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Jansson, Mats
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Publications (10 of 82) Show all publications
Berggren, M., Klaus, M., Selvam, B. P., Ström, L., Laudon, H., Jansson, M. & Karlsson, J. (2018). Quality transformation of dissolved organic carbon during water transit through lakes: contrasting controls by photochemical and biological processes. Biogeosciences, 15(2), 457-470
Open this publication in new window or tab >>Quality transformation of dissolved organic carbon during water transit through lakes: contrasting controls by photochemical and biological processes
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2018 (English)In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 15, no 2, p. 457-470Article in journal (Refereed) Published
Abstract [en]

Dissolved organic carbon (DOC) may be removed, transformed, or added during water transit through lakes, resulting in changes in DOC composition and pigmentation (color). However, the process-based understanding of these changes is incomplete, especially for headwater lakes. We hypothesized that because heterotrophic bacteria preferentially consume noncolored DOC, while photochemical processing removes colored fractions, the overall changes in DOC color upon water passage through a lake depend on the relative importance of these two processes, accordingly. To test this hypothesis we combined laboratory experiments with field studies in nine boreal lakes, assessing both the relative importance of different DOC decay processes (biological or photochemical) and the loss of color during water transit time (WTT) through the lakes. We found that influence from photo-decay dominated changes in DOC quality in the epilimnia of relatively clear headwater lakes, resulting in systematic and selective net losses of colored DOC. However, in highly pigmented brown-water lakes (absorbance at 420 nm > 7 m(-1)) biological processes dominated, and there was no systematic relationship between color loss and WTT. Moreover, in situ data and dark experiments supported our hypothesis on the selective microbial removal of nonpigmented DOC, mainly of low molecular weight, leading to persistent water color in these highly colored lakes. Our study shows that brown headwater lakes may not conform to the commonly reported pattern of the selective removal of colored constituents in freshwaters, as DOC can show a sustained degree of pigmentation upon transit through these lakes.

Place, publisher, year, edition, pages
European Geosciences Union (EGU), 2018
National Category
Ecology Environmental Sciences
Identifiers
urn:nbn:se:umu:diva-144829 (URN)10.5194/bg-15-457-2018 (DOI)000423346300001 ()
Available from: 2018-03-02 Created: 2018-03-02 Last updated: 2018-08-20Bibliographically approved
Soares, A. R. A., Bergström, A.-K., Sponseller, R. A., Moberg, J. M., Giesler, R., Kritzberg, E. S., . . . Berggren, M. (2017). New insights on resource stoichiometry: assessing availability of carbon, nitrogen, and phosphorus to bacterioplankton. Biogeosciences, 14(6), 1527-1539
Open this publication in new window or tab >>New insights on resource stoichiometry: assessing availability of carbon, nitrogen, and phosphorus to bacterioplankton
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2017 (English)In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 14, no 6, p. 1527-1539Article in journal (Refereed) Published
Abstract [en]

Boreal lake and river ecosystems receive large quantities of organic nutrients and carbon (C) from their catchments. How bacterioplankton respond to these inputs is not well understood, in part because we base our understanding and predictions on "total pools", yet we know little about the stoichiometry of bioavailable elements within organic matter. We designed bioassays with the purpose of exhausting the pools of readily bioavailable dissolved organic carbon (BDOC), bioavailable dissolved nitrogen (BDN), and bioavailable dissolved phosphorus (BDP) as fast as possible. Applying the method in four boreal lakes at base-flow conditions yielded concentrations of bioavailable resources in the range 105-693 mu g CL-1 for BDOC (2% of initial total DOC), 24-288 mu g NL-1 for BDN (31% of initial total dissolved nitrogen), and 0.2-17 mu g PL-1 for BDP (49% of initial total dissolved phosphorus). Thus, relative bioavailability increased from carbon (C) to nitrogen (N) to phosphorus (P). We show that the main fraction of bioavailable nutrients is organic, representing 80% of BDN and 61% of BDP. In addition, we demonstrate that total C : N and C: P ratios are as much as 13-fold higher than C : N and C: P ratios for bioavailable resource fractions. Further, by applying additional bioavailability measurements to seven widely distributed rivers, we provide support for a general pattern of relatively high bioavailability of P and N in relation to C. Altogether, our findings underscore the poor availability of C for support of bacterial metabolism in boreal C-rich fresh-waters, and suggest that these ecosystems are very sensitive to increased input of bioavailable DOC.

National Category
Ecology
Identifiers
urn:nbn:se:umu:diva-133745 (URN)10.5194/bg-14-1527-2017 (DOI)000398193100004 ()
Available from: 2017-05-09 Created: 2017-05-09 Last updated: 2018-06-09Bibliographically approved
Jäger, C. G., Vrede, T., Persson, L. & Jansson, M. (2014). Interactions between metazoans, autotrophs, mixotrophs and bacterioplankton in nutrient-depleted high DOC environments: a long-term experiment. Freshwater Biology, 59(8), 1596-1607
Open this publication in new window or tab >>Interactions between metazoans, autotrophs, mixotrophs and bacterioplankton in nutrient-depleted high DOC environments: a long-term experiment
2014 (English)In: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 59, no 8, p. 1596-1607Article in journal (Refereed) Published
Abstract [en]

1. Humic lakes with a high external supply of DOC and low input of nutrients can often support a high biomass of metazoan zooplankton. In such lakes, autotrophic algae compete with bacteria for inorganic nutrients, but bacteria support mixotrophic growth. Consequently, planktonic communities are often dominated by mixotrophic flagellates, while obligate autotrophic phytoplankton occurs in low numbers for extended periods.

2. To test the importance of autotrophic phytoplankton and mixotrophic flagellates as food resources for metazoan grazers and, in turn, the feedback effects of grazers on basal food-web interactions, we conducted a long-term experiment where we simulated abiotic resource relationships of humic lakes (high DOC [glucose] and low P input). We examined the population dynamics of Daphnia galeata when inoculated in systems with autotrophic algae only, mixotrophic algae only and a mixture of autotrophic and mixotrophic algae, and how the systems changed after the inoculation of Daphnia. All combinations were run at high-and low-light conditions to analyse the effects of light on food quantity and quality.

3. Daphnia grew to high densities only when mixotrophs were present at high-light conditions and showed no or only weak growth at low-light conditions or with autotrophs as the only food source.

4. Autotrophic algae and bacteria showed a strong competition for nutrients. Autotrophic algae were released from competition for nutrients after Daphnia grazed on bacteria, which led to a probable change of the bacteria community to less edible but less competitive taxa. As a consequence, there was a mutualistic interaction between autotrophs and mixotrophs before Daphnia were introduced which turned into competition after Daphnia inoculation.

5. We suggest that mixotrophic flagellates can be a critical resource for cladocerans and thereby also have a cascading effect on higher trophic levels, and cladocerans, in turn, have important indirect effects on basal planktonic food webs; hence, both might affect whole lake ecosystems.

Keywords
Daphnia, Dinobryon, food quality, indirect effects, Scenedesmus
National Category
Biological Sciences
Identifiers
urn:nbn:se:umu:diva-92262 (URN)10.1111/fwb.12366 (DOI)000339385100003 ()
Available from: 2014-09-15 Created: 2014-08-25 Last updated: 2018-06-07Bibliographically approved
Karlsson, J., Berggren, M., Ask, J., Byström, P., Jonsson, A., Laudon, H. & Jansson, M. (2014). Response to Comment: Terrestrial support of pelagic consumers in unproductive lakes- Uncertainty and potential in assessments using stable isotopes. Limnology and Oceanography, 59(5), 1800-1803
Open this publication in new window or tab >>Response to Comment: Terrestrial support of pelagic consumers in unproductive lakes- Uncertainty and potential in assessments using stable isotopes
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2014 (English)In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 59, no 5, p. 1800-1803Article in journal, Editorial material (Refereed) Published
National Category
Environmental Sciences
Identifiers
urn:nbn:se:umu:diva-98410 (URN)10.4319/lo.2014.59.5.1800 (DOI)000345462100027 ()
Available from: 2015-01-22 Created: 2015-01-22 Last updated: 2018-06-07Bibliographically approved
Rodriguez, P., Ask, J., Hein, C. L., Jansson, M. & Karlsson, J. (2013). Benthic organic carbon release stimulates bacterioplankton production in a clear-water subarctic lake. Freshwater Science, 32(1), 176-182
Open this publication in new window or tab >>Benthic organic carbon release stimulates bacterioplankton production in a clear-water subarctic lake
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2013 (English)In: Freshwater Science, ISSN 2161-9565, Vol. 32, no 1, p. 176-182Article in journal (Refereed) Published
Abstract [en]

We carried out a set of experiments in a small clear-water lake in northern Sweden during summer 2010 to assess the effect of organic C (OC) released from epipelic algae on pelagic bacterial production (BP). The release rate of OC (dissolved and particulate) from epipelic algae was similar to 45.4 ng C m(-2) h(-1) Bacterioplankton uptake of dissolved OC was P-limited, and pelagic primary production (PP) was colimited by N and P. Pelagic BP (3.2 +/- 6 mu g C L-1 h(-1)) exceeded pelagic PP (0.012 +/- 0.008 mu g C L-1 h(-1)). Pelagic BP was higher in lake water in contact with sediments and the epipelic algae growing on their surface than in water separated from the sediments. Epipelic algae release OC to lake water and potentially stimulate pelagic BP. However, exploitation of benthic OC probably is suboptimal because of nutrient limitation (primarily by inorganic P) of BP.

Place, publisher, year, edition, pages
Society for Freshwater Science, 2013
Keywords
sediment, benthic algae, organic carbon, bacterioplankton production, clear-water lake
National Category
Environmental Sciences Ecology
Identifiers
urn:nbn:se:umu:diva-67031 (URN)10.1899/12-005.1 (DOI)000314670800015 ()
Available from: 2013-03-15 Created: 2013-03-12 Last updated: 2018-06-08Bibliographically approved
Vestergren, J. E., Vincent, A. G., Persson, P., Jansson, M., Ilstedt, U., Giesler, R., . . . Gröbner, G. (2013). Novel Approaches for Identifying Phosphorus Species in Terrestrial and Aquatic Ecosystems with P-31 NMR. Paper presented at 57th Annual Meeting of the Biophysical-Society, FEB 02-06, 2013, Philadelphia, PA. Biophysical Journal, 104(2), 501A-502A
Open this publication in new window or tab >>Novel Approaches for Identifying Phosphorus Species in Terrestrial and Aquatic Ecosystems with P-31 NMR
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2013 (English)In: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 104, no 2, p. 501A-502AArticle in journal, Meeting abstract (Other academic) Published
National Category
Biophysics
Identifiers
urn:nbn:se:umu:diva-68922 (URN)000316074305050 ()
Conference
57th Annual Meeting of the Biophysical-Society, FEB 02-06, 2013, Philadelphia, PA
Available from: 2013-05-02 Created: 2013-04-29 Last updated: 2018-06-08Bibliographically approved
Jansson, M., Berggren, M., Laudon, H. & Jonsson, A. (2012). Bioavailable phosphorus in humic headwater streams in boreal Sweden. Limnology and Oceanography, 57(4), 1161-1170
Open this publication in new window or tab >>Bioavailable phosphorus in humic headwater streams in boreal Sweden
2012 (English)In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 57, no 4, p. 1161-1170Article in journal (Refereed) Published
Abstract [en]

Bioavailable phosphorus (BAP) concentrations were determined nine times between April and October 2010 in two humic boreal headwater streams draining forest-and mire-dominated catchments. BAP was analyzed in a bioassay in which natural P-limited bacterioplankton grew with natural P as the sole P source. In both streams, approximately 90% of the BAP occurred as dissolved species (passing a 0.2-mu m filter), consisting partly of low-molecular-weight forms (passing a filter with nominal cutoff at 1 kDa) and partly of high-molecular-weight forms (passing a 0.2-mu m filter but not a 1-kDa filter). Concentrations of total dissolved BAP varied between 1 mu g L-1 and 14 mu g L-1, with the highest values in the middle of the summer. Compared to the forest stream, BAP concentrations were generally higher in the mire stream, where it occasionally amounted to nearly 50% of total P. Molybdate reactive phosphorus overestimated BAP considerably. Most of the BAP was in forms other than free orthophosphate. Temporal BAP variations showed no relationships with dissolved organic carbon (C) or iron but were positively related to air temperature and negatively related to the absorbance ratio (a254 : a365) of organic compounds in the water, indicating connections between terrestrial export of BAP and temperature-dependent terrestrial C metabolism. Concentrations of BAP can relieve stream bacteria from P limitation, and a significant share of BAP exported to streams can reach and be used in downstream lakes.

National Category
Ecology
Identifiers
urn:nbn:se:umu:diva-59734 (URN)10.4319/lo.2012.57.4.1161 (DOI)000307269300021 ()
Available from: 2012-10-18 Created: 2012-09-25 Last updated: 2018-06-08Bibliographically approved
Jansson, M., Karlsson, J. & Jonsson, A. (2012). Carbon dioxide supersaturation promotes primary production in lakes [Letter to the editor]. Ecology Letters, 15(6), 527-532
Open this publication in new window or tab >>Carbon dioxide supersaturation promotes primary production in lakes
2012 (English)In: Ecology Letters, ISSN 1461-023X, E-ISSN 1461-0248, Vol. 15, no 6, p. 527-532Article in journal, Letter (Refereed) Published
Abstract [en]

Ecology Letters (2012) Abstract A majority of the worlds lakes are supersaturated with respect to carbon dioxide (CO2). By experimental manipulation of the CO2 concentration in supersaturated boreal lakes, we demonstrate that phytoplankton primary production was up to 10 times higher in supersaturated lake water in comparison with water with CO2 at equilibrium concentrations and that CO2, together with nutrients, explained most of the variation in pelagic primary production and phytoplankton biomass over a wide variety of unproductive lakes. These results suggest that phytoplankton can be co-limited by CO2 and nutrients in unproductive lakes. As import of terrestrial organic carbon and its subsequent microbial mineralisation in lakes is a driving force of CO2-supersaturation our results suggest that lake productivity and carbon cycling may respond to variations in terrestrial organic carbon export, (e.g. caused by land use or climate change) in ways not described before.

Keywords
CO2-supersaturation, lake ecosystems, primary production
National Category
Earth and Related Environmental Sciences Ecology
Identifiers
urn:nbn:se:umu:diva-56202 (URN)10.1111/j.1461-0248.2012.01762.x (DOI)000303666200003 ()
Available from: 2012-06-12 Created: 2012-06-12 Last updated: 2018-06-08Bibliographically approved
Vincent, A. G., Schleucher, J., Gröbner, G., Vestergren, J., Persson, P., Jansson, M. & Giesler, R. (2012). Changes in organic phosphorus composition in boreal forest humus soils: the role of iron and aluminium. Biogeochemistry, 108(1-3), 485-499
Open this publication in new window or tab >>Changes in organic phosphorus composition in boreal forest humus soils: the role of iron and aluminium
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2012 (English)In: Biogeochemistry, ISSN 0168-2563, E-ISSN 1573-515X, Vol. 108, no 1-3, p. 485-499Article in journal (Refereed) Published
Abstract [en]

Organic phosphorus (P) is an important component of boreal forest humus soils, and its concentration has been found to be closely related to the concentration of iron (Fe) and aluminium (Al). We used solution and solid state 31P NMR spectroscopy on humus soils to characterize organic P along two groundwater recharge and discharge gradients in Fennoscandian boreal forest, which are also P sorption gradients due to differences in aluminium (Al) and iron (Fe) concentration in the humus. The composition of organic P changed sharply along the gradients. Phosphate diesters and their degradation products, as well as polyphosphates, were proportionally more abundant in low Al and Fe sites, whereas phosphate monoesters such as myo-, scyllo- and unknown inositol phosphates dominated in high Al and Fe soils. The concentration of inositol phosphates, but not that of diesters, was positively related to Al and Fe concentration in the humus soil. Overall, in high Al and Fe sites the composition of organic P seemed to be closely associated with stabilization processes, whereas in low Al and Fe sites it more closely reflected inputs of organic P, given the dominance of diesters which are generally assumed to constitute the bulk of organic P inputs to the soil. These gradients encompass the broad variation in soil properties detected in the wider Fennoscandian boreal forest landscape, as such our findings provide insight into the factors controlling P biogeochemistry in the region but should be of relevance to boreal forests elsewhere.

Place, publisher, year, edition, pages
Springer, 2012
Keywords
Solution 31P NMR spectroscopy, Solid state 31P NMR, Sorption, Groundwater discharge, Groundwater recharge, Betsele
National Category
Earth and Related Environmental Sciences
Identifiers
urn:nbn:se:umu:diva-44955 (URN)10.1007/s10533-011-9612-0 (DOI)000300659300031 ()
Available from: 2011-06-15 Created: 2011-06-15 Last updated: 2018-06-08Bibliographically approved
Vestergren, J., Vincent, A. G., Jansson, M., Persson, P., Istedt, U., Gröbner, G., . . . Schleucher, J. (2012). High resolution characterization of organic phosphorus in soil extracts using 2D 1H-31P NMR correlation spectroscopy. Environmental Science and Technology, 46(7), 3950-3956
Open this publication in new window or tab >>High resolution characterization of organic phosphorus in soil extracts using 2D 1H-31P NMR correlation spectroscopy
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2012 (English)In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, no 7, p. 3950-3956Article in journal (Refereed) Published
Abstract [en]

Organic phosphorus (P) compounds represent a major component of soil P in many soils and are key sources of P for microbes and plants. Solution NMR (nuclear magnetic resonance spectroscopy) is a powerful technique for characterizing organic P species. However, <sup>31</sup>P NMR spectra are often complicated by overlapping peaks, which hampers identification and quantification of the numerous P species present in soils. Overlap is often exacerbated by the presence of paramagnetic metal ions, even if they are in complexes with EDTA following NaOH/EDTA extraction. By removing paramagnetic impurities using a new precipitation protocol, we achieved a dramatic improvement in spectral resolution. Furthermore, the obtained reduction in line widths enabled the use of multi-dimensional NMR methods to resolve overlapping <sup>31</sup>P signals. Using the new protocol on samples from two boreal humus soils with different Fe contents, two-dimensional <sup>1</sup>H-<sup>31</sup>P correlation spectra allowed unambiguous identification of a large number of P species based on their <sup>31</sup>P and <sup>1</sup>H chemical shifts and their characteristic coupling patterns, which would not have been possible using previous protocols. This approach can be used to identify organic P species in samples from both terrestrial and aquatic environments, increasing our understanding of organic P biogeochemistry.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2012
National Category
Environmental Engineering Environmental Sciences related to Agriculture and Land-use
Identifiers
urn:nbn:se:umu:diva-53091 (URN)10.1021/es204016h (DOI)000302850400048 ()22394413 (PubMedID)
Available from: 2012-03-13 Created: 2012-03-13 Last updated: 2018-06-08Bibliographically approved
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