miun.sePublikationer
Ändra sökning
Avgränsa sökresultatet
1 - 10 av 10
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Aronsson, Andreas
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Vedaska från biobränslen: resurs eller avfall?2004Ingår i: Finlands Natur, ISSN 0356-4509, Vol. 63, nr 1, s. 15-17Artikel i tidskrift (Övrigt vetenskapligt)
  • 2.
    Aronsson, Andreas
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Ekelund, Nils
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Biological effects of Wood Ash Application.2004Ingår i: Journal of Environmental Quality, ISSN 0047-2425, E-ISSN 1537-2537, Vol. 33, nr 5, s. 1595-1605Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Swedish National Board of Forestry recommends recycling of wood ash for two main reasons: 1) to avoid depletion of essential soil nutrients, and 2) to reduce the harmful effects of acidification of surface waters. There is no doubt that recycling of wood ash to boreal forests will become a major industry in the near future. Much research is conducted regarding the effects of wood ash application on forest growth. Present studies show that, generally speaking, forest growth can be increased on wood ash-ameliorated peatland rich in nitrogen. On mineral soils, however, no change or even decreased growth has been reported. The effects on ground vegetation are not very clear, as well as the effects on fungi, soil microbes and soil decomposing animals. The discrepancies between different studies are for the most part explained by abiotic factors such as variation in fertility among sites, different degrees of stabilization and wood ash dosage used, and different time scales among different studies. The lack of knowledge in the field of aquatic ecosystems and their response to ash application is an important issue for future research. The few studies conducted have mainly considered changes in water chemistry. The biotoxic effects of ash application can roughly be divided into two categories: primary and secondary. Among the primary effects is toxicity deriving from compounds in the wood ash and cadmium is probably the worst among these. The secondary effects of wood ash are generally due to its alkaline capacity and a release of ions into the soil and soil water, and finally, watercourses and lakes. The present review aims to summarize current knowledge in the topic of wood ash application to boreal forest and aquatic ecosystems, and the different effects derived from these actions. ABBREVIATIONS: WAA, Wood ash application; MT, metric tonnes

  • 3.
    Aronsson, K. Andreas
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Effects of wood ash on freshwater organisms and aquatic forest ecosystems2007Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Wood ash application (WAA) has been recommended mainly for two reasons; i) to avoid depletion of minerals in the soil due to whole tree harvest in the forestry and ii) to mitigate harmful effects of acidification of soil and surface waters. In conclusion, the effects on terrestrial ecosystems and, especially, tree growth, can be attributed to the properties of the ash, the dose applied and the specific site at which the ash is applied. The research conducted on the effects of WAA on limnological ecosystems is very limited, and the major purpose of the present thesis was to gain knowledge of the effects of wood ash to different freshwater organisms, and the more comprehensive, limnological effects of WAA in the first stream in Bispgården, Sweden.

    Effects of wood ash solutions on the unicellular alga Euglena gracilis Klebs, the amphipod Gammarus pulex L., and the moss Fontinalis antipyretica Hedw. were investigated under laboratory conditions. Common in all three species was the decline in performance (growth/velocity/respiration/oxygen evolution) when the concentration of wood ash exceeded 5 g/l and no adjustment of pH was done (alkaline solution). In contrast, different movement parameters (motility, upwards swimming and velocity) in E. gracilis (neutral conditions), and increased growth of F. antipyretica with increased concentrations of wood ash indicated that nutrients in the ash was bioavailable for these organisms. There was no evidence of toxic effects on the organisms from metals or other compounds as a result from exposure to wood ash solutions in the present studies.

    The field study was conducted in a forest area close to Bispgården, about 100 km NW from Sundsvall, Sweden. The catchment area (50 ha) of the stream Fanbergsbäcken was treated with wood ash in September of 2004 (3,000 kg/ha;selfhardened crush-ash). In general, both biological (diatoms) and chemical (pH, alkalinity, and aluminum (Al) measurements) indicators have shown no significant effect on acidification parameters from the addition of wood ash. There was, however, evidence of an increased pH during spring flood, accompanied with a decrease in the frequency of low pH values (<5.6) during spring flood. In addition to this, alkalinity was significantly higher in the period 2005-2006, compared to that of 2003. High concentrations of toxic forms of Al repeatedly occured in the stream Fanbergsbäcken, and the WAA did not affect the frequencies of high concentrations of toxic Al forms (<50 μg/l). Both the moss F. antipyretica and the leaves from Alnus incana displayed increased potassium (K) concentrations, although other nutrients did not increase from WAA. In conclusion, no evidence of WAA being effective in restoring or improving the ecological status of freshwater environments has been established, either in the literature or in the present field study. On the other hand, there were no indications of harmful effects due to WAA, either. However, we still do not know the effects of wood ash on several organisms (predominantly invertebrates) inhabiting small ponds and other, temporary or permanent, freshwater ecosystems. In the context of WAA, these environments and organisms have not attended any attention in the research published to date, and future studies are strongly encouraged.

  • 4.
    Aronsson, K. Andreas
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Ekelund, Nils
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Effects on growth, photosynthesis and pigments of the freshwater moss Fontinalis antipyretica Hedw. after exposure to wood ash solution2006Ingår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 372, nr 1, s. 236-246Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The application of wood ash from biofuel sources to the forest has been suggested as a source of nutrients for trees and for restoration of acidified soils and surface waters. Studies on the effects of wood ash on aquatic organisms and ecosystems are, however, few. This study investigated the effects of wood ash (0.1 - 10 g l-1) on the freshwater moss Fontinalis antipyretica Hedw., which has previously been shown to be a sensitive test organism for assessing environmental pollution. After nine weeks of treatment with wood ash, a significant effect of enhanced stem growth was observed at the higher concentrations (1 � 10 g l-1). The concentration of wood ash was also correlated to the growth of secondary branches. Photosynthesis (oxygen evolution after 4 h of exposure to wood ash) was significantly lower in the alkaline treatments (no pH adjustment) compared to the treatments with neutral wood ash solutions (pH adjusted to 7.5). Furthermore, photosynthesis in the alkaline wood ash treatments was significantly lower compared to the control. The ratio between the optical density value before and after acidification (OD665/665a) was higher for all wood ash concentrations compared to the control. The OD665/665a values ranged from 1.52 to 1.61 and there was a difference, however not significant, between the alkaline and the neutral treatment at 10 g l-1 wood ash. This study clearly demonstrated that wood ash may be beneficial for F. antipyretica at moderate concentrations (0.5 - 5 g l-1), particularly when sudden increase in pH is avoided.

  • 5.
    Aronsson, K. Andreas
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Ekelund, Nils
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Effects on Motile Factors and Cell Growth of Euglena gracilis After Exposure to Wood Ash Solution: Assessment of Toxicity, Nutrient Availability and pH-Dependency2005Ingår i: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 162, nr 1-4, s. 353-368Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Wood ash application (WAA) to the forest has been suggested as a resource of nutrients for trees and for restoration of acidified soils and surface waters. However, studies of the effects of WAA on aquatic systems are few. This study investigated the effects of wood ash (1-25 g L-1) on the unicellular flagellate Euglena gracilis, which has been proved to be a sensitive test organism for assessing environmental change. Long-term (7 days) growth studies and short-term (direct, 24 and 48 h) studies of different motile factors, using the automatic biological test system Ecotox, were conducted. The results show no indication of biotoxic effects due to wood ash (adjusted to neutral) treatments. However, when no adjustments of pH in wood ash solutions were made, inhibitory effects on motile factors and cell growth were observed at higher concentrations of wood ash (10-25 g L-1) due to high pH (> 8). In tests with pH adjusted to neutral, enhanced motility was observed. These results indicate that high concentration of WAA could affect freshwater environments.

  • 6.
    Aronsson, K. Andreas
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap, teknik och matematik.
    Ekelund, Nils
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap, teknik och matematik.
    Limnological effects on a first order stream after Wood Ash Application to a boreal forest catchment in Bispgården, Sweden2008Ingår i: Forest Ecology and Management, ISSN 0378-1127, E-ISSN 1872-7042, Vol. 255, nr 1, s. 245-253Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In Sweden, whole tree harvest is common practice, possibly leading to the depletion of mineral nutrients. Furthermore, the increased use of forestry residues for heat production has caused an increasingly growing amount of by-product consisting of wood ash. Therefore, the Swedish Forest Agency has recommended wood ash application (WAA) to replace the mineral nutrients removed by whole tree harvesting, as well as a means to mitigate the acidification of boreal forests and surface waters. In a multidisciplinary study during 2003-2006 in Bispgarden (Sweden), we have investigated the limnological effects on a first order stream after WAA (conducted in 2004; 3000 kg ha-1) to a 50-ha forested catchment. In general, no significant effects on an annual basis were found for acidification parameters, such as pH, alkalinity and toxic forms of aluminum (Al). There was, however, evidence of an increased pH during the spring flood, accompanied by a simultaneous decrease in the frequency of low pH-values (<5.6). Moreover, alkalinity increased in the years 2005 and 2006 compared to that of 2003, although the increase in 2006 was not statistically different from that in 2005 or 2003. High concentrations of Al repeatedly occurred in the stream, and the WAA did not affect the frequencies of high concentrations of toxic Al forms (>50 μg 1-1). The benthic diatom community did not change as a result of the wood ash treatment and the diatom-based index IPS (Indice de PulluoSensibilité) indicated no nutrient enrichment or organic pollution of the stream water. There were, however, indices of elevated concentrations of potassium (K) in the aquatic moss Fontinalis antipyretica and in leaves from Alder (Alnus incana). We conclude that wood ash treatment of a forested catchment with the dose and form of ash applied in this study did not modify the freshwater ecosystem of a first order stream.

  • 7.
    Aronsson, K. Andreas
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Ekelund, Nils
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Respiration measurements can assess the fitness of Gammarus pulex (L.) after exposure to different contaminants: experiments with wood ash, cadmium and aluminum2005Ingår i: Archiv für Hydrobiologie, ISSN 0003-9136, Vol. 164, nr 4, s. 479-491Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Wood ash application has been suggested as a means to mitigate acidification of surface waters. However little is known about the effects of wood ash to freshwater organisms. A Clark-type oxygen electrode was used to investigate the effects of wood ash, cadmium and aluminum on the respiration of the freshwater amphipod Gammarus pulex (L.). Harmful effects following wood ash addition were primarily found to be explained by elevated pH. At high concentrations (> 1 g/l) of wood ash the respiration of G. pulex decreased when no adjustment of pH was made, a response that was negatively correlated to the elevated pH (r = -0.43). An ion-related response was also detected in the pH-adjusted (pH 7) tests, although it was not statistically significant. Cadmium proved to be sublethal in the range of 0.2-0.4mg/l in a 24-h exposure. Mortality was 100% at 0.5 and 1.0mg Cd/l. No effects were detected after exposure to Al, due to the high pH (pH 7-8) of the solutions and the subsequently low concentrations of labile monomeric Al. We demonstrate that the method described in this paper could be a useful probe for the detection of sublethal concentrations of contaminants in freshwater ecosystems.

  • 8.
    Ekelund, Nils
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Aronsson, Andreas
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Changes in chlorophyll a fluorescence in Euglena gracilis and Chlamydomonas reinhardtii after exposure to wood-ash.2007Ingår i: Environmental and Experimental Botany, ISSN 0098-8472, E-ISSN 1873-7307, Vol. 59, nr 1, s. 92-98Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recycling of wood-ash to boreal forests has been suggested to prevent depletion of essential soil nutrient or reduce the negative effects of acidification of surface waters. This study investigated the effects of different concentrations of wood-ash (5, 10 and 12.5 mg l-1 diluted in cultivating medium) on chlorophyll a fluorescence in Euglena gracilis and Chlamydomonas reinhardtii. The green alga C. reinhardtii was more susceptible to wood-ash solutions than the flagellate E. gracilis. Two different forms of wood-ash solutions were tested. In the first solution no adjustment of pH was made. In the second, the pH was adjusted to 7. Wood-ash forms a very strong alkaline reaction if no adjustment of pH is made. The results show that no negative effect on fluorescence yield, electron transport rate (ETR), photochemical quenching (qP) or non-photochemical quenching (NPQ) was observed in E. gracilis. In contrast, C. reinhardtii displayed strong inhibition at concentrations of 10 and 12.5 mg l-1 with non-adjusted pH. The negative effects of high pH on the photosynthetic capacity in C. reinhardtii could either be related to the destruction of the ∆pH across the thylakoid or other parts in the photosynthetic systems that are negatively affected by changing pH. Elevated pH levels in aquatic ecosystems constitute a major environmental stress factor to the phytoplankton community and may lead to loss of diversity among primary producers. If wood-ash application was to become general practice in or near aquatic ecosystems the ash may need to be treated accordingly to avoid rapid changes in pH.

  • 9.
    Ekelund, Nils
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Aronsson, Andreas
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Flagellaten Euglena gracilis rörelseförmåga kan avslöja graden av giftighet (kadmium) i vatten med hjälp av metoden ECOTOX. (Orientation of the flagellate Euglena gracilis can identify the toxicity (cadmium) of water using the automatic biotest ECOTOX).2004Ingår i: Vatten, ISSN 0042-2886, Vol. 60, nr 2, s. 77-84Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The interest in testing of water and wastewater for toxic compounds has increased in the last few years with rising pollutant levels from industry and with rising sensibility towards environmental problems. In order to get an early warning signal of environmental conditions the use of unicellular organism are recommended since they respond quickly and are easy to handle. An early warning system, called ECOTOX, for monitoring of water quality has been developed by a research group in Germany (Prof. D.-P. Häder). ECOTOX use movement parameters of the flagellate Euglena gracilis as orientation in the gravity field, the motility and the velocity of the cells. These parameters have been found to be sensitive to toxic compounds. In the present study it was shown that cadmium affect gravitaxis, motility, velocity and compactness of the cells negatively in the concentration interval of 10 to 15 mg l-1 after 24 and 48 h. After short time of incubation (minutes) with cadmium there is an inhibition of the different movements parameters starting at the concentration of 25 mg l-1. Like other biomonitoring systems ECOTOX can be used to detect changes in quality of aquatic systems.

  • 10.
    Norström, Sara
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Bylund, Dan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Lundström, Ulla
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Vestin, Jenny
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Aronsson, Andreas
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Influence of dissolved organic carbon (DOC) on the water chemistry in two forested catchments2007Ingår i: Proceedings. International Humic Substances Society.11 th Nordic-Baltic Symposium, Functioning of NOM in Environment, Joensuu, Finland June 10-13, 2007, 2007Konferensbidrag (Refereegranskat)
1 - 10 av 10
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf