| 1. |
- Berglund, Björn, et al.
(författare)
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Efficient removal of antibiotics in surface-flow constructed wetlands, with no observed impact on antibiotic resistance genes
- 2014
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Ingår i: Science of the Total Environment. - Amsterdam : Elsevier. - 0048-9697 .- 1879-1026. ; 476-477, s. 29-37
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Tidskriftsartikel (refereegranskat)abstract
- Recently, there have been growing concerns about pharmaceuticals including antibiotics as environmental contaminants. Antibiotics of concentrations commonly encountered in wastewater have been suggested to affect bacterial population dynamics and to promote dissemination of antibiotic resistance. Conventional wastewater treatment processes do not always adequately remove pharmaceuticals causing environmental dissemination of low levels of these compounds. Using constructed wetlands as an additional treatment step after sewage treatment plants have been proposed as a cheap alternative to increase reduction of wastewater contaminants, however this means that the natural microbial community of the wetlands becomes exposed to elevated levels of antibiotics. In this study, experimental surface-flow wetlands in Sweden were continuously exposed to antibiotics of concentrations commonly encountered in wastewater. The aim was to assess the antibiotic removal efficiency of constructed wetlands and to evaluate the impact of low levels of antibiotics on bacterial diversity, resistance development and expression in the wetland bacterial community. Antibiotic concentrations were measured using liquid chromatography-mass spectrometry and the effect on the bacterial diversity was assessed with 16S rRNA-based denaturing gradient gel electrophoresis. Real-time PCR was used to detect and quantify antibiotic resistance genes and integrons in the wetlands, during and after the exposure period. The results indicated that the antibiotic removal efficiency of constructed wetlands was comparable to conventional wastewater treatment schemes. Furthermore, short-term treatment of the constructed wetlands with environmentally relevant concentrations (i.e. 100-2000 ng x 1(-1)) of antibiotics did not significantly affect resistance gene concentrations, suggesting that surface-flow constructed wetlands are well-suited for wastewater treatment purposes. (c) 2014 Elsevier B.V. All rights reserved.
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| 2. |
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| 3. |
- Bodin, Hristina, et al.
(författare)
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Attenuation of pharmaceutical substances : phytoremediation using constructed wetlands
- 2018
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Ingår i: 13th Society of Wetland Scientists (SWS) Europe Chapter Meeting. ; , s. 19-22
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: Currently, wastewater treatment plants (WWTPs) do not efficiently remove pharmaceutical substances (PS). Thus, such substances are now frequently found in aquatic ecosystems worldwide. Also, concentrations of some PS in treated effluents exceed Environmental Quality Standards proposed by EU legislation. One resource-efficient option for increasing PS removal in WWTP effluents is to use constructed wetlands (CWs) as an attenuation step (Breitholtz et al. 2012; Li et al. 2014). However, very little research has been done on how to maximize the PS attenuation capacity of CWs. Therefore, a project with the aim to investigate reduction of different pharmaceutical substances in CWs with different vegetation compositions and water depths, was performed at the Experimental Wetland Area (EVA) located 20 km north of Halmstad, Sweden.
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| 4. |
- Bodin, Hristina, et al.
(författare)
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Tracer behaviour and analysis of hydraulics in experimental free watersurface wetlands
- 2012
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Ingår i: Ecological Engineering. - Amsterdam : Elsevier BV. - 0925-8574 .- 1872-6992. ; 49, s. 201-211
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Tidskriftsartikel (refereegranskat)abstract
- Effects of inlet design and vegetation type on tracer dynamics and hydraulic performance were investigated using lithium chloride in 18 experimental free water surface wetlands. The wetlands received similar water flow but had different vegetation types: 6 emergent vegetation wetlands (EVWs), 6 submerged vegetation wetlands (SVWs) and 6 free development wetlands (FDWs). Two types of inlet designs were applied: half of each wetland vegetation type had a barrier near the inlet to help distribute incoming tracer solution, while the rest had no barrier. Residence time distribution (RTD) functions were calculated from tracer data using two techniques: method of moments and a novel Gauss modelling approach. RTD functions were used to quantify hydraulic parameters: active wetland volume (e-value), water dispersion (N-value) and hydraulic efficiency (λ-value).For wetlands without barrier, significantly lower tracer mass recoveries were found from EVWs compared to FDWs and SVWs, signifying a risk of tracer methodological problems in small densely vegetated wetlands. These problems were minimized in wetlands with an inflow construction promoting distribution of incoming tracer solution.Compared to the method of moments, Gauss modelling seemed to produce more reliable λ-values but less reliable N-values. Data for precise hydraulic quantification were lost by Gauss modelling, as indicated by overall lower variance in these data sets and lower mass recoveries. However, Gauss modelling may minimize uncertainties associated with lithium immobilization/mobilization. Parameters were significantly affected by the RTD data analysis method, showing that the choice of method could affect evaluation of wetland hydraulics.The experimental wetlands in this study exhibited relatively high e-values and low N-values. This was probably caused by the small size of the wetlands and low water flow velocities, emphasizing that hydraulic parameter values obtained in small experimental wetlands may not be applicable to hydraulics in larger wetlands.The method of moments revealed lower e-values from EVWs compared to SVWs and FDWs. It was indicated that lower e-values were mainly caused by vegetation volumes. This highlighted a need for regular maintenance to secure efficient treatment volume in wetlands with dense vegetation.
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| 5. |
- Bodin, Hristina, 1977-
(författare)
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Wastewater treatment in constructed wetlands : Effects of vegetation, hydraulics and data analysis methods
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Degradation of water resources has become one of the most pressing global concerns currently facing mankind. Constructed Wetlands (CWs) represent a concept to combat deterioration of water resources by acting as buffers between wastewater and receiving water bodies. Still, constructing wetlands for the sole purpose of wastewater treatment is a challenging task. To contribute to this research area, the fundamental question raised in this doctorate thesis was: how do factors such as vegetation and residing water movements (hydraulics) influence wastewater treatment in CWs? Also, effects of different data analysis methods for results of CW hydraulics and wastewater treatment were investigated. Research was focused on phosphorus (P), ammonium-nitrogen (NH4+-N) and solids (TSS) in wastewater and o n P in macrophyte biomass. Studies were performed in pilot-scale free water surface (FWS) CW systems in Kenya (Chemelil) and Sweden (Halmstad) and as computer simulations.Results from the Chemelil CWs demonstrated that meeting effluent concentration standards simultaneously for all water quality parameters in one CW was difficult. Vegetation harvest, and thus nutrient uptake by young growing macrophytes, was important for maintaining low effluents of NH4+-N and P, especially during dry seasons. On the other hand, mature and dense vegetation growing for at least 4 months secured meeting TSS standards. Phosphorus in above-ground green biomass accounted for almost 1/3 of the total P mass removal, demonstrating high potential for P removal through macrophyte harvest in CWs. Also, results suggested that harvest should be species-specific to achieve high P removal by macrophytes and overall acceptable wastewater treatment in CWs. Still, different methods to estimate evapotranspiration (ET) from the Chemelil CWs showed that water balance calculations greatly impacted estimations of wastewater treatment results.Hydraulic tracer studies performed in the Chemelil and Halmstad CWs showed that mature and dense emergent vegetation in CWs could reduce effective treatment volumes (e-values), which emphasized the importance of regulating this type of vegetation. Also, it was shown that hydraulic tracer studies with lithium chloride performed in CWs with dense emergent vegetation had problems with low tracer recoveries. This problem could be reduced by promoting the distribution of incoming tracer solution into the CW using a barrier near the CW inlet pipe. Computer simulation results showed that the choice of tracer data analysis method greatly influenced quantifications of CW hydraulics and pollutant removal. The e-value could be 50% higher and the pollutant removal 13% higher depending upon used method. Moreover, unrealistic evalues (above 100%) in published literature could to some extent be explained by tracer data analysis method. Hence, to obtain more reliable hydraulic data and wastewater treatment results from CWs, more attention should be paid to the choice of tracer data analysis method.
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| 6. |
- Brönmark, Christer, et al.
(författare)
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Decoupling of cascading trophic interactions in a freshwater, benthic food chain
- 1996
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Ingår i: Oecologia. - Heidelberg, Germany : Springer Berlin/Heidelberg. - 0029-8549 .- 1432-1939. ; 108:3, s. 534-541
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Tidskriftsartikel (refereegranskat)abstract
- Food chain theory provides explicit predictions for equilibrium biomasses among trophic levels in food chains of different lengths. Empirical studies on freshwater benthic food chains have typically been performed on chains with up to three levels and in field experiments with limited spatial and temporal scale. Here we use a ‘’natural snapshot experiment” approach to study equilibrium biomass and abundance among trophic levels in natural ponds differing only with respect to fish assemblage structure. Forty-four ponds were surveyed for their density and biomass of fish, snails and periphyton. Ponds were divided into three categories based on fish assemblage: ponds with no fish (two trophic levels), ponds with molluscivorous fish (three trophic levels), ponds with molluscivorous fish (three trophic levels) and ponds that also had piscivorous fish (four trophic levels). Ponds without fish had a high density and biomass of snails and a low biomass of periphyton, whereas snails with molluscivorous fish. In the presence of piscivores, molluscivore populations consisted of low numbers of large individuals. Snail assemblages in piscivore ponds were characterised by relatively high densities of small-bodied detritivorous species and periphyton biomass was not significantly different from ponds with three trophic levels. Thus, predictions from classic food chain theory were upheld in ponds with up to three trophic levels. In ponds with four trophic levels, however, there was a decoupling of the trophic cascade at the piscivore-molluscivore level. Gape-limited piscivory, predation on snails by molluscivores that have reached an absolute size refuge from predation, and changes in food preferences of the dominant snails are suggested to explain the observed patterns.
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| 7. |
- Brönmark, Christer, et al.
(författare)
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Indirect effects of fish community structure on submerged vegetation in shallow, eutrophic lakes : an alternative mechanism
- 1992
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Ingår i: Hydrobiologia. - Dordrecht : Springer Netherlands. - 0018-8158 .- 1573-5117. ; 243/244:1, s. 293-301
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Tidskriftsartikel (refereegranskat)abstract
- The loss of submerged macrophytes during eutrophication of shallow takes is a commonly observed phenomenon. The proximate reason for this decline is a reduction of available light due to increasing phytoplankton and/or epiphyton biomass. Here we argue that the ultimate cause for the transition from a macrophyte-dominated state to a phytoplankton-dominated state is a change in fish community structure. A catastrophic disturbance event (e.g. winterkill) acting selectively on piscivores, cascades down food chains, eventually reducing macrophyte growth through shading by epiphyton, an effect that is reinforced by increasing phytoplankton biomass. The transition back from the phytoplankton to the macrophyte state depends on an increase in piscivore standing stock and a reduction of planktivores. A conceptual model of these mechanisms is presented and supported by literature data and preliminary observations from a field experiment. © 1992 Kluwer Academic Publishers.
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| 8. |
- Choudhury, Maidul I., et al.
(författare)
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Enhancing nitrogen removal through macrophyte harvest and installation of woodchips-based floating beds in surface-flow constructed wetlands
- 2024
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Ingår i: Chemosphere. - Oxford : Elsevier. - 0045-6535 .- 1879-1298. ; 359
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Tidskriftsartikel (refereegranskat)abstract
- Wetland management maintains nitrogen (N) removal capacity in mature and overgrown constructed wetlands (CWs). We evaluated whether CW management by macrophyte harvesting, and subsequent installation of woodchips-based floating beds (WFBs) planted with Glyceria maxima and Filipendula ulmaria improved N removal. In sixteen heavily overgrown experimental CWs, we applied four treatments: i) only macrophyte harvesting, ii) 5% of the harvested-CW surface covered with WFBs, iii) 20% WFBs cover, and iv) a control treatment (heavily overgrown). N removal was determined in all wetlands at nine occasions. Plant biomass accrual, N assimilation, and denitrification genes nirS, nirK, nosZI and nosZII on plant roots and woodchips from WFBs were estimated. Macrophyte harvesting improved N removal of heavily overgrown CWs, whereas subsequent WFB installation only sometimes improved N removal. Mean N removal efficiencies (± standard deviation) overall were 41 ± 15 %, 45 ± 20 %, 46 ± 16 % and 27 ± 8.3 % for treatments i to iv, respectively. Relative biomass production, root length and root surface area for G. maxima (mean ± standard deviation: 234 ± 114 %, 40 ± 6.5 cm, 6308 ± 1059 cm2g-1, respectively) were higher than those for F. ulmaria (63 ± 86 %, 28 ± 12 cm, 3131 ± 535 cm2g-1, respectively) whereas biomass N assimilation was higher for F. ulmaria (1.8 ± 0.9 gNm−2 of WFB) than for G. maxima (1.3 ± 0.5 gNm−2 of WFB). Denitrification gene abundance was higher on plant roots than on woodchips while G. maxima hosted higher root denitrification gene abundance than F. ulmaria. We conclude that macrophyte harvesting improves N removal in heavily overgrown CWs. WFBs installation has the potential to support plant growth and denitrification in surface-flow constructed wetlands. Further studies need to evaluate the long-term effects of macrophyte harvesting and WFB installation on N removal in CWs. © 2024 The Authors
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| 9. |
- Choudhury, Maidul I., et al.
(författare)
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Enhancing wetland nitrogen removal through macrophyte harvest and installation of woodchips-based floating beds
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Constructed wetlands (CWs) remove nitrogen (N) more efficiently as wetlands age and vegetation establishes. However, when CWs become heavily overgrown and filled with plant litter and root mats, channels form and N removal declines. Here, management may maintain high N removal. We tested two CW management options 1) restoration through macrophyte harvesting including root mat removal, and 2) subsequent installation of woodchips-based floating beds (WFBs) to compensate macrophyte loss. In a field experiment, using 16 heavily overgrown experimental CWs, we applied four treatments: i) macrophyte harvesting, ii) macrophyte harvesting and 5% of the wetland surface covered with WFBs, iii) macrophyte harvesting and 20% WFB cover, and iv) a control treatment (heavily overgrown). WFBs were planted with Glyceria maxima and Filipendula ulmaria before installation. N removal efficiency, removal rate and removal rate coefficient ka were estimated on nine occasions. After the experiment, WFBs were removed and plant biomass accrual, N assimilation, and denitrification gene (nirS, nirK, nosZI and nosZII) abundance on plant roots and woodchips were studied.Macrophyte harvesting significantly improved N removal of heavily overgrown CWs, whereas WFBs installation only improved N removal in harvested treatments on some occasions. Both G. maxima and F. ulmaria grew well on WFBs. Relative biomass production, root length and root surface area were higher for G. maxima than for F. ulmaria whereas biomass N assimilation was higher for F. ulmaria. Denitrification gene abundance was higher on plant roots than on woodchips while G. maxima hosted higher root denitrification gene abundance than F. ulmaria. We conclude that macrophyte harvesting improves N removal in heavily overgrown CWs. Further long-term field studies are needed to precisely evaluate the contribution of WFBs to N removal in CWs.
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| 10. |
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| 11. |
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| 12. |
- Eller, Franziska, et al.
(författare)
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Biomethane yield from different European Phragmites australis genotypes, compared with other herbaceous wetland species grown at different fertilization regimes
- 2020
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Ingår i: Resources. - Basel : MDPI. - 2079-9276. ; 9:5
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Tidskriftsartikel (refereegranskat)abstract
- Phragmites australis, Typha latifolia, T. angustifolia and Arundo donax are tall wetland graminoids with the potential to replace fossil fuels under sustainable cultivation conditions. We investigated the biomethane (CH4) production of these four species, including four different genotypes of P. australis, which represent the high intraspecific diversity of European reed. All plants were grown under three different macronutrient supplies (no nutrients added, an equivalent of 75 kg N ha−1 year−1 added and an equivalent of 500 kg N ha−1 year−1 added). Biomethane production was measured in four independent batch digestion tests. Across all experiments, fertilization regime had little effect on CH4 yield, which was on average 222 ± 31 L kg−1 volatile solids (VS). The lowest yield was produced by T. angustifolia (140 L kgVS−1) receiving no nutrients, while the highest yield was produced by A. donax (305 L kgVS−1) in the highest nutrient treatment. The intraspecific diversity of P. australis did not affect biomethane production. All P. australis genotypes produced on average 226 ± 19 L CH4 kgVS−1, which, although high, was still lower than conventional biogas species. The biomass production of P. australis was less increased by fertilization than that of Typha sp. and A. donax, but all species had similar biomass without fertilization.
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| 13. |
- Eriksson, Peder G, et al.
(författare)
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An experimental study on effects of submersed macrophytes on nitrification and denitrification in ammonium-rich aquatic systems
- 1999
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Ingår i: Limnology and Oceanography. - Waco, United States : American Society of Limnology and Oceanography, Inc.. - 0024-3590 .- 1939-5590. ; 44:8, s. 1993-1999
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Tidskriftsartikel (refereegranskat)abstract
- We have examined the role of microbial communities on the surface of submersed macrophytes and in the underlying sediment for nitrification and denitrification in light and dark in NH(4)(+)-enriched microcosm systems using isotope pairing and dilution techniques. Potamogeton pectinatus L. and intact sediment cores were collected in a shallow reservoir receiving treated municipal wastewater and containing dense submersed vegetation. Chambers containing P. pectinatus shoots, sediment, or both P. pectinatus shoots and sediment were exposed to 6 h of darkness, 6 h of light, and 6 h of darkness. (14)NH(4)(+) and (15)NO(3)(-) were added at ambient concentrations of 15 and 5 mg N liter(-1), respectively. NH(4)(+) was primarily nitrified in the epiphytic microbial communities, and NO; was denitrified in the underlying sediment. In chambers containing macrophytes, there was a net production of O(2) and NO(3)(-) in light and a net consumption in dark, and nitrification was higher in light than in dark. In chambers with only sediment, there was always a net consumption of NO(3)(-), and nitrification was similar in light and dark. The results show that submersed macrophytes can be important for the N metabolism in NH(4)(+)-rich freshwaters (e.g., wastewater treatment systems) by stimulating nitrification through providing surfaces for attached nitrifying bacteria and possibly also through diurnal changes in the water chemistry.
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| 14. |
- Eriksson, Peder G., et al.
(författare)
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Functional differences in epiphytic microbial communities in nutrient-rich freshwater ecosystems : An assay of denitrifying capacity
- 1996
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Ingår i: Freshwater Biology. - Chichester, United Kingdom : Wiley-Blackwell. - 0046-5070 .- 1365-2427. ; 36:3, s. 555-562
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Tidskriftsartikel (refereegranskat)abstract
- 1. The denitrifying capacity of epiphyton was used to evaluate differences in the function of epiphytic microbial communities on submersed macrophytes in nutrient-rich freshwater ecosystems. The denitrifying capacity of epiphyton on Patamogeton perfoliatus shoots of different age and with different epiphytic abundances from a eutrophic lake was investigated in laboratory microcosms in the Light and dark. Additionally, differences between epiphyton on shoots of Potamogeton pectinatus grown under different in Situ nutrient and hydraulic conditions were investigated by examining their denitrifying capacity. 2. Denitrification was registered in well-developed epiphytic layers on both mature and senescent shoots in the dark, with activities 3- to 10-fold higher in the epiphytic communities of senescent shoots. No activity was detected on young shoots with sparse epiphyton or on shoots from which loosely attached epiphyton had been removed. Denitrification never occurred during illumination. 3. Even though the epiphytic abundance was similar in magnitude, the denitrifying capacity of epiphyton adapted to high nutrient loadings was about a hundred times higher than that of epiphyton adapted to lower nutrient levels. Additionally, epiphytic abundance and denitrifying capacity were higher at sites less exposed to wave turbulence or water currents, than at sites with more water turbulence. 4. The results illustrate how the hydraulic and nutrient conditions of the surrounding water affect both the quantity and function of epiphytic microbial communities in nutrient-rich freshwater ecosystems.
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| 15. |
- Eriksson, Peder G., et al.
(författare)
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Nitrogen removal in a wastewater reservoir : The importance of denitrification by epiphytic biofilms on submersed vegetation
- 1997
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Ingår i: Journal of Environmental Quality. - Madison, United States : American Society of Agronomy. - 0047-2425 .- 1537-2537. ; 26:3, s. 905-910
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to examine the importance of epiphytic denitrifying bacteria on submersed vegetation in removing N from a shallow nutrient-enriched freshwater ecosystem. The investigation was conducted during the summer of 1994 in a surface now reservoir receiving municipal tertiary-treated wastewater. The submersed vegetation in the reservoir was dominated by Potamogeton pectinatus L. and filamentous green algae (FGA). The N loading was 2300 mg N h(-1) m(-2) and the N removal, calculated as the mean difference between influent and effluent N, was 190 mg N h(-1) m(-2) (8%). The majority of influent N consisted of NH4+, but the main part of the N removal was due to the removal of NO3- whereas no net retention of NH4+ was found. Mean total soluble solids and BOD7 retention was 69 and 38%, respectively, Denitrification measurements were conducted in darkness at in situ temperature in microcosms with P. pectinatus, FGA, or infect sediment cores. Epiphytic denitrification ranged between 0.21 to 7.0 mg N h(-1) m(-2) reservoir surface area depending on the abundance of the submersed vegetation (5-140 g DW m(-2)). Sediment denitrification was 4.7 mg N h(-1) m-L reservoir surface area. The mean assimilative N uptake of the submersed vegetation and epiphyton was 3.4 and 1.6 mg N h(-1) m(-2) reservoir surface area, respectively. Measured N removal rates through plant uptake and denitrification could only account for a minor part of the N removal observed by mass balance. However, microcosm denitrification measurements underestimate actual denitrification. Thus, the major part of the N removal was most likely due to denitrification. In conclusion, this study indicates that denitrification in epiphytic microbial communities on submersed vegetation can be of significant importance for the N removal in nutrient-enriched freshwater ecosystems.
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| 16. |
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| 17. |
- Graneli, Wilhelm, et al.
(författare)
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Rhizome dynamics and resource storage in Phragmites australis
- 1992
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Ingår i: Wetlands Ecology and Management. - Dordrecht, Netherlands : Springer Netherlands. - 0923-4861 .- 1572-9834. ; 1:4, s. 239-247
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Tidskriftsartikel (refereegranskat)abstract
- Seasonal changes in rhizome concentrations of total nonstructural carbohydrates (TNC), water soluble carbohydrates (WSC), and mineral nutrients (N, P and K) were monitored in two Phragmites australis stands in southern Sweden. Rhizome biomass, rhizome length per unit ground area, and specific weight (weight/ length ratio) of the rhizomes were monitored in one of the stands. Rhizome biomass decreased during spring, increased during summer and decreased during winter. However, changes in spring and summer were small (< 500 g DW m-2) compared to the mean rhizome biomass (approximately 3000 g DW m-2). Winter losses were larger, approximately 1000 g DW m-2, and to a substantial extent involved structural biomass, indicating rhizome mortality. Seasonal changes in rhizome length per unit ground area revealed a rhizome mortality of about 30% during the winter period, and also indicated that an intensive period of formation of new rhizomes occurred in June. Rhizome concentrations of TNC and WSC decreased during the spring, when carbohydrates were translocated to support shoot growth. However, rhizome standing stock of TNC remained large (> 1000 g m-2). Concentrations and standing stocks of mineral nutrients decreased during spring/ early summer and increased during summer/ fall. Only N, however, showed a pattern consistent with a spring depletion caused by translocation to shoots. This pattern indicates sufficient root uptake of P and K to support spring growth, and supports other evidence that N is generally the limiting mineral nutrient for Phragmites. The biomass data, as well as increased rhizome specific weight and TNC concentrations, clearly suggests that "reloading" of rhizomes with energy reserves starts in June, not towards the end of the growing season as has been suggested previously. This resource allocation strategy of Phragmites has consequences for vegetation management. Our data indicate that carbohydrate reserves are much larger than needed to support spring growth. We propose that large stores are needed to ensure establishment of spring shoots when deep water or stochastic environmental events, such as high rhizome mortality in winter or loss of spring shoots due to late season frost, increase the demand for reserves. © 1992 SPB Academic Publishing.
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| 18. |
- Hansson, Anna, et al.
(författare)
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Landowners' incentives for constructing wetlands in an agricultural area in south Sweden
- 2012
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Ingår i: Journal of Environmental Management. - London : Elsevier BV. - 0301-4797 .- 1095-8630. ; 113, s. 271-278
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Tidskriftsartikel (refereegranskat)abstract
- Eutrophication of the Baltic Sea has in Sweden led to the initiation of government schemes aiming to increase wetland areas in agricultural regions and thereby reduce nutrient transport to the sea. Landowners play a significant role as providers of this ecosystem service and are currently offered subsidies to cover their costs for constructing and maintaining wetlands. We undertook a grounded theory study, in which landowners were interviewed, aiming at identifying landowners' incentives for constructing wetlands on their land. The study showed that adequate subsidies, additional services that the wetland could provide to the landowner, local environmental benefits, sufficient knowledge, and peers' good experiences could encourage landowners to construct wetlands. Perceived hindrances were burdensome management, deficient knowledge, time-consuming application procedures and unclear effectiveness of nutrient reduction. The main reason for not creating a wetland, however, was that the land was classified as productive by the landowner, i.e., suitable for food production. Current schemes are directed toward landowners as individuals and based on subsidies to cover costs. We propose that landowners instead are approached as ecosystem service entrepreneurs and contracted after a tendering process based on nutrient reduction effects. This would lead to new definitions of production and may stimulate improved design and placement of wetlands. (C) 2012 Elsevier Ltd. All rights reserved.
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| 19. |
- Hansson, Anna M., 1984-, et al.
(författare)
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Barriers and drivers for sustainable business model innovation based on a radical farmland change scenario
- 2023
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Ingår i: Environment, Development and Sustainability. - Dordrecht : Springer. - 1387-585X .- 1573-2975. ; 25:8, s. 8083-8106
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Tidskriftsartikel (refereegranskat)abstract
- The agricultural sector has a critical role in creating social and environmental value of natural resources in addition to its traditional role of creating economic value by supplying food to the ever-increasing world population. In fulfilling this dual role, the agricultural sector often faces competing pressures: to operate financially profitable businesses and to create, maintain, and benefit from ecosystem services (ES) in their operations. This paper analyses these pressures in an examination of drivers and barriers to the initiation of the business model innovation process for sustainability (BMIpfS) as perceived by ten agricultural business managers who operate farms in southern Sweden. The paper explores the interplay between managerial cognition and business decisions as revealed in semi-structured interviews. The new ES in focus connect to radical land-use change, paludiculture, as used in the rewetting of farmland intended to reduce the greenhouse gas emissions that drained peat soil causes. The paper contributes to the literature by identifying drivers and barriers that moderates the initiation of the BMIpfS. Although the managers acknowledge the importance of long-term, sustainable social, and environmental value creation, they have grave doubts about the profitability of activities associated with the preservation of peat soils and connected ES. These managers would benefit from taking a more proactive, long-term approach to business model changes for sustainability and from acquiring more knowledge about market demand for sustainability-oriented ES. Successful facilitation and implementation of knowledge transfer and government subsidies that support ES could improve the turning of profits based on sustainable value creation.
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| 20. |
- Hansson, Anna, 1984-, et al.
(författare)
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Markägares motiv för att anlägga våtmarker
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- För att minska näringsläckaget från jordbruksmark via vattendrag till havet ges i Sverige bidrag till privata markägare genom olika åtgärdsprogram. Målet har varit att erhålla 12 000 hektar anlagda våtmarker 2010. Målet kommer dock inte att uppnås. Ett av skälen kan vara att markägarna har andra motiv än ekonomiska när de väljer att anlägga, eller avstå från att anlägga, en våtmark. För att öka förståelsen för markägares syn på miljö, markanvändning och vattenförvaltning och att identifiera motiv för att anlägga våtmarker genomfördes en kvalitativ studie i södra Halland. Femton markägare intervjuades och deras svar analyserades i enlighet med metoden Grundad teori. Viktigast för markägarna var Att förvalta sin mark på bästa sätt vilket innebar att mark som var odlingsbar i första hand skulle användas för det ändamålet. Lågproduktiv mark kunde komma ifråga för våtmarksanläggande, men det var inte självklart. Att ta sitt miljöansvar innebar främst att följa regelverket, men kunde också omfatta frivilliga åtgärder för miljön. Det var dock nödvändigt Att främja företagets ekonomi. Markägarna hade goda Kunskaper och insikter om jordbrukets miljöbelastning, men efterlyste Stöd och bekräftelse. Att vara missgynnad av regelverket som ansågs gynna större jordbruk och jordbruk i andra länder var allmänt. Utifrån resultatet har rekommendationer utformats inför det fortsatta arbetet med att anlägga våtmarker på privat mark.
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| 21. |
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| 22. |
- Johannesson, Karin, 1982-
(författare)
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Analysis of phosphorus retention variations in constructed wetlands receiving variable loads from arable land
- 2011
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Seven wetlands, constructed on agricultural land in the south of Sweden, were investigated with respect to phosphorus (P) retention. The overall aim was to increase the understanding of P retention and find possible explanations for the variations in retention that have been observed in previous studies. This was done by i) investigating P retention in wetlands receiving various water and P loads, ii) investigating the effect of variations in water flow on P transport, iii) comparing how well retention estimates based on water quality data agreed with measurements of the amount of P accumulated in the sediment.Results showed that P retention was positive in all wetlands, but it was variable (1–58 kg ha-1 yr-1) and months with negative retention were observed in nearly all wetlands. Such monthly negative retention coincided with i) high flow periods, when particulate P was either flushed straight through the wetlands or resuspended from the bottoms, and ii) warm low flow periods, in which case dissolved P was probably released from wetland sediments due to anoxic conditions.The results from the two methods for estimating P retention differed. Based on water quality data, the total P load during four years was 65 kg ha-1 and the mean P retention 2.8 kg ha-1 yr-1, or 17% of the total P load. In contrast, the amount of P accumulated in the inlet zone alone amounted to 78% of the P load, and the P content in the upper sediment of the whole wetland area exceeded the P load with a factor four. This discrepancy showed the need to add studies of sediment accumulation to inflow-outflow estimates for an improved understanding of wetland P retention.
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| 23. |
- Johannesson, Karin M., 1982-, et al.
(författare)
-
Clay-bound phosphorus retention in wetlands : a catchment comparison
- 2010
-
Ingår i: 6th International Phosphorus Workshop (IPW6). ; , s. 127-127
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Ten constructed wetlands, situated in agricultural areas in the south of Sweden, are investigated for phosphorus (P) retention and factors affecting the efficiency. These wetlands are situated in areas dominated by clay or heavy clay soils. National monitoring and estimations have shown that agricultural areas dominated by such clay soils have among the highest phosphorus losses. It has also been shown that a large proportion of P is transported in particulate form; hence, it is expected that sedimentation is the predominant P retention process in the selected wetlands. Sedimentation of clay may, however, be difficult to achieve in wetlands, and the aim of the study is to quantify the function of wetlands as sinks for the P lost from the catchments. Sedimentation and accumulation of particles are measured once a year using sedimentation plates (40×40 cm) placed on the bottom of the wetlands. Additional sedimentation traps (estimating gross sedimentation) have been placed in three of the wetlands, and those are emptied two times per year. This paper presents results for P and soil retention after the first year (in kg P ha-1 year-1), estimated by extrapolating the amount of sediment accumulated on the plates, and the content of total phosphorus (TP), to the whole wetland area. Furthermore, one wetland was selected for a detailed investigation of the effect of a vegetation filter, which in a previous study has been shown to have a positive effect on particle retention. Here, estimates of net and gross sedimentation are measured before, within and after the vegetation filter. To identify some factors of significant importance for wetland P load and retention efficiency, the statistical relationship with different wetland and catchment characteristics is analyzed. The factors included are the ratio wetland area to catchment area, average hydraulic load, and various catchment characteristics, e.g. soil type, topography, fertilization history, and soil P fractions. Since there is some uncertainty regarding sedimentation of fine clay particles (< 0.2 m), the size fractions of the accumulated sediment is determined to see whether or not the finest clay particles from the catchments settle in the wetlands. Previous studies have shown a correlation between particle size and bioavailability, where finer clay particles contain larger proportion of easily available P. Trapping the finest clay particles is therefore of particular ecological importance and needs to be further investigated.
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| 24. |
- Johannesson, Karin M., 1982-, et al.
(författare)
-
Phosphorus and particle retention in constructed wetlands—A catchment comparison
- 2015
-
Ingår i: Ecological Engineering. - Amsterdam : Elsevier. - 0925-8574 .- 1872-6992. ; 80, s. 20-31
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract Seven constructed wetlands (0.05–0.69 ha), situated in agricultural catchments (22–267 ha) in the south of Sweden, were studied for two years with two aims: to (i) quantify their function as sinks for particles and phosphorus (P) lost from the catchments, and (ii) investigate to what degree catchment and wetland characteristics and modeled loads (using hydrochemical catchment models) could be used to explain differences in retention between the wetlands. The wetland areas ranged from 0.04 to 0.8% of the respective catchment area, and they were situated in areas dominated by fine-textured soils with relatively high P losses and the main proportion of P transported in particulate form. Net P and particle retention were estimated during two years from annual accumulation of particles on sedimentation plates (40 × 40 cm) on the bottom of the wetlands.There was an annual net retention of particles and P, but with a large variation (for particles 13–108 t ha−1 yr−1 and for P 11–175 kg ha−1 yr−1), both between wetlands and between years. The difference between the two years was larger than the difference in mean P retention between the seven wetlands. There was a positive relationship between P and particle retention and three catchment factors, i.e. P status (P-AL) of agricultural soils, average slope in the catchments and the livestock density, and a negative relationship with the agricultural soil clay content. In addition, there was a positive relationship with the wetland length:width ratio. Contrary to expectations, neither the modeled hydraulic load nor P load was significantly correlated with the measured particle and P retention. There was also a positive relationship between P concentration in the sediment and soil P status in the catchment. The results imply that considerable errors are introduced when down-scaling modeled regional nutrient losses to estimate the P loads to small wetlands in agriculturally dominated catchments. A more qualitative approach, using catchment characteristics for identification of hot-spot fields, may be equally good to identify suitable locations for constructed wetlands to reduce diffuse P loads. © 2014 Elsevier B.V.
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| 25. |
- Johannesson, Karin, 1982-
(författare)
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Particulate phosphorus accumulation and net retention in constructed wetlands receiving agricultural runoff : Critical analysis of factors affecting retention estimates
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Övergödning är ett allvarligt miljöproblem, som bland annat orsakar omfattande blomningar av alger och blågrönbakterier. I söt- och brackvatten är fosfor ofta det mest begränsande näringsämnet för dessa organismer, varför en minskning av fosfortillförseln är nödvändig för att nå förbättringar. I Sverige beräknas jordbruket bidra med 44 % av fosforbelastningen till Egentliga Östersjön, och olika åtgärder för att minska fosforförlusterna från jordbruksmark tillämpas runtom i Sverige.Våtmarker anläggs ofta för att fånga näringsämnen och partiklar från jordbruksmark innan de läcker ut i vattendrag och slutligen i Östersjön. Tidigare utvärderingar av anlagda våtmarker i Sverige har visat på en varierande och relativt låg fastläggning av fosfor. Osäkerheten kring dessa utvärderingar är dock ganska hög, och bottnar i kunskapsluckor både vad gäller processer för fastläggning och transport av fosfor från mindre jordbruksområden. I denna avhandling utreds därför hur anlagda våtmarker fungerar som fällor för jordpartiklar och partikelbunden fosfor i områden med höga fosforförluster.Sju anlagda våtmarker i jordbruksområden med mycket lerjordar studerades, och mängden fosfor och partiklar som fastlades på botten varierade mycket mellan olika våtmarker (13-108 ton partiklar/ha/yr och 11-175 kg fosfor/ha/yr). De faktorer i området uppströms som var kopplade till fosforfastläggning var lutningen i området, markens lerhalt och innehåll av växttillgänglig fosfor samt områdets djurtäthet.Resultat från fyra våtmarker visade på en hög resuspension (partiklar från botten virvlas tillbaka upp i vattnet), men en del av de uppvirvlade partiklarna kom troligtvis från erosion från våtmarkernas sidor och inte från det material som fastlades på botten. Man såg även indikationer på resuspension från vattenprover tagna i utloppet av en annan våtmark. Där var partikelbunden fosfor klart dominerande, vilket kan ha varit en konsekvens av resuspension från botten.Variationerna av fosforkoncentrationer vid in- och utlopp i sju anlagda våtmarker studerades, för att kritiskt kunna granska tidigare retentionsskattningar. Det var stora variationer i sambanden mellan vattenflöde och fosforkoncentrationer mellan de olika våtmarkerna. De faktorer som påverkade sambandet mellan flöde och koncentration var 1) om det var varm eller kall årstid (d v s sommar eller vinter), 2) om det var högt eller lågt vattenflöde, samt 3) om inflödet bestod av ett dräneringsrör eller ett öppet dike/åfåra. I våtmarker med öppet dike som inflöde var flödes-koncentrationssambandet av totalfosfor negativt vid låga flöden och positivt vid höga flöden. De olika sambanden visar hur viktig sättet att provta vatten är, då inkommande mängd fosfor både kan över- och underskattas om man inte är medveten om sådana variationer. Vid automatisk provtagning styrd av flödesmätningen sker detta ofta i utloppet, men eftersom vattnet har en viss uppehållstid i våtmarken (speciellt sommartid) kan retentionsberäkningen påverkas av att all provtagningen styrs av flödet i utloppet. För att identifiera vilka områden som bidrar med mest näring och partiklar valdes ett stort område dominerat av jordbruksmark ut – för att undersöka hur man skulle kunna bedöma var anlagda våtmarker skulle kunna göra mest nytta. Området delades in i tio mindre områden, och vattenprover samlades in från diken och åfåror. Resultaten visade på stora skillnader i fosfordynamik mellan olika delområden med olika jordtyper, trots att de hade liknande markanvändning. Det fanns ofta en koppling mellan höga fosforkoncentrationer i vattnet och en hög andel lerjordar i området. För partiklar fanns det en tendens till samband mellan höga koncentrationer och hög andel vinterbar mark. En anlagd våtmark skulle antagligen ha högst effekt om den placerades nedströms områden som är känsliga för erosion – områden med hög andel lerjordar eller med hög andel vinterbar mark.
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| 26. |
- Johannesson, Karin, 1982-, et al.
(författare)
-
Phosphorus load variations and retention in non-point source wetlands in southern Sweden
- 2011
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Data from seven constructed wetlands receiving runoff from agricultural catchments in the south of Sweden were investigated with respect to phosphorus (P) retention. The seven wetlands differed in size (0.22-2 ha), design, land use and catchment characteristics. The hydraulic load varied between 7 and 725 m yr-1, which reflect the different geographical and hydrological conditions. The overall aim of this study was to increase the understanding of how water flow and inflow P concentration varations affect the P retention in constructed wetlands receiving runoff from arable land. Water flow was measured continuously, and time or flow proportional water samples were taken. Grab samples were taken during high flow periods and also to supplement the automatic water sampling. P retention varied between wetlands, from 1 to 58 kg ha-1 yr-1, and was correlated to the P load (R2=0.9, p<0.05). P retention in the wetlands varied strongly between years, and negative retention was recorded for some years and wetlands. When investigating monthly retention for each wetland, release of P corresponded to either high flow or possible anoxic conditions during low-flow periods in summer or during winter when ice covered the wetlands. Analyses of grab samples revealed a relationship between TP concentration and water flow for most wetlands. In some wetlands, P was transported mainly as particulate P (PP), but in other wetlands, soluble P was the dominating form in both inflow and outflow. Incoming concentrations varied greatly between wetlands (1-2000 μg l-1) which reflected the different catchment characteristics, e.g. land use, soil type and topography.
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| 27. |
- Johannesson, Karin, 1982-, et al.
(författare)
-
Phosphorus load variations and retention in non-point source wetlands in southern Sweden
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Data from seven constructed wetlands receiving runoff from agricultural catchments in the south of Sweden were investigated with respect to phosphorus (P) retention. The seven wetlands differed in size (0.22-2 ha), design, land use and catchment characteristics. The hydraulic load varied between 7 and 725 m yr-1, which reflect the different geographical and hydrological conditions. The overall aim of this study was to increase the understanding of how water flow and inflow P concentration varations affect the P retention in constructed wetlands receiving runoff from arable land. Water flow was measured continuously, and time or flow proportional water samples were taken. Grab samples were taken during high flow periods and also to supplement the automatic water sampling. P retention varied between wetlands, from 1 to 58 kg ha-1 yr-1, and was correlated to the P load (R2=0.9, p<0.05). P retention in the wetlands varied strongly between years, and negative retention was recorded for some years and wetlands. When investigating monthly retention for each wetland, release of P corresponded to either high flow or possible anoxic conditions during low-flow periods in summer or during winter when ice covered the wetlands. Analyses of grab samples revealed a relationship between TP concentration and water flow for most wetlands. In some wetlands, P was transported mainly as particulate P (PP), but in other wetlands, soluble P was the dominating form in both inflow and outflow. Incoming concentrations varied greatly between wetlands (1-2000 μg l-1) which reflected the different catchment characteristics, e.g. land use, soil type and topography.
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| 28. |
- Johannesson, Karin, 1982-, et al.
(författare)
-
Temporal phosphorus dynamics affecting retention estimates in agricultural constructed wetlands
- 2017
-
Ingår i: Ecological Engineering. - Amsterdam : Elsevier. - 0925-8574 .- 1872-6992. ; 103, s. 436-445
-
Tidskriftsartikel (refereegranskat)abstract
- Data from seven constructed wetlands (CWs) in the south of Sweden were analyzed to investigate the effects of water flow and season on inflow phosphorus (P) concentrations and temporal P retention variations in CWs receiving runoff from arable land. The form of P (dissolved or particulate) during different water flows (high and low) and seasons (warm and cold) was investigated using the results of total P (TP) and phosphate analyzed in grab samples that had been collected regularly or occasionally during two to nine years, along with continuous water flow measurements.The form of inflow and outflow P (particulate or dissolved P) differed between CWs, and also varied with season and flow. For instance, in three of the CWs, particulate P (PP) dominated the inflow during the cold period with high flow, while during the other periods the proportion of PP was approximately 50%. In one CW situated in a catchment with high clay content, PP dominated both inflow and outflow at all times. The average clay content in catchment top soils was positively correlated to the flow-weighted inflow TP concentrations.In three CWs receiving runoff through drainage pipes, the relationship between TP concentrations (TPin) and water flow was positive, both during high and low flow, and during warm and cold period. However, in four CWs that received surface water runoff, the relationship between TPin and water flow was positive during high flow periods (i.e. the 25% sampling occasions with the highest flow), and during low flow and warm period, the relationship was negative in these four wetlands, indicating either anoxic stagnant water upstream or influence from rural wastewater.The temporal dynamics of P concentrations mean that in some of the CWs, the main part of the annual P retention may occur during a few days with high water flows. The correlation between concentration and water flow suggests that the water sampling strategy may have a considerable impact on retention estimates, as exemplified by some calculation examples.
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| 29. |
- Johansson, Jörgen, 1958-, et al.
(författare)
-
Slututvärdering av det svenska landsbygdsprogrammet 2007–2013 : DELRAPPORT IV : Synteser för en hållbar landsbygdsutveckling : Utvärdering av programmets samlade effekter
- 2017. - 1
-
Rapport (refereegranskat)abstract
- Denna rapport är en del av utvärderingen av landsbygdsprogrammet 2007–2013. Fyra grupper med forskare från universitet och högskolor har gjort slututvärderingen. Den publiceras i fyra delrapporter varav detta är en. Frågor som handlar om hela programmet besvaras huvudsakligen i delrapport IV. Frågor om enskilda åtgärder besvaras i de tre andra delrapporterna. En översikt av vilka frågor som besvaras i vilken rapport finns på följande sidor.Slututvärderingen görs för att besvara EU-gemensamma och specifika svenska utvärderingsfrågor om vilka effekter programmet har haft, i vilken utsträckning det har bidragit till att uppfylla målen och hur effektivt detta har gjorts.Utvärderingssekretariatet vid Jordbruksverket ansvarar för att de svenska EU-programmen där Jordbruksverket är förvaltande myndighet blir utvärderade. Det innebär att utvärderingssekretariatet beställer och genomför utvärderingar av landsbygdsprogrammet, havs- och fiskeriprogrammet samt programmet för lokalt ledd utveckling inom regionalfonden och socialfonden. Programmen utvärderas dels var för sig men också tillsammans. Utvärderingarna görs i relation till målen i programmen och de övergripande EU 2020-målen.De flesta utvärderingarna genomförs av externa aktörer. Vi tar hjälp av forskare för att kvalitetsgranska rapporterna innan de publiceras. I slutet av rapporterna finns ett utlåtande från granskarna. Rapporterna publiceras i en särskild rapportserie och rapportförfattarna är ansvariga för slutsatserna. Slutsatserna utgör inte Jordbruksverkets officiella ståndpunkt./Utvärderingssekretariatet vid Jordbruksverket
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| 30. |
- Johansson, Maria, et al.
(författare)
-
Assessing cultural ecosystem services as individuals’ place-based appraisals
- 2019
-
Ingår i: Urban Forestry & Urban Greening. - München : Elsevier. - 1618-8667 .- 1610-8167. ; 39, s. 79-88
-
Tidskriftsartikel (refereegranskat)abstract
- Though the existence of cultural ecosystem services is dependent on people’s activities and experiences, these services are still commonly assessed using top–down approaches. In this study, appraisal theory and research into human responses to natural environments formed the basis of a systematic multilevel investigation of appraisals of created wetland areas. The aim was to explore how appraisals could be used as a bottom–up approach to assessing the perceived contribution of wetland areas s to people’s quality of life (QoL). In total, 111 participants assessed environmental perceptions, affective experiences, and restorative potentials on site at three wetlands in Sweden. The results indicate that wetland areas and specific places with different ecological functions within these areas were appraised significantly differently. Moreover these places were perceived to support various QoL aspects to different degrees. Concepts and methods tested here give environmental planners hands-on tools for facilitating communication with expected users about the cultural ecosystem services of created wetland areas. © 2019
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| 31. |
- Kallner Bastviken, Sofia, et al.
(författare)
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Effects of vegetation and hydraulic load on seasonal nitrate removal in treatment wetlands
- 2009
-
Ingår i: Ecological Engineering. - Amsterdam : Elsevier. - 0925-8574 .- 1872-6992. ; 35:5, s. 946-952
-
Tidskriftsartikel (refereegranskat)abstract
- Optimising nitrate removal and identifying critical factors for nitrate removal in wetlands is an important environmental task in the effort to achieve better surface water quality. In this study, eighteen free water surface wetlands with similar shape and size (22 m2 each) received groundwater with a high nitrate-N concentration (about 11 mg l−1). The effects of two hydraulic loads, 0.13 m d−1 and 0.39 m d−1, and three vegetation types – emergent, submersed and freely developing vegetation – on the nitrate-N removal were investigated through mass inflow and outflow measurements.No significant difference in nitrate removal between the different hydraulic loads could be detected. Significantly higher area-specific nitrate removal and first-order area-based rate coefficients were found in the basins with emergent vegetation, with no difference between the basins with submersed and freely developing vegetation. The nitrate-N removal increased as the wetlands matured and the vegetation grew denser, emphasizing the role of dense emergent vegetation for nitrate removal at high nitrate concentrations.
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| 32. |
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| 33. |
- Martens, Mireille, et al.
(författare)
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The greenhouse gas emission effects of rewetting drained peatlands and growing wetland plants for biogas fuel production
- 2021
-
Ingår i: Journal of Environmental Management. - Amsterdam : Elsevier. - 0301-4797 .- 1095-8630. ; 277
-
Tidskriftsartikel (refereegranskat)abstract
- Efforts to mitigate greenhouse gas (GHG) emissions are receiving increased attention among governmental and commercial actors. In recent years, the interest in paludiculture, i.e. the use of rewetted peatlands, has grown because of its potential to reduce GHG emissions by stopping soil decomposition. Moreover, cultivating wetland plants on rewetted peatlands for bioenergy production that replaces fossil fuels in the transport sector, can contribute to additional GHG emission reductions. In this study, an analysis of literature data was conducted to obtain data on GHG emissions (CO2 and CH4) and biomass production from rewetted peatlands cultivated with two different wetland plant species: Phragmites australis (Pa) and Typha latifolia (Tl). In addition, a biogas experiment was carried out to investigate the biomethane yield of Pa and Tl biomass, and the reduction of global warming potential (GWP) by using biomethane as vehicle fuel. The results show that peatland rewetting can be an important measure to mitigate the GWP as it reduces GHG emissions from the soil, particularly on a 100-year timescale but also to some extent on a 20-year timescale. More specifically, rewetting of 1 km2 of peatland can result in a GWP reduction corresponding to the emissions from ±2600 average sized petrol cars annually. Growing Pa on rewetted peatlands reduces soil GHG emissions more than growing Tl, but Pa and Tl produced similar amounts of biomass and biomethane per land area. Our study concludes that Pa, because of a more pronounced GWP reduction, is the most suitable wetland plant to cultivate after peatland rewetting. © 2020 The Author(s). Published by Elsevier Ltd.
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| 34. |
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| 35. |
- Milenkovski, Susann, et al.
(författare)
-
Composition of denitrifying bacterial enzyme genes nirS, nirK and nosZ in constructed wetlands
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this study the composition of the denitrifying bacterial community among constructed wetlands in agricultural areas was investigated. Thirty-two constructed wetlands located in Southern Sweden were surveyed, and biofilm samples from each were analyzed by applying denaturing gradient gel electrophoresis, to investigate the community composition of the three denitrifying bacterial enzyme genes nirK, nirS and nosZ. The DNA sequences of the enzyme genes were compared to known DNA sequences in GeneBank using BLAST. The results of the denitrifying bacterial enzyme genes indicated that these habitats may harbour a heterogeneous denitrifying bacterial community. Individual analysis of the enzyme genes revealed that nirS was more heterogeneous than both nirK and nosZ. Most sequences from the present study clustered with known sequences from species belonging to the group of α-Proteobacteria, and to a lesser extent with β- Proteobacteria and γ-Proteobacteria, and only nirS clustered with a member of gram-positive bacteria.
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| 36. |
- Milenkovski, S, et al.
(författare)
-
Denitrification in constructed wetlands in southern Sweden
- 2007
-
Ingår i: 2nd International Symposium on Wetland Pollutant Dynamics and Control - WETPOL 2007. - : Institute of Geography. - 9789949116881 - 9949116880 - 9789949116898 - 9949116899 ; , s. 220-222
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 37. |
- Milenkovski, Susann, et al.
(författare)
-
Variation of eubacterial and denitrifying bacterial biofilm communities among constructed wetlands
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Bacteria play important roles in the transformation of nutrients in wetlands, but few studies have examined parameters affecting variation in bacterial community composition between wetlands. We compared the composition of eubacterial and denitrifying bacterial biofilm communities in 32 agricultural constructed wetlands in southern Sweden, and the extent to which wetland environmental parameters could explain the observed variation. Structure and richness of the eubacterial 16S rRNA gene and three denitrifying bacterial enzyme genes (nirK, nirS and nosZ), analysed by molecular fingerprinting methods, varied among the constructed wetlands, which could be partly explained by different environmental parameters. Results from the enzyme gene analyses were also compared to determine whether the practice of using a single denitrifying bacterial gene could characterize the overall community composition of denitrifying bacteria. We found that nirK was more diverse than both nirS and the nosZ, and the band structure and richness of the three genes were not related to the sam environmental parameters. This suggests that using a single enzyme gene may not suffice to characterize the community composition of denitrifying bacteria in constructed agricultural wetlands.
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| 38. |
- Nilsson, Josefin E., 1994-, et al.
(författare)
-
Mature wetland ecosystems remove nitrogen equally well regardless of initial planting
- 2020
-
Ingår i: Science of the Total Environment. - Amsterdam : Elsevier. - 0048-9697 .- 1879-1026. ; 716
-
Tidskriftsartikel (refereegranskat)abstract
- Restored and constructed semi-natural wetlands are increasingly used in the agricultural landscape to intercept nutrients from surface waters. Vegetated surface-flow wetlands remove more nitrogen (N) than those without vegetation. However, changes in N removal over time as differently vegetated wetlands progress from early successional stages to mature systems are less investigated. We monitored three different types of initial planting over the course of 12 years, with the aim to examine how planting of newly constructed wetlands affects long-term N removal. All our data were collected in an experimental wetland facility in south-western Sweden. The facility consists of 18 identical small (ca. 25 m2) surface-flow wetlands, simulating semi-natural wetlands in an agricultural landscape. Initially, the 18 wetlands were randomly divided into three treatments (vegetation types) with six replicates each and planted with (1) emergent vegetation, (2) submerged vegetation and (3) no vegetation for free development. Vegetation succession afterwards progressed uninhibited in all wetlands. Emergent vegetation wetlands initially removed more N than both submerged vegetation and free development wetlands. We found that N removal in submerged vegetation and free development wetlands increased with ecosystem age, whereas N removal in emergent vegetation wetlands did not. N removal in all three vegetation types converged when the wetlands reached a more mature state, around 8 years after wetland construction. However, although all wetlands contained emergent vegetation in year 8, the proportion of emergent vegetation cover and vegetation composition still differed substantially between wetland types. Our study indicates that it is not the cover of emergent vegetation per se which promotes higher N removal in more mature wetlands, but the maturation process itself; mature wetlands despite differing emergent vegetation coverage achieved equally high N removal. In conclusion, once wetlands reach maturity, beneficial effects of initial planting on N removal disappear. © 2020 The Authors. Published by Elsevier B.V.
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| 39. |
- Nilsson, Josefin E., et al.
(författare)
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Multifunctional wetlands can efficiently remove nitrogen while reducing flood risk
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Exacerbated by climate change, eutrophication and flood risks are pressing global issues of increasing ecological and societal relevance. A key driver of eutrophication is the excess use of nitrogen (N) fertiliser in agricultural landscapes, resulting in N exports from land to water. Flood events can increase N exports and further worsen eutrophication. Created wetlands in agricultural areas are recognised as important nutrient sinks, and the flood attenuating capabilities of urban wetlands and ponds are also well established. However, less studied is the potential to combine these two ecosystem services in agricultural landscapes to achieve multifunctionality. This study examines how dynamic water management for enhanced water storage capacity during flood events affects N removal and greenhouse gas (GHG) emissions in replicated experimental wetlands. We hypothesised that intermittently flooded wetlands would exhibit higher rates of N removal and nitrous oxide (N2O) emissions, while emitting less methane (CH4), compared to permanently flooded wetlands. However, our hypothesis was refuted. In this experiment, shallow wetlands exhibited high N removal and water retention simultaneously, whereas deep and large wetlands removed less N as water retention increased. No differences in the aqueous concentrations of N2O or CH4 were observed between wetlands with high or low water storage capacity, thus indicating similar emissions. Our results highlight the possibility of combining the two ecosystem services flood attenuation and N removal, without increasing GHG emissions, in wetlands of specific designs. This study contributes to the understanding of synergies and trade-offs in wetland multifunctionality.
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| 40. |
- Nilsson, Josefin E., 1994-
(författare)
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Nitrogen Removal in Created Wetlands : Considerations – Challenges – Possibilities
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Created wetlands in agricultural landscapes deliver a multitude of ecosystem services, one of which is the removal of nitrogen (N) from water to reduce eutrophication. Wetland N removal, primarily through denitrification, is influenced by various factors. For instance, macrophytes support denitrifying microorganisms and thus N removal, and the extent of N removal varies both spatially and temporally. The overall aim of this thesis was to provide a broadened understanding of considerations, challenges, and possibilities associated with achieving high N removal in created wetlands. To fulfil this aim, and thereby address knowledge gaps concerning wetland N removal, this thesis evaluates how N removal is affected by wetland placement and design, planting and harvesting of vegetation, installation of floating wetlands, changing climatic conditions, and interactions with other ecosystem services. These assessments were done using a combination of experimental wetland studies, a field study of created wetlands, and a literature review, all presented in the five included papers. The results highlight the rapid achievement of high N removal in wetlands planted with emergent vegetation, but also the diminishing effects of initial planting as wetland ecosystems approach maturity. Further, N removal is promoted in wetlands placed downstream of fertilised arable land to intercept as much runoff as possible, and in wetlands of elongated shape with maximised distance between inlet and outlet. Through such placement and design, created wetlands can maintain efficient N removal in spite of the anticipated increase in summer droughts. Additionally, multiple wetlands can jointly enhance landscape multifunctionality despite trade-offs between ecosystem services in individual wetlands. Even within a wetland, ecosystem services can synergistically interact. Although dependent on design, created wetlands can efficiently remove N and attenuate floods, without elevating greenhouse gas emissions. Moreover, specific wetland properties promote ecosystem services additional to N removal, making it possible to increase N removal by creating wetlands with other primary objectives. Lastly, N removal in heavily overgrown wetlands can be enhanced through macrophyte harvest, and floating wetlands offer further possibilities of improved N removal. In conclusion, with an improved understanding of wetland N removal, future creation and restoration of wetlands in agricultural areas hold the potential to further contribute to mitigating eutrophication and its detrimental consequences.
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| 41. |
- Nilsson, Josefin E., 1994-, et al.
(författare)
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Näringsavskiljning i anlagda våtmarker i Kalmar län
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I den här studien beräknades kväve- och fosforavskiljningen utifrån automatiserad flödesproportionell provtagning i fem anlagda våtmarker i Kalmar län under tre års tid samt i ett anlagt fosfordike i länet under två år (fortsättningsvis benämns alla sex studieobjekt som våtmarker). Syftet med studien var att utvärdera funktionen av våtmarker i Kalmar län för avskiljning av kväve och fosfor. I rapporten presenteras även nya beräkningsmetoder som tagits fram för att hantera de osäkerheter som oundvikligen följer av denna typ av situ-studier. Denna rapport bör kunna bidra till förbättrade mätmetoder och analyser i framtida våtmarksstudier.De våtmarker som ingår i studien är lokaliserade i fem olika kommuner i Kalmar län. Våtmarkerna som studerats är Hanåsa (Högsby kommun), Resmo (Mörbylånga kommun), Påboda (Torsås kommun), Grisbäck (Torsås kommun), Hossmo (Kalmar kommun) och Häckenstad (Västerviks kommun). Urvalet av våtmarker är gjort av Länsstyrelsen med målsättningen att få ett representativt urval av våtmarker i Kalmar län. Våtmarkerna i studien skiljer sig därför från varandra både i utformning och i vilken omgivning de är anlagda. De flesta av våtmarkerna är cirka en halv hektar stora, men den största våtmarkens area är 2,5 hektar och den minsta har en area på endast 220 kvadratmeter. Några av våtmarkerna har mycket hög andel åkermark i tillrinningsområdet, medan andra våtmarker främst har skog i sitt tillrinningsområde.Flödesproportionell provtagning har kontinuerligt genomförts vid in- och utlopp i fem våtmarker från november 2016 till och med december 2019, och i en våtmark från maj 2018 till och med december 2019. I tre av våtmarkerna mättes flöde både vid inlopp och utlopp, och i tre av våtmarkerna mättes flöde endast vid utlopp. Flödesmätning gjordes en gång per minut, och varje vecka hämtades vattenprover från våtmarkerna för att analyseras för bland annat innehåll av näringsämnen. Den data som samlats in har sedan bearbetats, beräknats och korrigerats för att kunna användas i bedömningen av våtmarkernas näringsavskiljning.Flödena i våtmarkerna följde vanligen tydliga säsongsmönster där sommarflöden var låga och flödestoppar skedde under höst, vinter och vår. Resmo, på Öland, hade längre torrperioder än övriga våtmarker i studien. Näringskoncentrationerna vid de olika våtmarkernas inlopp var i genomsnitt under studien mellan 1,7 och 9,9 mg kväve per liter och mellan 64 och 157 µg fosfor per liter. Kvävet var huvudsakligen i form av nitratkväve, och fosforn var i huvudsak partikelbunden fosfor. Både kväve- och fosforavskiljning i våtmarkerna ökade med ökad belastning. Den genomsnittliga årliga kväve- och fosforavskiljningen per hektar vattenyta skiljde sig stort mellan våtmarkerna. Den varierade från negativ avskiljning i den största våtmarken till över 1 000 kg per hektar vattenyta och år för både kväve och fosfor i den minsta våtmarken (tabell 1). Angivet i procent avskildes i genomsnitt upp till 14 % av den årliga kvävebelastningen och upp till 70 % av den årliga fosforbelastningen. Jämfört med tidigare modellerad kväve- och fosforavskiljning för våtmarker i Kalmar län och andra delar av Sverige var avskiljningen i våtmarkerna i denna studie generellt högre.Tabell 1. Genomsnittlig kväve- och fosforavskiljning angivet per hektar vattenyta och år och i procent av den årliga belastningen i de sex våtmarkerna i studien. På grund av mätosäkerheter anges avskiljningen i vissa av våtmarkerna som ett intervall. Kväveavskiljning FosforavskiljningVåtmark kg ha-1 år-1 % kg ha-1 år-1 %Hanåsa -351 -37 -49 -91Resmo 407 3,8 19 31Påboda 845 – 1 013 12 – 14 20 – 28 22 – 29Grisbäck 523 – 899 7,2 – 12 113 – 153 45 – 54Hossmo 346 – 965 2,7 – 7,3 -1,1 – 14 -4,4 – 13Häckenstad 1 471 4,3 1 688 70Resultaten i denna studie visar att våtmarker i Kalmar län kan uppnå hög näringsavskiljning, men att skillnaderna mellan olika våtmarker är stora. Resultaten visar också att hög kväve- och fosforavskiljning kan uppnås i våtmarker med relativt låg andel åkermark i tillrinningsområdet, och att mycket hög fosforavskiljning kan uppnås i små våtmarker även utan en djuphåla. Projektet bidrar till en bättre bild av vilken avskiljning av kväve och fosfor som kan uppnås i anlagda våtmarker i södra Sverige. Resultat från projektet kan tillsammans med tidigare mätningar utgöra en grund för säkrare modellberäkningar av kväve- och fosforavskiljning, vilka kan användas för att på ett enklare sätt undersöka avskiljningen i ett större antal våtmarker eller för att prediktera vad som kan uppnås i planerade våtmarksprogram.
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| 42. |
- Nilsson, Josefin E., 1994-, et al.
(författare)
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Wetlands in a future climate : How will drier summers affect wetland nitrogen removal?
- 2022
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Ingår i: Abstract Book. ; , s. 138-139
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Wetland nitrogen (N) removal is temperature dependent and therefore generally highest during summer in the northern temperate zone. However, climate change scenarios predict more frequent summer droughts in these regions, resulting in lowered N transports during summer to wetlands created for interception of agricultural runoff. This may adversely affect annual wetland N removal, thus reducing the mitigative effects wetlands have on eutrophication. In this study, continuous flow-proportional sampling was performed in six agricultural wetlands located on the east coast, and three on the west coast, of southern Sweden. These two regions represent different climate conditions, where precipitation is lower and summer temperatures are higher on the east coast. Our results showed a pronounced no-flow period during summer in east coast wetlands, but not in west coast wetlands. No-flow periods only decreased N load and removal rate during summer but had no effect on annual N removal. Annual N removal was instead best explained by multiple regression with annual N load and hydraulic efficiency as predictors. This indicates that low wetland N removal during drier summers may be compensated by higher N removal during other seasons. A possible explanation is that annual N removal through denitrification is determined by the amount of organic carbon provided by wetland vegetation, and that organic carbon not utilized during summer, due to lack of nitrate and oxygen under no-flow conditions, will be available for denitrification during other seasons. In conclusion, climate change might not have the anticipated decreasing effect on wetland N removal.
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| 43. |
- Nilsson, Josefin E., 1994-, et al.
(författare)
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Will planting of surface-flow wetlands improve nitrogen removal in the long run?
- 2019
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Ingår i: Book of Abstracts. - Aarhus : Aarhus Universitetsforlag. - 9788797148600 - 9788797148617 ; , s. 340-340
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Initial planting of created wetlands is common practice in order to, for instance, improve nitrogen (N) removal. It has been shown that vegetated surface-flow wetlands remove more N than non-vegetated surface-flow wetlands. However, changes in N removal as differently vegetated wetlands progress from an early successional stage to a mature system are less investigated.In our study, we followed three different wetland types of initial planting over the course of 12 years, with the aim to examine how planting of newly created wetlands affects long-term N removal. All our data were collected in the experimental wetland facility near Halmstad in south-western Sweden. The facility consist of 18 small (ca. 25 m2) surface-flow wetlands, equal in age, shape and size. At the time of creation, the 18 wetlands were randomly divided into three types. One type was then planted with emergent vegetation, one was planted with submerged vegetation and the last type was left unplanted for free development. Succession of vegetation was thereafter allowed to progress uninhibited in all wetlands.Our results confirmed that emergent vegetation wetlands initially removed more N than submerged vegetation and free development wetlands. In addition, our results showed that N removal in submerged vegetation and free development wetlands increased with ecosystem age, whereas N removal in emergent vegetation wetlands did not. N removal in all three wetland vegetation types converged when the wetlands reached a more mature state, around year 9 after wetland creation. However, although all wetlands contained emergent vegetation in year 9, proportion cover of emergent vegetation and vegetation composition still differed substantially between wetland types.We therefore conclude planting of created surface-flow wetlands with emergent vegetation will have a positive effect on N removal, but only during an early successional stage. Our study indicates it is not the emergent vegetation per se which results in higher N removal in more mature wetlands, but the maturation process in itself, since mature wetlands with different emergent vegetation cover achieved similar N removal. Initial planting will not result in higher N removal once the system has reached maturity.
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| 44. |
- Nilsson, Josefin, et al.
(författare)
-
Kväveavskiljning i multifunktionella våtmarker i ett förändrat klimat
- 2024
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Anlagda våtmarker i jordbrukslandskapet är en viktig del i arbetet med att minska övergödningen av vattendrag, sjöar och kustnära hav. Genom att avskilja kväve och fosfor från jordbruksmarkens avrinning bidrar våtmarker till minskade näringstransporter till akvatiska ekosystem. Kväveavskiljning i våtmarker påverkas av en rad olika faktorer. Växtlighet i våtmarker spelar en viktig roll genom att skapa gynnsamma förhållanden för de mikroorganismer som står för den huvudsakliga kväveavskiljningen. Dessutom påverkar våtmarkens placering och utformning hur mycket kväve som kan avskiljas. En våtmark som ska avskilja stor mängd kväve bör placeras där kvävebelastningen är hög, vilket ofta är nedströms intensivt odlad åkermark. Med pågående klimatförändringar blir somrarna allt torrare och risken att intensiva regn orsakar mycket kraftiga vattenflöden ökar. I framtiden kan det bli så att våtmarker mottar den huvudsakliga delen av årets vattenflöde och kväveavrinning under vinterhalvåret när kväveavskiljningen är mindre effektiv på grund av lägre temperaturer. Dessutom blir det värdefullt om våtmarker i högre utsträckning än idag kan utformas för att dämpa kraftiga vattenflöden i samband med intensiva regn. Med ett förändrat klimat behöver vi därför ökad förståelse för hur kraftigare årstidsvariationer i vattenflöden kan komma att påverka kväveavskiljningen i våtmarker, utformning av våtmarker för ökad flödesbuffring kan påverka kväveavskiljningen, hög kväveavskiljning kan uppnås samtidigt som även andra ekosystemtjänster levereras. Genom en fältstudie, en experimentstudie och delar av en litteraturöversikt utröns effekterna av torrare somrar och ökad flödesbuffring på kväveavskiljnigen i anlagda våtmarker, samt de synergi-och avvägningseffekter som kan uppstå mellan kväveavskiljning och andra ekosystemtjänster. I fältstudien jämförde vi kväveavskiljningen i anlagda våtmarker som hade låga sommarflöden med sådana som hade mer jämnt fördelat vattenflöde över året. Effekten av årstidsvariationer i vattenflöde visade sig vara mindre påtaglig än vi hade väntat oss. På årsbasis var det ingen märkbar skillnad i kväveavskiljning mellan de våtmarker där flödet avtog under somrarna och de våtmarker som hade stabilare flöde året om. För att uppnå hög kväveavskiljning var en hög årlig kvävebelastning, våtmarkens form och mycket övervattensväxter i våtmarken viktigare än under vilken årstid våtmarken mottog mest kväve. Detta indikerar att anlagda våtmarker i jordbrukslandskapet kan fortsätta att fungera väl för kväveavskiljning även om klimatförändringar leder till torrare somrar i framtiden. Experimentstudien belyser möjligheten att med bibehållen kväveavskiljning kunna utforma våtmarker för att i högre grad buffra kraftiga vattenflöden genom att de fylls med vatten vid höga flöden och töms vid låga flöden. Experimentstudien visar att en nyckelaspekt för en lyckad kombination av kväveavskiljning och ökad flödesbuffring är att vatten som tillförts våtmarken vid höga flöden hålls kvar i våtmarken tillräckligt länge vid efterföljande lågflödesperiod för att en effektiv kväveavskiljning ska hinna ske. Experimentstudien kunde inte påvisa att växthusgasutsläpp (lustgas och metan) från våtmarker påverkas av att de utformas för flödesbuffring. Innan resultaten av detta experiment implementeras i storskaliga våtmarker behöver effekterna av stora vattenståndsfluktuationer på våtmarkers olika ekosystemtjänster och biologisk mångfald klarläggas ytterligare. Litteraturöversikten visade att det finns utmaningar när våtmarker anläggs med flera syften, alltså ska fungera multifunktionellt. Det finns egenskaper hos våtmarker och omgivande landskap som kan gynna vissa ekosystemtjänster medan andra missgynnas. Exempelvis så ger en våtmarksplacering med hög näringstillförsel (kväve och fosfor) möjligheter till hög näringsavskiljning, samtidigt som det kan ge hög produktion av växthusgaser i våtmarken. Hög näringstillgång är dessutom ofta inte optimalt för biologisk mångfald i en våtmark. För att verkligen uppnå multifunktionalitet krävs våtmarkslandskap, det vill säga landskap där flera typer av våtmarker ingår. Om varje enskild våtmark uppfyller sitt specifika huvudsyfte kan de tillsammans bilda ett multifunktionellt våtmarkslandskap där kväve avskiljs samtidigt som andra ekosystemtjänster levereras. Enskilda våtmarker kan dock också vara multifunktionella. Exempelvis så bidrar våtmarker som anlagts för kväveavskiljning till en ökad biologisk mångfald i jordbrukslandskapet. Detta projekt visar också på möjligheten att flödesbuffrande våtmarker även kan bidra till kväveavskiljning. Sammanfattningsvis så kan, även i ett framtida klimat med förändrade hydrologiska mönster, hög kväveavskiljning uppnås genom välplanerad placering och utformning av anlagda våtmarker i jordbrukslandskapet. Det är även möjligt att utforma våtmarker för ökad flödesbuffring med bibehållen kväveavskiljning. För att flödesbuffrande våtmarker ska kunna dämpa översvämningar i betydande grad, behöver de dock bli väsentligt större än vad anlagda våtmarker vanligtvis är idag. Genom att utöver enskilda våtmarker också fokusera på hela våtmarkslandskap kan leverans av multipla ekosystemtjänster enklare uppnås än om fokus endast ligger på en specifik våtmark. Även om klimatet förändras verkar således våtmarkers och våtmarkslandskaps förmåga att reducera övergödningseffekter och tillhandahålla andra viktiga ekosystemfunktioner kunna bestå.
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| 45. |
- Nilsson, Josefin, et al.
(författare)
-
Wetland nitrogen removal from agricultural runoff in a changing climate
- 2023
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Ingår i: Science of the Total Environment. - Amsterdam : ELSEVIER. - 0048-9697 .- 1879-1026. ; 892
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Tidskriftsartikel (refereegranskat)abstract
- Wetlands in agricultural areas mitigate eutrophication by intercepting nutrient transports from land to sea. The role of wetlands for nutrient removal may become even more important in the future because of the expected increase in agricultural runoff due to climate change. Because denitrification is temperature dependent, wetland nitrogen (N) removal usually peaks during the warm summer. However, climate change scenarios for the northern temperate zone predict decreased summer and increased winter flows. Future wetlands may therefore shift towards lower hydraulic loading rate and N load during summer. We hypothesised that low summer N loads would decrease annual wetland N removal and tested this by examining 1.5-3 years of continuous N removal data from created agricultural wetlands in two regions in southern Sweden (East and West) during different periods. West wetlands showed relatively stable hydraulic loads throughout the year, whereas East wetlands had pronounced no-flow periods during summer. We compared East and West wetlands and tested the effects of several variables (e.g., N concentration, N load, hydraulic load, depth, vegetation cover, hydraulic shape) on annual absolute and relative N removal. We found no difference in annual N removal between East and West wetlands, even though summer N loads were lower in East than in West wetlands. A possible explanation is that stagnant water conditions in East wetlands suppressed decomposition of organic matter during summer, making more organic matter available for denitrification during winter. Absolute N removal in all wetlands was best explained by N load and hydraulic shape, whereas relative N removal was best explained by emergent vegetation cover and hydraulic shape. This study highlights the importance of design and location of agricultural wetlands for high N removal, and we conclude that wetlands in a future climate may remove N from agricultural runoff as efficiently as today.
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| 46. |
- Pedersen, Eja, 1957-, et al.
(författare)
-
Värdering av kulturella ekosystemtjänster baserat på bidrag till livskvalitet
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Begreppet ekosystemtjänster kan bidra till att synliggöra värden i naturen som människor är beroende av för sin överlevnad och sin välfärd. Genom att integrera värdet av ekosystemtjänster i beslutsfattande på kommunal och regional nivå skapas bättre underlag för en helhetsbedömning. Det gäller även kulturella ekosystemtjänster, det vill säga de tjänster som människor får direkt av naturen i form av exempelvis rekreation och estetiska upplevelser.I rapporten undersöks om etablerade teorier, begrepp och metoder från miljöpsykologisk forskning kring interaktionen mellan människa och naturmiljö kan bidra till förståelsen av kulturella ekosystemtjänster och deras värde. Studien visar på ett konkret sätt hur begreppet ekosystemtjänster kan komma till praktisk nytta.Den här rapporten är ett resultat från ett av sju projekt inom forskningssatsningen Värdet av ekosystemtjänster och har författats av forskare vid Lunds Universitet och Högskolan i Halmstad. Projektet finansierades av Naturvårdsverkets miljöforskningsanslag.
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| 47. |
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| 48. |
- Pedersen, Eja, 1957-, et al.
(författare)
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Wetland areas' direct contributions to residents' well-being entitle them to high cultural ecosystem values
- 2019
-
Ingår i: Science of the Total Environment. - Amsterdam : Elsevier. - 0048-9697 .- 1879-1026. ; 646, s. 1315-1326
-
Tidskriftsartikel (refereegranskat)abstract
- Wetlands in urban areas will be crucial to counteract the effects of climate change, for example, by improving flood protection and regulating local climate. To gain acceptance for larger-scale creation of wetlands, total values must be identified and revealed. Provisioning and regulating ecosystem services can be described as the quantitative effect, but cultural ecosystem services require other assessments. This study sought to determine whether peri-urban and urban wetland areas contribute to the well-being and quality of life of nearby residents, and to capture their value relative to two other types of green areas (i.e., parks and urban forests). A postal questionnaire survey, based on validated environmental psychology instruments, was distributed to residents in three municipalities with wetland areas of different structures and locations. In these municipalities, respondents (n = 474; response rate = 40%) reported that the wetland area contributed to several quality-of-life aspects, such as encountering nature and experiencing beauty. The areas also facilitated activities that support well-being, were perceived to have high restorative qualities, and evoked positive affective responses. All wetland areas were rated high on most of the measured concepts, but their value relative to other green areas differed possibly depending on the accessibility of the wetland and the availability of other green areas. The location and extent to which the wetland area was integrated in the residential area determined what quality-of-life aspects were most satisfied. Wetland areas can be ascribed cultural ecosystem service values based on how residents perceive their contribution to their quality of life. These values can be added to those of provisioning and regulating ecosystem services, forming the basis for planning urban environments. © 2018 The Authors
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| 49. |
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| 50. |
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