden. No ferrichrysin was detected. As with the dissolved organic carbon and low molecular mass organic acids, the highest concentrations of the siderophores were found in the upper layers i.e. the mor layer, the eluvial and upper illuvial horizons. At the southern sites, the concentrations of ferrichrome and ferricrocin were both of similar magnitude and did not differ between the two sites. In contrast, soil solutions at the two northern sites contained more ferricrocin than ferrichrome; the ferricrocin concentrations were also higher at the northern sites than at the southern sites. Analyses were performed by high performance liquid chromatography with a porous graphitic carbon column on which ferrichrome, ferricrocin and ferrichrysin were separated. Detection by electrospray ionization mass spectrometry (ESI-MS) combined with on-line sample pre-concentration, by means of column-switching, enabled detection limits of 0.1-0.2 nM for ferrichrome, ferrichrysin and ferricrocin. The structural identities of the siderophores were further verified by MS/MS fragmentation. Fragmentation of ferrichrome, ferricrocin and ferrichrysin occured mainly via peptide cleavage. The most intense fragments were typified by the loss of one of the three iron(III) chelating hydroxamate residues, i.e N5-acyl-N5-hydroxy ornithine.

  • 7.
    Essén, Sofia
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Walve, J
    Ingri, J
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Quantification of hydroxamate siderophores in the Baltic Sea and cyanobacterial populations by capillary LC-ESI-MS/MSManuscript (Other (popular science, discussion, etc.))
  • 8.
    Essén, Sofia
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Johnson, Anna
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Pedersen, Karsten
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Siderophore production by Pseudomonas stutzeri under aerobic and anaerobic conditions2007In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 73, no 18, p. 5857-5864Article in journal (Refereed)
  • 9.
    Geibe, Christine
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Danielsson, Rolf
    Uppsala University.
    van Hees, Patrick A.W
    Örebro University.
    Lundström, Ulla. S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Comparison of soil solution chemistry sampled by centrifugation, two types of suction lysimeters and zero-tension lysimeters2006In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 21, no 12, p. 2096-2111Article in journal (Refereed)
    Abstract [en]

    The choice of sampling method for soil solution is of great importance. In this paper soil solution chemistry sampled by centrifugation, two types of suction lysimeters and zero-tension lysimeters have been studied with the purpose of investigating systematic differences between them. The samples were taken at 4 depths from an acidified forest soil as well as from adjacent lime and ash treated soils. A centrifugation drainage method was compared with two types of suction lysimeters (‘Rhizon’ and ‘Prenart’) and zero-tension lysimeters. About half of the 27 variables measured showed a significant difference between the sampling methods used. Typically the centrifuged samples had lower pH (4.0 vs. 4.4), Ca (21 lM vs. 30 lM) and Mg (25 lM vs. 34 lM) concentrations and higher Cl (330 lM vs. 230 lM) and DOC (4.4 mM vs. 3.2 mM) concentrations than the Rhizon lysimeters. Also the other lysimeters showed significant differences compared to the centrifuged samples for about half the number of analytes. Centrifuged samples had higher concentrations of all analytes except NO3 and PO4 compared to zero-tension lysimeters and also for all analytes except NO3 and Al compared to Prenart lysimeters. Among the environmental factors considered depth showed an influence to some extent, while sampling occasion had a great significant impact on the difference between the centrifugation method and the Rhizon lysimeters. Factors like individual pits or soil treatment did not show any influence on the difference between the methods.

  • 10.
    Geibe, Christine E
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Holmström, Sara J. M
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Technology and Media.
    van Hees, Patrick A. W
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Impact of lime and ash applications on soil solution chemistry of acidified podzolic soils.2003In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 3, no 4, p. 77-96Article in journal (Refereed)
    Abstract [en]

    Soil solution samples were taken from two sites (Horröd and Hasslöv) in the south part of Sweden to evaluate how soil solution chemistry responded to different treatmentswith dolomite and wood ash. At Horröd, samples were taken four years after application of wood ash, 4.28 ton ha-1 and dolomite, 3.25 ton ha-1. At Hasslöv dolomite, 3.45 ton ha-1 and 8.75 ton ha-1 was applied and samples were taken 15 yr later. It was found that treatment with dolomite at one site (Hasslöv) resulted in higher pH values (<2 pH units) and higher nitrification. It was also found at this site that the total Al and the inorganic Al concentrations decreased with dolomite treatment. The Ca, Mg, DOC, Fe, SO4 2- and Cl- concentrations, mainly in the topsoil, were found to be higher at both sites, following dolomite treatment; Ca and Mg concentrations were 2–8 times higher (<820 mgrM) than in controls (<70 mgrM). Wood ash was found to have less impact. The PO4 concentration in the O2 horizon at Hasslöv decreased due to dolomite-treatment. ANOVA (Analyse of Variance) and PLS (Partial Least Square) were used to evaluate the data from the two sites.

  • 11. Giesler, R.
    et al.
    Ilvesniemi, H.
    Nyberg, L.
    van Hees, P. A. W.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Starr, M.
    Bishop, K.
    Kareinen, T.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Distribution and mobilization of Al, Fe and Si in three podzolic soil profiles in relation to the humus layer.2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 2-4, p. 249-263Article in journal (Refereed)
    Abstract [en]

    The mobilization of Al, Fe and Si in podzols is often associated with the weathering of silicate minerals in the E horizon, downward migration, and their accumulation lower in the soil profile. This study investigated Al, Fe, and Si concentrations in soil water (centrifugation samples) and estimated leaching losses from the humus layer in comparison with those in the mineral E and B horizon. Concentrations of total soluble Al and Fe in soil water were higher in the O and E horizons than in B horizon samples, but not significantly different between the two uppermost horizons. Si concentrations were higher in the E than in the O horizon. The amount of Al and Fe leaching from the E horizon (i.e. input to the B horizon) compared to amount leaching from the O horizon (i.e. the input to the E horizon) ranged from 92% to 163%. Calculated leaching losses from the lower B horizon were less than 3% of the input to the B horizon. The results suggest that a large part of the illuviated Al and Fe in the Bs horizon is derived from the O horizon. Similar values for the Si ranged from 56% to 61% (comparing E horizon output with E horizon input). Budget estimates available for one of the investigated podzols indicated that biocycling via above-ground litter explained < 12% of the estimated annual input of Al and Fe to the forest floor. Inputs of Al and Fe due to upward flow of capillary water accounted for about 26% of the Al and Fe in the O layer. The results show that there is a considerable pool of Si Al, Fe in the humus layer. This pool plays an important part in the present day biogeochemical cycling of these elements in podzolic soils. Several mechanisms possibly involved in the transfer of Al, Fe and Si from the mineral soil to the humus layer are discussed.

  • 12. Gustafsson, Jon Petter
    et al.
    van Hees, Patrick
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Starr, Michael
    Karltun, Erik
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Partitioning of base cations and sulphate between solid and dissolved phases in three podzolized forest soils2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 2-4, p. 311-333Article in journal (Refereed)
    Abstract [en]

    The cation and SO4 adsorption properties of O and B horizons of three podzolised soils in Sweden and Finland were studied through analysing the soil solution at six different sampling occasions and through a set of batch experiments. High concentrations of dissolved organic carbon and cations were found in centrifuged soil solutions from the O horizon, especially during autumn. An analysis using the WHAM-S model suggested that most of the dissolved Ca, Mg, K and Mn were counter-ions, residing in the diffuse layers of dissolved fulvic acids. Hence, the solubility of these cations depended on the solubility of organic matter. Model exercises suggested that the solubility of humics in turn was influenced by seasonal differences in hydrophobicity and by the water content. Furthermore, the model results showed that only a low proportion of the B horizon organic matter was involved in calcium binding. This is probably due to the interaction between organic matter and oxide surfaces in this horizon. In the case of sulphate adsorption in the B horizons, a surface complexation model was tested for its ability to describe batch experiment data and temporal differences in soil water chemistry. This model was based on the diffuse-layer model and it was optimised by adjusting the surface site concentration and the point of zero charge. However, the interaction between Ca2+ and SO4/2- could not be modelled. Comparisons between the model and the field observations proved to be difficult due to a considerable soil heterogeneity. (C) 2000 Elsevier Science B.V.

  • 13. Haslinger, E.
    et al.
    Ottner, F.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Pedogenesis in the Alno carbonatite complex, Sweden2007In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 142, no 1-2, p. 127-135Article in journal (Refereed)
  • 14. Hoffland, Ellis
    et al.
    Kuyper, Thomas W
    Wallander, Håkan
    Plassard, Claude
    Gorbushina, Anna A
    Haselwandter, Kurt
    Holmström, Sara
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Landeweert, Renske
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Rosling, Anna
    Sen, Romin
    Smits, Mark M
    van Hees, Patrick A W.
    Man-Technology-Environment Research Centre, Dept of Natural Sciences, Örebro University, Örebro, Sweden .
    Nico van Breemen, Nico
    The role of fungi in weathering2004In: Frontiers in Ecology and Environment, ISSN 1540-9295, Vol. 2, no 5, p. 258-264Article in journal (Refereed)
    Abstract [en]

    No rock at the Earth’s surface escapes weathering. This process is the primary source of all the essential elements for organisms, except nitrogen and carbon. Since the onset of terrestrial life, weathering has been accelerated under the influence of biota. The study of biological weathering started at the end of the 19th century. Although the role of bacteria (Eubacteria, Archaea) has attracted a lot of interest, until recently the role of fungi has largely been neglected. More recently, however, fungal weathering has become an increasingly important focus of biogeochemical research.

  • 15.
    Holmström, Sara J M
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    van Hees, Patrick A. W.
    Finlay, Roger D
    Siderophores in soil solution and their production by an ectomycorrhizal fungus.2001In: Proceedings. 8th Nordic IHSS Symposium on humic substances - characterisation, dynamics, transport and effects. 28-30 May 2001, Fredriksberg, Denmark, International Humic Substances Society, Nordic Chapter , 2001Conference paper (Other academic)
  • 16.
    Holmström, Sara J M
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Van Hees, Patrik A. W.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Finlay, Roger D
    Siderophores in soil solution and production by an ectomycorrhizal fungus.2002In: Proceedings. First European Workshop on Mineral Weathering by Fungi. Wageningen, The Netherlands, 17-19 October 2002, 2002Conference paper (Other academic)
  • 17.
    Holmström, Sara J M
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Rosling, A
    Finlay, R D
    van Hees, P A W
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Contribution of ectomycorrhizal fungi to biogeochemical processes during iron and calcium limitation: Meeting abstract2009In: GEOCHIMICA ET COSMOCHIMICA ACTA, Pergamon Press, 2009, p. A546-A546Conference paper (Refereed)
  • 18.
    Holmström, Sara
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Finlay, Roger
    van Hees, Patrick
    Siderophores in forest soil solution2004In: Biogeochemistry, ISSN 0168-2563, E-ISSN 1573-515X, Vol. 71, no 2, p. 247-258Article in journal (Refereed)
    Abstract [en]

    Siderophores in soil solution of coniferous forest soils have been chemically identified for the first time. We have identified the siderophores ferrichrome and ferricrocin in soil solution of the upper organic layer by High Performance Liquid Chromatography Mass Spectrometry (HPLC-MS). The soil solutions were sampled from mor layers of podzolic soils from the south and the north of Sweden and from a mor layer overlying granitic rock and intensively colonised by ectomycorrhizal hyphae. Ferrichrome was found in nanomolar concentrations in all soil solutions investigated and ferricrocin only in the soil solution from the mor layer covering a rock and in the soil solution from the north of Sweden. The findings are discussed in relation to the possible role of fungal hyphae and siderophores in weathering minerals in podzolic soils under coniferous forests. Citric and oxalic acid are able to dissolve minerals via complexation of cations from the mineral. Siderophores should be, kinetically and thermodynamically even more efficient complexing agents for trivalent cations than oxalic and citric acid. The present study provides direct for presence of siderophores in soil solution.

  • 19.
    Holmström, Sara
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norrman, S.A.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    van Hees, P.A.W.
    Essén, Sofia
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Siderophores in Soil Solution: 9th Nordic IHSS Symposium on Humic Substances - Abundance and functions of natural organic matter species in soil and water; Sundsvall 2003-05-19-2003-05-212003Conference paper (Other scientific)
    Abstract [en]

    Siderophores in soil solution of coniferous forest soils have been chemically identified. The siderophores ferrichrome and ferricrocin were identified in soil solution of the upper organic layer and also in the liquid medium of a cultivated ectomycorrhizal fungus by High Performance Luquid Chromatography Mass Spectrometry (HPLC-MS).

  • 20.
    Holmström, Sara
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Riise, Gunnhild
    Tau Strand, Line
    Geibe, Christine
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Van Hees, Patrick
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Wu, Qinglan
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Effects of lime and ash treatments on DOC fractions and low molecular weight organic acids in soil solutions of acidified podzolic soils2003In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 3, no 4, p. 97-120Article in journal (Refereed)
    Abstract [en]

    Dissolved organic carbon (DOC) fractions and different low molecular weight organic acids (LMWOAs) were determined in soil solutions from two lime or ash treated Norway spruce sites in the south of Sweden. At Hasslöv, 3.45 t ha-1 or 8.75 t ha-1 dolomite were applied 15 years before sampling. Horröd was treated with 4.28 t ha-1 ash and 3.25 t ha-1 dolomite and sampled four years later. Propionate (7–268 M) and malonate (2–34 M) were the LMWOAsfound in the highest concentrations at Hasslöv. Two other LMWOAs dominated at Horröd, namely citrate (18–64 M)and fumarate (5–31 M). The differences in concentration of most of the determined LMWOAs at Hasslöv were significantly increased due to treatment. The LMWOAs comprised between 1.1–6.3% of the DOC at Hasslöv and 4.5–17.6% at Horröd. At Hasslöv normally 3–10% of the total acidity (TA) was due to LMWOAs and the average specific buffer capacity was 74 ± 22 mmol mol-1C.The total DOC concentration in the mor layer solution was 16 mM for the dolomite treated plots compared to 10 mM at the untreated plot. A major part of the increase in DOC at the treated plots apparently had a hydrophobic character and was of high molecular weight corresponding to 3–10 kDa. The concentration of DOC < 1 kDa in the control and treated plots was similar.

  • 21.
    Holmström, Sara
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    van Hees, Patrick
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Modelling of aluminium chemistry in soil solution of acidified and lime treated podzolic soil2004In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 127, no 3-4, p. 280-292Article in journal (Refereed)
    Abstract [en]

    Soil solutions were taken from untreated and lime treated Norway spruce sites in the south of Sweden. At the limed sites 3.45 t ha−1 (L) or 8.75 t ha−1 (H) dolomite were applied 15 years before sampling. The mean concentration of inorganic Al (AlQR) in the untreated control plots (C) was 37 μM and the concentration of AlQR decreased when the dosages of dolomite treatments increased. For the H plots, with high doses of dolomite treatment the mean concentration of AlQR was 17 μM. The total Al (Altot) also decreased by dolomite treatment, from 72 μM to 56 μM. Propionate (7–268 μM) and malonate (2–34 μM) were the low molecular weight organic acids (LMWOAs) found in the highest concentrations at Hasslöv. The differences in concentration of most of the determined LMWOAs were significantly increased due to treatment. The citrate average concentration for the different plots varied between 2.8 μM and 5.1 μM and the concentration of oxalate had concentrations between 1.7 μM and 2.6 μM. The experimental concentration of Al bound to LMWOAs obtained by ultrafiltration (<1000 Da) of the soil solution was in the mor layer on average 12% for the C plot and the L plots and 4% in the H plots. In the AE horizon the figures were 15% for the C plot and about 7% for the treated L and H plots, and in the Bhs horizon 9% for both the C, L and H plots. Two chemical equilibrium models were evaluated: Winderemere Humic Aqueous Model (WHAM) and a model treating the high molecular weight organic acids as monoprotic. The concentrations of inorganic Al, Al bound to identified LMWOAs and high molecular weights acids in soil solution (mor, AE and Bhs) from untreated and lime treated soil were calculated. The modelled inorganic Al values of the control plot were similar to the concentrations found in the soil solution (AlQR). For the dolomite treated plots the concentration of AlQR (0–40 μM) was higher in soil solution than that modelled by WHAM and the monoprotic model. The experimental concentration of Al bound to LMWOAs obtained by ultrafiltration (<1000 Da) of the soil solution was comparable but always higher than the modelled values. The modelling confirms that an appreciable part of the Al is strongly complexed with LMWOAs in the organic and eluvial horizons of the podzolized soil, suggesting that LMWOAs are efficient weathering agents and important for the formation of the eluvial horizon in podzols. Saturation indices (SI) for two solid Al phases were also calculated, including crystalline gibbsite and proto-imogolite (PI). The SIs for both the C and the treated plots (L and H) showed very broad ranges for the different horizons investigated, indicating undersaturation as well as oversaturation with respect to gibbsite and proto-imogolite.

  • 22. Hongve, D.
    et al.
    Van Hees, P.A.W.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Dissolved components in precipitation water percolated through forest litter2000In: European Journal of Soil Science, ISSN 1351-0754, E-ISSN 1365-2389, Vol. 51, no 4, p. 667-677Article in journal (Refereed)
    Abstract [en]

    Leaves lying on the forest floor are a major source of dissolved organic substances in soil and surface waters, and these substances have important effects in those environments. We used zero-tension lysimeters to study the chemical characteristics of water percolating through litter from various species of forest trees. The leaching rates were greatest in the autumn and declined rapidly thereafter, especially for deciduous litter. During an annual cycle, 2.5-17% of the initial contents of the carbon in the litter was recovered as dissolved organic carbon in percolates. Humus-like substances, hydrophilic acids and hydrophilic neutral compounds constituted the major fractions of dissolved C. Leachates from deciduous leaf litter were only partly biodegradable, and those from spruce needles were scarcely biodegradable. Low molecular weight organic acids constituted 0-12% of the dissolved organic carbon in the percolates of the first autumn sampling and decreased over time. Acetic and formic acids were present at the largest concentrations, up to 30 μmol 1-1 per g litter, and gluconic, pyruvic, fumaric, oxalic and citric acids were also frequent in significant concentrations. Among the aromatic acids, ρ-hydroxybenzoic acid was identified in four out of five autumn samples. The organic components in litter leachates are important for the microbial activity in soil and surface waters. The organic acids enhance weathering and translocation of metals by their ability to form complexes. Litter is also a source of inorganic ions in soil solutions. The dominant cations in the percolates were K+, Ca2+ and Mg2+, and spruce litter also yielded large quantities of Al and Fe.

  • 23.
    Lundström, Ulla
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bain, DC
    Taylor, AF
    Van Hees, PA
    Geibe, Christine E
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Holmström, Sara J
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Melkerud, PA
    Finlay, R
    Jones, DL
    Nyberg, L
    Gustafsson, JP
    Riise, G
    Tau Strand, L
    Effects of acidification and its mitigation with lime and wood ash on forest soil processes in southern Sweden: A Joint Multidisciplinary Study2003In: Water , Air and Soil Pollution: Focus, ISSN 1567-7230, Vol. 3, no 4, p. 167-188Article in journal (Refereed)
  • 24.
    Lundström, Ulla
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bain, D.C.
    Taylor, A.F.S.
    Van Hees, P.A.W.
    Effects of acidifiaction and its mitigation with lime and wood ash on forest soil processes: a review2003In: Water, Air, & Soil Pollution: Focus, ISSN 1567-7230, Vol. 3, no 4, p. 5-28Article in journal (Refereed)
  • 25.
    Lundström, Ulla S
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norström, Sara H
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Vestin, Jenny L K
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Essén, Sofia A
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Dissolved Organic Matter Dynamics of Soil and Stream Water in a Catchment Area, Keynote speaker2006Conference paper (Other scientific)
  • 26.
    Lundström, Ulla
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    van Breemen, N.
    Bain, D. C.
    The podzolization process. A reveiw.2000In: Geoderma, ISSN 0016-7061, Vol. 94, no 2-4, p. 91-107Article, review/survey (Refereed)
    Abstract [en]

    This paper reviews the major mechanisms proposed to explain podzolization. These include the production of organic acids that form soluble complexes with aluminium/iron thereby enhancing weathering, followed by illuviation by precipitation/adsorption processes occurring at greater depth. Precipitation of aluminium and iron is explained by decreasing solubility of increasingly metal-rich complexes, or by microbial degradation of the organic ligand. We also discuss proposed role of inorganic hydroxy-aluminium-silicate sols in podzolization. The paper is introductory to a multidisciplinary study of podzolization performed in the Nordic Countries presented in this volume.

  • 27.
    Lundström, Ulla
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    van Breemen, N.
    Bain, D. C.
    van Hees, P. A. W.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Gielser, R.
    Gustafsson, J. P.
    Ilvesniemi, H.
    Karltun, E
    Melkerud, P. A.
    Olsson, M.
    Riise, G.
    Wahlberg, O.
    Bergelin, A.
    Bishop, K.
    Finlay, R.
    Advances in understanding the podzolization process resulting from a multidisciplinary study of three coniferous forest soils in the Nordic Countries2000In: Geoderma, ISSN 0016-7061, Vol. 94, no 2-4, p. 335-353Article in journal (Refereed)
  • 28.
    Mellander, Per-Erik
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Nambu, Kei
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Elevated CO2 emission during summer nights controlled by soil and air gas densitiesManuscript (Other academic)
  • 29. Moberg, M
    et al.
    Nilsson, E
    Holmström, Sara J. M.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Pettersson, J
    Markidies, K
    Fingerprinting siderophores by the exchange of iron by gallium and subsequent column- switched LC-ICP-MS.2003In: 16th IMSC (The International Mass Spectrometry Society);Edinburgh, Scotland, 2003-08-31 - 2003-09-05, 2003Conference paper (Other academic)
  • 30. Moberg, M.
    et al.
    Nilsson, E. M.
    Holmström, Sara
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Pettersson, J.
    Markides, K.
    Fingerprinting metal-containing biomolecules after reductive displacement of iron by gallium and subsequent column-switched LC-ICP-MS analysis applied on siderophore.2004In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 76, no 9, p. 2618-2622Article in journal (Refereed)
    Abstract [en]

    Column-switching liquid chromatography followed by lowresolution ICPMS was evaluated as a tool for speciation analysis of metal-containing biomolecules. The strategy was applied on siderophores, strong iron chelators of low molecular weight (M-w < 1500). Prior to the LC-ICPMS analysis, reductive displacement of iron by gallium was performed using ascorbate as the reducing agent to increase the sensitivity. Different experimental conditions during the exchange reaction were tested using ferrichrysin and ferrichrome for evaluation. A reaction time of 30 min and a pH of 3.9 gave an exchange yield of 27 and 83% for ferrichrysin and ferrichrome, respectively. A gradient elution profile was also developed to separate gallium-chelated siderophores on a PGC column. Detection limits for standard solutions of ferrichrysin and ferrichrome in the low-nanomolar range were obtained by monitoring the gallium-69 isotope. The combined use of LC-ICPMS and LC-ESI-MS/MS was also evaluated as a tool to identify unknown metal complexes, here siderophores, in field soil solution samples.

  • 31. Moberg, My
    et al.
    Holmström, Sara
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Markides, Karin
    Novel approach to the determination of structurally similar hydroxamate siderophores by column-switching capillary liquid chromatography coupled to mass spectrometry2003In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1020, no 1, p. 91-97Article in journal (Refereed)
    Abstract [en]

    In this study a new approach to determine three different siderophores (ferrichrome, ferrichrysin, ferricrocin) in natural soil solutions as well as in cultures of fungi is presented. The method includes enrichment of the analytes on a short pre-column, packed with C18 material, and subsequent highly selective separation of the analytes on a capillary porous graphitic carbon (PGC) column. In contrast to normal C18 packing materials, porous graphitic carbon offers chromatographic resolution between the three very similar analytes. The selectivity of the method is enhanced even further by the electrospray ionization (ESI) mass spectrometric detection. The combination of a short pre-column and a packed capillary separation column results in a method with high sensitivity. Reported detection limits, defined as the concentration giving the signal-to-noise ratio 3:1, is 27.7 pM for ferrichrome, 46.1 pM for ferricrocin and 37.4 pM for ferrichrysin.

  • 32.
    Nambu, Kei
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    van Hees, P. A. W.
    Essén, Sofia
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Assessing centrifugation technique for obtaining soil solution with respect to leaching of low molecular mass organic acids from pine roots.2005In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 127, no 3-4, p. 263-269Article in journal (Refereed)
    Abstract [en]

    Centrifugation is a common technique to obtain soil solution. However, this method may disrupt living cells in the soil and release their contents into the soil solution. To examine this possibility, we compared leaching of low molecular mass organic acids (LMMOAs) and dissolved organic carbon (DOC) from the root of Scots pine (Pinus sylvestris) packed in quartz sand via extraction by centrifugation and milder procedures of water immersion and suction. Centrifugation enhanced leaching of shikimate appreciably; leaching of DOC, lactate, malate, and phosphate was also significantly enhanced. The concentration leached from the root was greater than 10 mu M for shikimate, and generally ranged between 0.5 and 5 mu M for the other acids. As for actual soil samples, this level of leaching could be appreciably large in upper mineral horizon(s) if the root density is as large as in our experiments and if the concentrations of LMMOAs in the soil matrix are relatively small.

  • 33.
    Nambu, Kei
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    van Hees, P A W
    Jones, D L
    Vinogradoff, S
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Composition of organic solutes and respiration in soils derived from alkaline and non-alkaline parent materials2008In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 144, no 3-4, p. 468-477Article in journal (Refereed)
    Abstract [en]

    Parent material greatly influences pedogenesis and soil nutrient availability and consequently we hypothesized that it would significantly affect the amount of organic solutes in soil, many of which have been implicated in rhizosphere processes linked to plant nutrient uptake. Consequently, we investigated the influence of two contrasting parent materials in which calcite was present or absent (alkaline and non-alkaline soils) on the concentrations of dissolved organic carbon (DOC), low-molecular weight organic acids (LMWOA) and glucose in soil solution. Both soils were under Norway spruce. The dynamics of LMWOAs in soil were also investigated using 14C-labelled citrate and oxalate. Some of the mineral horizons of the alkaline soils showed significantly higher concentrations of DOC, phenolics, and fumarate in soil solution and also a higher basal respiration. No major differences were seen in organic solute status in the organic horizons of the two soil types. LMWOAs were present at low concentrations in soil solution (< 1 to 25 µM). Their mineralization rate significantly decreased with soil depth, however, overall neither their concentration or half-life in soil was markedly affected by parent material. The alkaline soils had significantly higher CO2-to-soil organic C (SOC) ratios, and consequently SOC in the alkaline soils did not seem more chemically stable against mineralization. Considering possible DOC and CO2 efflux rates it was suggested that the equal or larger SOC stocks in alkaline mineral soils were most likely linked to a higher net primary productivity. In conclusion, our study found that parent material exerted only a small effect on the concentration and dynamics of organic solutes in soil solution. This suggests that in comparison to other factors (e.g. vegetation cover, climate etc) parent material may not be a major regulator of the organic solute pool in soil.

  • 34.
    Norström, Sara
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Vestin, Jenny
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Aronsson, Andreas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Influence of dissolved organic carbon (DOC) on the water chemistry in two forested catchments2007In: Proceedings. International Humic Substances Society.11 th Nordic-Baltic Symposium, Functioning of NOM in Environment, Joensuu, Finland June 10-13, 2007, 2007Conference paper (Refereed)
  • 35.
    Norström, Sara
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Vestin, Jenny L K
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Initial effects of wood ash application on the stream water chemistry in a boreal catchment in central Sweden2011In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 221, no 1-4, p. 123-136Article in journal (Refereed)
    Abstract [en]

    Due to increased whole-tree harvesting in Swedish forestry, concern has been raised that a depletion of nutrients in forest soil will arise. The Swedish Forest Agency recommends compensation fertilization with wood ash to ensure that unwanted effects are avoided in the nutrient balance of the forest soil and in the quality of surface water. In this investigation, the chemistry of two first-order streams, of which one was subjected to a catchment scale treatment with 3 tonnes of self-hardened wood ash/ha in the fall of 2004, was monitored during 2003-2006. Large seasonal variations in stream water chemistry made changes due to ash application difficult to detect, but evaluating the ash treatment effects through comparison of the stream water of the treated catchment with the reference was possible via statistical tools such as randomized intervention analysis in combination with cumulative sum charts. The wood ash application did not yield any significant effect on the pH in the stream water and hence did not affect the bicarbonate system. However, dissolved organic carbon increased, a previously unreported effect of WAA, bringing about an increase of organic anions in the stream water. The wood ash application also induced significant increases for Ca, Mg, K, Si, Cl and malonate, of which K was most prominent. Although significant, the changes induced by the wood ash application were all small compared to the seasonal variations. As a tool to counteract acidification of surface waters, WAA seems to have limited initial effects

  • 36.
    Norström, Sara H
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Vestin, Jenny L. K.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Initial effects of wood ash application to soil and soil solution chemistry in a small, boreal watershed2012In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 187, p. 85-93Article in journal (Refereed)
    Abstract [en]

    With the conception that whole tree harvesting leads to an impoverishment of forest soils wood ash application is recommended, with the foremost benefits being increased pH in soil and subsequent surface waters, and recycling of nutrients from the wood ash.

    In this investigation a small boreal catchment in central Sweden was studied for two years before and two years after treatment with the maximum recommended dose, 3 tonnes/ha, of crushed, self-hardened wood ash. The sampling area was situated in a slope towards a stream, to include the effect on both recharge- and discharge areas with different soil constitutions. The soil solution chemistry, exchangeable pool of cations and potential heavy metal accumulation in berries were studied. Temporary increases in soil solution concentration were found for K in the recharge area and Ca and SO4 in the discharge area when comparing ashed and control areas. No change in exchangeable cations was observed during the study period, and no increase of heavy metals in bilberries did occur. These small changes in the constitution of the soil solution do not suggest wood ash application as a method to improve soil quality in an initial phase.

  • 37.
    Norström, Sara H
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Vestin, Jenny LK
    Swedish geotechnical institute.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Influences of dissolved organic carbon on stream water chemistry in two forested catchments in central Sweden2010In: Biogeochemistry, ISSN 0168-2563, E-ISSN 1573-515X, Vol. 101, no 1-3, p. 229-241Article in journal (Refereed)
    Abstract [en]

    Stream water chemistry in two headwater streams draining two small, adjacent catchments in Bispgården, central Sweden was studied during the 2003 and 2004 growing seasons. The two catchments closely resemble each other in regard to size, shape and drainage density, with the major difference found in the area of wetland lining the streambeds. The emphasis of the study was to investigate the stream water chemistry of these closely resembling catchments, regarding the quality and quantity of dissolved organic carbon (DOC) and its influence on the concentrations of di- and trivalent cations. The streams showed significant differences in the content and size distribution of DOC and in the distribution of cations between the different size fractions. For both streams the high flow events induced by precipitation influenced the chemistry of the streams through increase of organic matter and its associated cations. Fanbergsbäcken, with relatively low pH and high DOC concentration, had a greater amount of high molecular mass (HMM) DOC to which approximately 75% of Al and Fe and about 50% of Ca and Mg were associated. Gråbergsbäcken, with a higher pH and lower DOC level, had approximately 65% of Al, 40% of Fe and 30% of Ca and Mg associated to its HMM DOC fraction. Sixteen different low molecular mass organic acids were found in the stream water, of which oxalic and lactic acid were present in the highest concentrations.

  • 38. Nyberg, Lars
    et al.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Söderberg, Ulf
    Danielsson, Rolf
    van Hees, Patrick
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Does soil acidification affect spruce needle chemical composition and tree growth?2001In: Water, Air and Soil Pollution, Focus, ISSN 1567-7230, Vol. 1, no 1/2, p. 242-263Article in journal (Refereed)
    Abstract [en]

    In 1994, a large survey of soil chemistry was undertaken in the county of Värmland in central Sweden (Lundström et al., 1998). The southern part of the county was affected by soil acidification whereas there were no such indications in the northern part. To investigate the influence of soil chemistry on the trees at the specific sites, the survey was continued by an analysis of needle chemistry (Norway spruce) which was undertaken at 150 of the 180 sites, and of tree growth at 65 of the 180 sites. Growth was expressed as a ratio between expected growth, estimated with a national, empirical growth model, and the growth observed in the field. In statistical analyses, using rank correlation, PCA and PLS, there were only weak indications of an influence of soil chemistry on needle chemistry and on tree growth. A moderate correlation between nitrogen and sulphur in needles was found, which was interpreted as an effect of deposition and of processes in the tree canopy. No obvious regional pattern of the growth ratio was found, in contrast to the clear pattern of soil acidification. The statistical analysis could not with any certainty point out any of the soil chemistry variables as especially important for the tree growth ratio.

  • 39. Riise, G.
    et al.
    van Hees, P. A. W.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Tau Strand, L.
    Mobility of different size fractions of organic carbon, Al, Fe, Mn and Si in podzols2000In: Geoderma, ISSN 0016-7061, Vol. 94, no 2-4, p. 237-247Article in journal (Refereed)
    Abstract [en]

    The influence of size distribution on the translocation of organic carbon, Fe, Al, Mn and Si in soil waters, has been studied in Scandinavian podzol profiles from three different locations. Soil solutions from different horizons have been filtered through a 0.45 μm membrane filter prior to further size fractionation by ultramembrane techniques. Organic carbon, Fe, Al, Mn and Si were determined in: (I) a colloidal fraction-nominal molecular weight cutoff > 3 kDa, (II) a medium size fraction-nominal molecular weight cutoff 1-3 kDa, and (III) a low molecular size fraction-nominal molecular weight cutoff < 1 kDa. The colloidal fraction comprise large proportions of organic carbon in the O and the E horizons, while low molecular size organic carbon fractions increase with depth in the B horizon on a percentage basis. A major part of Fe and Al seems to be associated with the colloidal fraction of organic carbon in the O horizon, and results suggest that colloidal organic matter contribute to the vertical translocation of metals through the E horizon. Maximum concentrations of Si, Al and Fe are found in the E horizon. Concentration of colloidal Si is significantly higher in the E than the other horizons. Although the total concentration of Si is four times the concentration of Al, colloidal Si and Al are present in more or less similar concentrations. This suggest that Si and Al are associated with each other in colloids in the E horizon. Equilibrium calculations, however, indicate that proto-imogolite sols are not very likely, and correlation coefficients rather suggest interaction of Al with colloidal organic carbon. The major part of Fe is in the colloidal fraction in all horizons. In contrast, Mn decreases sharply with depth, and is generally in a low molecular weight form. This indicates that Mn is related to the litter turnover process and that Mn takes little part in the podzolization process.

  • 40.
    Smits, Mark M
    et al.
    Microbial Ecology, Lund University, Ecology Building, SE-223 62 Lund, Sweden.
    Herrmann, Anke M
    Department of Chemistry, SLU, PO Box 7015, SE-750 07 Uppsala, Sweden.
    Duane, Michael
    Department of Earth and Environmental Sciencea, Faculty of Science, PO Box 5969, Safat 13060, Kuwait.
    Duckworth, Owen W
    Department of Soil Science, North Carolina State University, PO Box 7619, Raleigh, North Carolina, 27695 7619, USA.
    Bonneville, S
    Benning, L G
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    The fungal-mineral interface: Challanges and considerations of micro-analytical developments2009In: Fungal Biology Reviews, ISSN 1749-4613, E-ISSN 1878-0253, Vol. 23, no 4, p. 122-131Article in journal (Refereed)
    Abstract [en]

    Over recent years, the role of fungi, especially mycorrhizal fungi, in the weathering of rock-forming minerals has been increasingly recognised. Much of our understanding of the effects of fungi on mineral weathering is based on macroscopic studies. However, the ability of fungi to translocate materials, including organic acids and siderophores, to specific areas of a mineral surface leads to significant spatial heterogeneity in the weathering process. Thus, geomycologists are confronted with unique challenges of how to comprehend and quantify such a high degree of diversity and complicated arrays of interactions. Recent advances in experimental and analytical techniques have increased our ability to probe the fungal-mineral interface at the resolution necessary to decouple significant biogeochemical processes. Modern microscopy, spectroscopy, mass spectrometry, wet chemistry, and scattering techniques allow for the selective extraction of physical, chemical, and structural data at the micro- to nano-scale. These techniques offer exciting possibilities to study fungal-mineral interactions at the scale of individual hyphae. In this review, we give an overview of some of these techniques with their characteristics, advantages and limitations, and how they can be used to further our understanding of biotic mineral weathering.

  • 41.
    Thurdin, Rickard T.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    van Hees, P. A. W.
    Örebro University, Örebro.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bio fuel ash in a road construction: Impact on soil solution chemistry2006In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 26, no 6, p. 599-613Article in journal (Refereed)
    Abstract [en]

    Limited natural resources and landfill space and increasing amounts of ash produced from incineration of bio fuel and solid wastes have created a demand for useful applications of ash of which road construction is one. Here the environmental impact of a fly ash layer in a reconstructed road was evaluated by studying the soil solution chemistry in the ash layer, at two depths in the soil below and at two depths in the ditch using a centrifugation drainage technique. The road was situated about 20 km west of Sollefteå, (63˚ 16� 33�N, 17˚12�52�E) in the middle of Sweden. Two years after the application of the ash the concentrations of zinc were increasing in the ash layer solutions while concentrations of cadmium were stabilising. Below the ash layer in the road an initial increase of the pH was observed and the concentrations of potassium, sulphate and cadmium showed an increase while copper and mercury showed decreasing concentrations in the road and the ditch soil solutions. The concentrations in the ditch soil solutions were generally much lower compared to the road. Concentrations of calcium in the ash layer solutions indicated that hardening had taken place.

  • 42.
    Thurdin, Rikard
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    A comparison of sampling methods for environmental monitoring of ash road constructionManuscript (preprint) (Other academic)
  • 43. Tranvik, L J
    et al.
    van Hees, P A W
    Lundstrom, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Abundance and functions of natural organic matter species in soil and water2004In: Aquatic Sciences, ISSN 1015-1621, E-ISSN 1420-9055, Vol. 66, no 2, p. 149-150Article in journal (Refereed)
  • 44. van Breemen, Nico
    et al.
    Finlay, Roger
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Jongmans, Antoine
    Giesler, Reiner
    Olsson, Mats
    Mycorrhizal weathering: A true case of mineral nutrition?2000In: Biogeochemistry, ISSN 0168-2563, E-ISSN 1573-515X, Vol. 49, no 1, p. 53-67Article in journal (Refereed)
    Abstract [en]

    Weatherable minerals in all podzol surface soils and shallow granitic rock under European coniferous forests studied hitherto are criss-crossed by numerous open, tubular pores, 3-10 μm in width. We hypothesize that these pores were formed by complex-forming, low-molecular weight organic acids exuded by or formed in association with mycorrhizal fungi. It is well known that ectomycorrhizal mycelium represents a greatly extended, and better distributed, surface area for the absorption of nutrients. However, there have been few investigations of how the whereabouts of individual hypha affect nutrient uptake. The results presented here provide direct evidence that the mycelium is able to penetrate, and most probably create, microsites which are inaccessible to plant roots and isolated from bulk soil solution phenomena. Dissolved products could be translocated to the host plant roots, bypassing the soil solution with often toxic concentration of Al3+ from acid rain, and bypassing competition for nutrient uptake by other organisms. Furthermore, there is strong evidence that 'rock-eating' mycorrhizal fungi play a role in the formation of podzol E horizons. The partly speculative interpretations presented here challenge conventional ideas about (1) the importance of nutrient uptake from the bulk soil solution (2) criteria for critical loads of acid atmospheric deposition for forests, and (3) the process of podzolization.

  • 45. van Breemen, Nico
    et al.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Jongmans, Antoine
    Do plants drive podzolization via rock-eating mycorrizhal fungi?2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 2-4, p. 163-171Article in journal (Refereed)
    Abstract [en]

    Weathering and supply of nutrients derived from minerals to plants is known to be stimulated by plant symbiotic mycorrhizal fungi. Nutrients are generally thought to pass the bulk soil solution before plant uptake. Jongmans et al. [Jongmans, A.G., van Breemen, N., Lundstrom, U.S., van Hees, P.A.W., Finlay, R.D., Srinivasan M., Unestam, T., Giesler, R., Melkerud, P.-A., Olsson, M., 1997. Rock-eating fungi. Nature, 389, 682-683] showed that (ectomycorrhizal) fungi drill innumerable narrow cylindrical pores (diameter 3-10 μm) into weatherable minerals in podzol E horizons. The fungi probably form micropores by exuding strongly complexing low-molecular weight organic acids at their hyphal tips, causing highly local dissolution of Al silicates. Micropores occurred in all thin sections of podzols under Pinus sylvestris and Picea abies available from Sweden (3), Finland (2), Switzerland (2), Denmark (2) and the Netherlands (3), but not in the few available thin sections of non-podzolic soils under broadleaves. Many weatherable minerals in the podzol E horizon appeared to be perforated, as opposed to few if any in the abruptly underlying B horizon, suggesting a link to podzolization. High concentrations of Al and Si in organic surface horizons under boreal and temperate conifers can be explained by transfer by hypha of weathering products from the minerals to mycorrhizal roots in the O horizon, followed by release of weathering products that are not taken up by the plants. Rock-eating ectomycorrhizal fungi suggest a more direct role for plants in podzolization than hitherto realized, providing tight coupling between podzolization and mineral weathering. Preliminary observations, however, indicate that mycorrhizal fungi do not play a role in podzolization under Kauri (Agathis australis) in New Zealand. (C) 2000 Elsevier Science B.V.

  • 46.
    van Hees, P. A. W.
    et al.
    Man-Technology-Research Centre, Department of Natural Sciences, Örebro University, S-701 82 Örebro, Sweden.
    Jones, D. L.
    Nyberg, L.
    Holmström, Sara
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Godbold, D. L.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Modelling low molecular weight organic acid dynamics in forest soils2004In: Soil Biology and Biochemistry, ISSN 0038-0717, E-ISSN 1879-3428, Vol. 37, no 3, p. 517-531Article in journal (Refereed)
    Abstract [en]

    Low molecular weight organic acids such as citrate and oxalate have been hypothesized to play a key role in rhizosphere ecology and pedogenesis. A mathematical site-specific model, DYNLOW, was constructed to describe the temporal and spatial dynamics of these organic acids in coniferous forest soils using the modelling software STELLA®. Experimentally derived values for biodegradation, adsorption, and daily values of soil temperature, moisture and hydrological flow were used to parameterize the model. The model describes the dynamics and downward movement of oxalate and citrate through the horizons (O, AE, E, Bhs, Bs) of three podzolic soil profiles in Sweden. After calibration, the model predicted average soil solution organic acid concentrations ranging from <1 to 90 μM, which was in agreement with experimental measurements (<1 to 116 μM). The model results indicated that microbial degradation of organic acids was in quantitative terms the biggest process regulating soil solution concentrations. Primary production rates of organic acid in the soil were predicted to be high (<1 to 1250 nmol g−1 soil d−1) in comparison to the amount present at steady state in the soil solution pool (<0.1 to 240 nmol g−1 soil). The downward transfer of organic acids between soil horizons due to mass flow was predicted to be a small flux (<0.1 to 3% of the total loss) compared to that lost by microbial biodegradation. The model predicted that the amount of basal soil respiration that could be attributable to the microbial turnover of organic acids was on average 19±22% of the basal CO2 production across all sites and horizons for citrate and 7±7% for oxalate. The model results are discussed in the context of pedogenesis, forest soil respiration and organic matter production.

  • 47.
    van Hees, P. A. W.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Equilibrium models of aluminium and iron complexation with different organic acids in soil solution2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 2-4, p. 201-221Article in journal (Refereed)
    Abstract [en]

    The percentage of Al and Fe bound to identified low molecular weight (LMW) organic acids and phosphate in soil solution was calculated using a chemical equilibrium model. The highest fractions were obtained for the O1 horizon solutions with median values between 38-49% for Al and 18-29% for Fe. Generally the percentage declined in the deeper horizons. Acceptable agreement with experimental values using ultrafiltration (< 1000 D) was found especially for the spring and summer samplings. In the autumn samples, larger deviations between the modelled and ultrafiltered fractions were found. The major part of the remaining Al and Fe in solution was calculated to be bound to undefined organic acids most likely of higher molecular weight. Speciation studies of some individual organic acids are presented. Citric acid proved to be the most important complex former of the LMW acids in the O and E horizons while oxalic acid was dominant in the B horizon solutions. The total level of organic complexation of Al, Fe, Ca and Mg was also studied. It was found that > 85% of the Al and > 95% of the Fe were organically bound. The opposite was seen for Ca and Mg for which > 85% was modelled to occur as inorganic ions. The modelling results support the theory that LMW organic acids contribute to the translocation of Al and Fe in the podzolization process.

  • 48.
    van Hees, P. A. W.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Danielsson, R.
    Department of Analytical Chemistry, Uppsala University, P.O. Box 531, S-751 21 Uppsala.
    Nyberg, L.
    Department of Environmental Sciences, University of Karlstad, S-651 88 Karlstad.
    Controlling mechanisms of aluminium in soil solution: An evaluation of 180 of podzolic forest soils2001In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 45, no 6-7, p. 1091-1101Article in journal (Refereed)
    Abstract [en]

    To monitor the level of soil acidification in the county of Värmland in the middle west of Sweden 180 podzolic forest soils were investigated. Soil solutions from four horizons were obtained by centrifugation and the soil was sampled for a determination of the exchangeable pool by extraction. The concentrations of inorganic Al and its fraction of the total Al in solution were greater in the south of the county (up to 50%). The factors influencing the total Al and free inorganic Al3+ in the soil solutions were evaluated. Saturation indices (SI) for five different mineral phases were calculated but none implied equilibrium conditions. The relationships between pAl3+ and pH (in the pH range 4-6.2) gave slopes of about 1, which indicated that ion exchange/complexation reactions may be important for determining the Al3+ concentration in the B and C horizons. In the E horizon solutions complexation with soluble organic acids seemed to be the major factor which influenced the Al3+ activity. The influence of organic matter on Al solubility was supported by partial least square (PLS) regressions.

  • 49.
    van Hees, P. A. W.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Giesler, R.
    Low molecular weight acids and their Al-complexes in soil solution- Composition, distribution and seasonal variation in three podzolized soils.2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 2-4, p. 173-200Article in journal (Refereed)
    Abstract [en]

    Low molecular weight organic acids have been determined qualitatively and quantitatively over a growing season in the soil solution of three podzolized soil profiles. Several low molecular weight (LMW) acids such as citric, shikimic, oxalic, fumaric, formic, acetic, malonic, malic, lactic and t-aconitic acids were identified in the range < 1-1100 μM. Citric acid was the acid generally present at the highest concentrations (15-250 μM) in the upper layers while shikimic and oxalic acids could be observed in all horizons at lower concentrations. The levels of LMW organic acids were always greatest in the organic (O) horizon, and declined in the deeper layers. The fraction of the dissolved organic carbon and total acidity made up by LMW acids was generally in the range 0.5-5% and 0.5-15%, respectively. No apparent seasonal variations were observed, and the differences between the sites were little. The fraction of Al in soil solution bound to LMW organic acids was evaluated using ultrafiltration (< 1000D) and size exclusion chromatography. Fe < 1000D was also determined. For the O1 horizon about 40% and 20% of the Al and Fe, respectively, were detected in the LMW fraction (< 1000D). The LMW fraction of the two elements decreased deeper down in the profile, but relative increases were sometimes observed in the B1 horizon. Labile and LMW (< 1000D) Si were determined by FIA and ultrafiltration, respectively. The results show that a major fraction (80-100%) of the Si is labile and of low molecular weight, most likely silicic acid. (C) 2000 Elsevier Science B.V.

  • 50.
    van Hees, P. A. W.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Starr, M.
    Giesler, R.
    Factors influencing aluminium concentrations in soil solution of podzols2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 2-4, p. 289-310Article in journal (Refereed)
    Abstract [en]

    Mechanisms controlling the concentrations of free Al3+ and total Al in the soil solution from three podzolic soils were evaluated. Saturation indices (SI) were calculated for five mineral phases, but no single phase determined the Al3+ activity. E horizon samples were found to be undersaturated with respect to all phases. A more detailed equilibrium study indicated that formation of proto-imogolite sols was commonly possible in B horizon solutions with pH > 5. The poor relationship between pH and pAl3+ in the E and B1 horizons did not support control by exchange reactions with solid organic matter, although partial least square (PLS) regressions indicated importance of soil-exchangeable Al in the B and C horizons. It was concluded that in the E and most of the B1 horizon solutions, Al3+ activity is controlled by equilibrium with soluble organic acids which was supported by the PLS regressions. (C) 2000 Elsevier Science B.V.

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