| 1. |
- Ahonen-Jonnarth, Ulla, et al.
(författare)
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Organic acids produced by mycorrhizal Pinus sylvestris exposed to elevated aluminium and heavy metals concentrations
- 2000
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Ingår i: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 146:3, s. 557-567
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Tidskriftsartikel (refereegranskat)abstract
- A cultivation method was developed to enable exposure of ectomycorrhizal plants with intact extramatrical mycelium to solutions containing different concentrations of aluminium or heavy metals. Pinus sylvestris seedlings colonized by Suillus variegatus (two isolates), Rhizopogon roseolus or Paxillus involutus (two isolates) were used. Seedlings were transferred to Petri dishes containing glass beads and exposed to elevated concentrations of Al, Cd, Cu, or Ni in two ways: immediately following transfer; and after allowing mycorrhizal seedlings to develop an extraradical mycelium that colonized the interface between the upper surface of the beads and the metal-containing solution. Production of organic acids in mycorrhizal and non-mycorrhizal systems was measured by withdrawing samples from the solution and analyzing by HPLC. In most experiments, levels of oxalic acid were significantly higher in mycorrhizal treatments than in non-mycorrhizal controls. The measured levels of organic acids were variable, but the results obtained suggest that production of oxalic acid is stimulated by exposure to elevated Al in mycorrhizal seedlings colonized by S. variegatus and R. roseolus. Elevated Al concentrations also increased oxalic acid production by non-mycorrhizal seedlings significantly in two of four Al experiments performed, but the measured concentrations were significantly lower than in corresponding mycorrhizal treatments in both cases. Malonic acid was found in the culture solution of non-mycorrhizal had P. involutus-colonized seedlings, but only trace amounts were found in S. variegatus or R. roseolus-infected seedlings. Citric, shikimic, lactic, acetic, propionic, fumaric, formic, iso-butyric and butyric acid were found in variable concentrations. Production of oxalic acid by seedlings ColoniZed by S. variegatus BL or P. involutus was not stimulated by exposure to 0.44 μM Cd or 17 μM Ni. Exposure to 0.157 mM CU in two separate experiments using P. involutus 87.017 and two strains of S. variegatus (BL and 159) appeared to stimulate production of oxalic acid irrespective of mycorrhizal status or species.
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| 2. |
- Ahonen-Jonnarth, Ulla, et al.
(författare)
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Effects of elevated nickel and cadmium concentrations on growth and nutrient uptake of mycorrhizal and non-mycorrhizal Pinus sylvestris seedlings
- 2001
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Ingår i: Plant and Soil. - 0032-079X .- 1573-5036. ; 236, s. 129-138
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Tidskriftsartikel (refereegranskat)abstract
- The effects of Ni and Cd on growth and nutrient uptake of mycorrhizal and non-mycorrhizal Pinus sylvestris L. seedlings were investigated in a pot experiment. Seedlings were either inoculated with Laccaria bicolor (Maire) Orton or left uninoculated before being planted in pots containing a mixture of sandy soil from the B-horizon of a coniferous forest, small stones and pure quartz sand. The pots were supplied with small amounts of a balanced nutrient solution every 24 h using peristaltic pumps. Nickel or Cd were added as chlorides to the nutrient solution at levels of 85 μM Ni (Ni 1), 170 μM Ni (Ni 2), or 8.9 μM Cd. Mycorrhizal colonisation of the roots was nearly 100% in the mycorrhizal treatments. The mycorrhizal seedlings grew significantly better than the non-mycorrhizal ones. The weight of mycorrhizal seedlings in the Ni 2 treatment was 29% lower than that of the mycorrhizal controls, but still 34% greater than that of the non-mycorrhizal seedlings not exposed to metals. There was an overall, statistically significant, negative effect of metals on plant yield. Mycorrhizal plants had lower root:shoot (R:S) ratios than non-mycorrhizal plants and the R:S ratio was increased by metal exposure, particularly in the non-mycorrhizal seedlings. Plant concentrations of Cd or Ni were not affected by mycorrhizal colonisation, but total uptake of Cd and Ni was higher in bigger mycorrhizal seedlings. Nickel decreased P concentration in all seedlings and Cd decreased P concentration in the non-mycorrhizal seedlings. Generally, the mycorrhizal seedlings grew better than non-mycorrhizal ones and had better P, K, Mg and S status. Root growth was not significantly affected by the metal treatments. The reduction in mean shoot growth of non-mycorrhizal plants, relative to the metal-free control, appeared higher than in mycorrhizal plants but was not statistically significant due to high variation in the non-mycorrhizal plants not exposed to metals. The main mycorrhizal effect was thus increased nutrient uptake and growth of the seedlings.
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| 3. |
- Ahonen-Jonnarth, Ulla, et al.
(författare)
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Effects of nickel and copper on growth and mycorrhiza of Scots pine seedlings inoculated with Gremmeniella abietina
- 2004
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Ingår i: Forest Pathology. - : Wiley. - 1437-4781 .- 1439-0329. ; 34:6, s. 337-348
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Tidskriftsartikel (refereegranskat)abstract
- Scots pine (Pinus sylvestris) seedlings were planted in soil originating from two localities with different background levels of nickel and copper. In addition, some of the seedlings were exposed to additional nickel (20.5 mg Ni/l of soil) or copper (63.5 mg Cu/l of soil), or a combination of both Ni and Cu, via soil without direct shoot exposure during their second growing period. The seedlings were either irrigated with spring water (pH 6) or got only natural rain during the whole field experiment. All seedlings were inoculated with conidia of a shoot-pathogen Gremmeniella abietina during their third growing season, and harvested the following spring. Lengths of shoots of different year-classes were used as growth estimates. In roots, the proportion of fungal (assumedly mycorrhizal) biomass was estimated by measuring ergosterol concentration. Guajacol peroxidase activity was measured. Short roots were classified into two groups according to their condition and the composition of the mycorrhizal community was expressed as a proportion of morphotypes in the roots. The seedlings exposed to additional Ni had higher shoot growth than the seedlings in the other treatments. The mean Ni concentration in the roots of seedlings exposed to additional Ni was 79 p.p.m. and in other seedlings 16 p.p.m. Additional Ni also decreased the frequency of clearly senescent short roots and the proportion of the mycorrhizal morphotype with the thinnest mantle. These results indicate that the Ni exposure levels used in this experiment had some positive effects on the seedlings. The relative fungal biomass was about 6% lower (p = 0.0981) in the fine roots of seedlings treated with additional Cu. The mean Cu concentration in the roots of seedlings exposed to additional Cu was 256 p.p.m. and in other seedlings 29 p.p.m. Peroxidase activity, which was used as a general stress indicator in this study, was not affected by any of the treatments. The shoot growth and the relative biomass of fungi in the fine roots were positively correlated in all seedlings, and this correlation was stronger in seedlings exposed to additional Ni that were not irrigated compared with seedlings not exposed to additional Ni that were irrigated. The frequency of asymptomatic infections of G. abietina was positively correlated with the proportion of senescent short roots in the irrigated seedlings but not in not-irrigated seedlings. The general condition of seedlings may be an important factor for infection by G. abietina when moisture is high enough for the fungi to infect seedlings by conidia.
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| 4. |
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| 5. |
- Ahonen-Jonnarth, Ulla, et al.
(författare)
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Growth and nutrient uptake of ectomycorrhizal Pinus sylvestris seedlings treated with elevated Al concentrations and decreased levels of base cations
- 2003
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Ingår i: Tree Physiology. - : Oxford University Press (OUP). - 0829-318X .- 1758-4469. ; 23:3, s. 157-167
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Tidskriftsartikel (refereegranskat)abstract
- Models of the effects of elevated concentrations of aluminum (Al) on growth and nutrient uptake of forest trees frequently ignore the effects of mycorrhizal fungi. In this study, we present novel data indicating that ectomycorrhizal mycelia may prevent leaching of base cations and Al. Mycorrhizal and non-mycorrhizal Pinus sylvestris L. seedlings were grown in sand obtained from the B-horizon of a local forest. In Experiment 1, non-mycorrhizal seedlings and seedlings inoculated with Hebeloma cf. longicaudum (Pers.: Fr.) Kumm. ss. Lange or Laccaria bicolor (Maire) Orton were provided with nutrient solution containing 2.5 mM Al. Aluminum did not affect growth of non-mycorrhizal seedlings or seedlings inoculated with L. bicolor. Seedlings colonized by H. cf. longicaudum had the highest biomass production of all seedlings grown without added Al, but the fungus did not tolerate Al. Shoots of seedlings colonized by L. bicolor had the lowest nitrogen (N) concentrations but the highest phosphorus (P) concentrations of all seedlings. The treatments had small but significant effects on shoot and root Al concentrations. In Experiment 2, inoculation with L. bicolor was factorially combined with the addition of a complete nutrient solution, or a solution lacking the base cations K, Ca and Mg, and solutions containing 0 or 0.74 mM Al. Seedling growth decreased in response to 0.74 mM Al, but the effect was significant only for non-mycorrhizal seedlings. Mycorrhizal seedlings generally had higher P concentrations than non-mycorrhizal seedlings. Aluminum reduced P uptake in non-mycorrhizal plants but had no effect on P uptake in mycorrhizal plants. Mycorrhizal colonization increased the pH of the soil solution by about 0.5 units and addition of Al decreased the pH by the same amount. We conclude that the presence of ectomycorrhizal mycelia decreased leaching of base cations and Al from the soil.
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| 6. |
- Ahonen-Jonnarth, Ulla, et al.
(författare)
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How do people aggregate value? An experiment with relative importance of criteria and relative goodness of alternatives as inputs
- 2022
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Ingår i: Journal of Multi-Criteria Decision Analysis. - : Wiley. - 1057-9214 .- 1099-1360. ; 29:3-4, s. 259-273
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Tidskriftsartikel (refereegranskat)abstract
- The concept of importance of criteria is used as a central element in several decision making contexts, specifically in value aggregation, e.g. as an input to decision support tools. For example, in the analytic hierarchy process (AHP) decision makers are asked to estimate how much more important one criterion is than another. However, it is not clear how people understand aggregation models based on importance of criteria in decision making situations. The purpose of this descriptive study is to investigate if people find an aggregation model in simple value aggregation tasks which remind of the way AHP elicits the input. Further, the purpose is to investigate if people's tendency to find a model depends on their cognitive abilities. In an exploratory laboratory experiment, participants assessed which of two alternatives is the best, based on information about the importance of two criteria and how good the two alternatives are compared to each other with respect to these criteria. The results confirm that people are willing to use importance of criteria and goodness of alternatives as input in value aggregations and show three main models for aggregation. More participants with higher numeracy applied a clear model compared to those with lower numeracy. None of the identified models was one of AHP's models but one of them reminded of one of the ways input can be aggregated in the AHP. The three models identified in the experiment are based on lexicographic order, multiplication and a combination of multiplication and addition. How the results could be used in a prescriptive context is discussed in the paper.
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| 7. |
- Ahonen-Jonnarth, Ulla, et al.
(författare)
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Multi-criteria reasoning models for value aggregation in wind power permit application assessment
- 2023
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Ingår i: Renewable Energy Focus. - : Elsevier. - 1755-0084. ; 45, s. 210-219
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Tidskriftsartikel (refereegranskat)abstract
- Assessment of an application for wind power establishment is a multi-criteria problem including the coreproblem: whether to grant permission or not. In Sweden, County Administrative Boards decide the outcomes of these kinds of applications. Five permit officers were interviewed to investigate the difficultiesand the type of value aggregation in this work, and to test reasoning models as possible decision supporttools. The commonly used type of aggregation was condition-based aggregation. Aggregation based onvalue differences, which means weighing together aspects for and against the wind power establishment,was considered difficult to apply by the respondents. Most of them agreed that some of the aspects thatspeak against granting permission could be aggregated but that aggregation of all aspects would be harddue to differences between aspects. In addition, the value of the main aspect that speaks for permission,climate friendly energy supply, is very difficult to estimate. Thus, aggregation based on value differencesis a difficult question and how it could be performed is discussed in the paper. If policymakers wish tomake it possible to take both positive and negative aspects into consideration and to discuss thetrade-offs transparently, the investigated method can be a way forward.
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| 8. |
- Ahonen-Jonnarth, Ulla, et al.
(författare)
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Simulation as a tool for the evaluation of forest management treatments
- 2010
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Ingår i: ESM'2010 - The 2010 European Simulation and Modelling Conference. - Ghent : EUROSIS-ETI. - 9789077381571 ; , s. 426-433
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Konferensbidrag (refereegranskat)abstract
- Cleaning of young forest stands is a multicriteria problem with conflicting goals. This kind of forest management treatment is performed by human beings but it is possible that this work may be performed by artificial agents in the future. The artificial agents need detailed information about how to clean a forest stand and/or what are the goals for cleaning. One problem in development of cleaning rules for artificial cleaning agents is that explicit knowledge about good cleaning results is not detailed. In this paper we present a tool for developing and testing rules and judging evaluation functions for cleaning. We illustrate this tool by presenting examples of some ways to clean forest stands in a computer environment and we present how the cleaning results can be evaluated. In order to obtain material for experiments it is also possible to simulate forest stands using this tool.
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| 9. |
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| 10. |
- Andersson, Hanna, 1991-, et al.
(författare)
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Anchoring effect in judgments of objective fact and subjective preference
- 2021
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Ingår i: Food Quality and Preference. - : Elsevier. - 0950-3293 .- 1873-6343. ; 88
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Tidskriftsartikel (refereegranskat)abstract
- The way by which various sources of external information interact in their effects on judgment is rarely investigated. Here, we report two experiments that examine how two sources of external information—an anchor (a reference price) and an eco-label—influence judgments of an objective fact (product price) and a subjective preference (willingness-to-pay for the product). Participants’ price judgments were drawn in the direction of the anchor point, whereas the eco-label resulted in higher judgments of objective fact (Experiment 1) but did not influence subjective preference (Experiment 2). Interestingly, the eco-label seemed to strengthen the effect of the high anchor in judgments of objective fact. Further, participants with higher environmental concern answered a higher price on the subjective preference questions when they received a high anchor, as well as a lower price when they received a low anchor in comparison to the low environmental concern group. This study demonstrates that various external information sources can strengthen each other’s effects on consumer belief about products, while the effects are weaker for consumers’ preferences. The implications of the results for decision making are discussed.
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| 11. |
- Andersson, Hanna, 1991-
(författare)
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Tradeoffs between self and environment in environmental judgment and decision making
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- One of the greatest challenges of today is to change our behavior to act more pro-environmentally to reduce global warming. We need to make sacrifices for the environment, e.g., use a means of transportation that take a longer time but causes less CO2 emission. The present thesis aims to study different factors (intrinsic, extrinsic motivational, and extrinsic motivational-neutral information) that influence us when making tradeoffs between self and environment. Paper I examined how an anchor (a reference price) and an ecolabel influence price judgments. It was found that both a judgment of an objective fact (product price) and a subjective preference (willingness to pay for the product) were affected by an anchor. An eco-label resulted in higher judgments of objective facts. People with higher environmental concern were more affected by an anchor when stating their willingness to pay than their low concern counterparts. In Paper II and Paper III, an interaction between a high anchor and a normative message that put the emissions into context was found when making a tradeoff between CO2 emissions and travel time for a flight (Paper II) or a car journey (Paper III). People with higher concern for the environment gave a longer travel time when they received a high anchor (Paper II and Paper III) or no anchor (Paper III). Paper IV investigated how a survey measuring environmental concern can be divided to different indices and how they predict answers in a tradeoff task. The result suggests that a two-factor structure divided into ecocentric and anthropocentric concern is a possible alternative and that people scoring higher on any of the environmental concern indices were willing to travel for a longer time. Taken together, the results show that normative messages, anchors, and concern for the environment are factors that can influence and interact when people make tradeoffs between self and environment in environmental judgment and decision making.
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| 12. |
- Andersson, Hanna, 1991-, et al.
(författare)
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What Influences People’s Tradeoff Decisions Between CO2 Emissions and Travel Time? An Experiment With Anchors and Normative Messages
- 2021
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Ingår i: Frontiers in Psychology. - : Frontiers Media S.A.. - 1664-1078. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- One of the today’s greatest challenges is to adjust our behavior so that we can avoid a major climate disaster. To do so, we must make sacrifices for the sake of the environment. The study reported here investigates how anchors (extrinsic motivational-free information) and normative messages (extrinsic motivational information) influence people’s tradeoffs between travel time and carbon dioxide (CO2) emissions in the context of car travel and whether any interactions with environmental concern (an intrinsic motivational factor) can be observed. In this study, people received either a CO2, health or no normative message together with either a high anchor, a low anchor, or no anchor. People that received both a high anchor and a CO2 emission normative message were willing to travel for a longer time than those that only received a high anchor. If a low anchor was presented, no differences in willingness to travel for a longer time were found between the three different conditions of normative message groups, i.e., CO2 normative message, health normative message, or no normative message. People with higher concern for the environment were found to be willing to travel for a longer time than those with lower concern for the environment. Further, this effect was strongest when a high anchor was presented. These results suggest that anchors and normative messages are among the many factors that can influence people’s tradeoffs between CO2 emission and travel time, and that various factors may have to be combined to increase their influence over pro-environmental behavior and decisions.
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| 13. |
- Blaudez, D., et al.
(författare)
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Differential responses of ectomycorrhizal fungi to heavy metals in vitro
- 2000
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Ingår i: Mycological Research. - : Elsevier. - 0953-7562 .- 1469-8102. ; 104:11, s. 1366-1371
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Tidskriftsartikel (refereegranskat)abstract
- Thirty-nine ectomycorrhizal isolates of Paxillus involutus, Pisolithus tinctorius, Suillus bovinus, S. luteus and S. variegatus were tested on cadmium, copper, nickel and zinc amended media to determine their in vitro tolerance, measured as inhibition of biomass production. Twenty-one isolates were from heavy metal polluted sites, whereas the others were from non-contaminated soils. There was a strong interspecific variation in metal tolerance. S. luteus, S. variegatus and P. tinctorius were more tolerant of Cu, Cd and Zn when compared with P. involutus, whereas the reverse was true for Ni. A high intraspecific heterogeneity in metal tolerance was also found. EC50 values for isolates originating from polluted sites were not statistically different from EC50 values for isolates originating from non-contaminated sites. The findings are discussed in relation to the potential benefits of ectomycorrhizal fungi in protecting their host plants from metal contamination.
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| 14. |
- Bökman, Fredrik, et al.
(författare)
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The psychology of balancing gains and losses for self and the environment : Evidence from a carbon emission versus travel time tradeoff task
- 2021
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Ingår i: Journal of Environmental Psychology. - : Elsevier. - 0272-4944 .- 1522-9610. ; 74
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Tidskriftsartikel (refereegranskat)abstract
- If human behavior is to become more sustainable, people will have to be willing to sacrifice personal gains and benefits for the sake of sustainability. Decisions will have to involve making tradeoffs between what is good for the self and what is good for sustainability. In the present paper, we studied the psychology of such tradeoffs in the context of a carbon dioxide (CO2) emission versus travel time tradeoff task. The experiment investigated how intrinsic motivational factors (environmental concern), extrinsic motivational information (a normative message) and extrinsic motivation-neutral information (anchors) influence these tradeoffs. The results revealed that extrinsic factors interact in their effects on tradeoffs such that participants were willing to travel for a longer time for the benefit of less CO2 emissions when they were externally motivated by a normative message, but only when this motivational emphasis was combined with a high anchor. Furthermore, this interaction was particularly strong in participants with high environmental concern. We conclude that extrinsic and intrinsic motivational factors interact in their effect on making people willing to accept personal losses in exchange for sustainability gains and that these motivational factors may have to be combined with further extrinsic information to influence decisions.
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| 15. |
- Julin Nyquist, Kristina, et al.
(författare)
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Strategic, fundamental and means objectives of different stakeholders in collaboration between universities and surrounding society
- 2022
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Ingår i: Perspectives: Policy and Practice in Higher Education. - : Taylor & Francis. - 1360-3108 .- 1460-7018. ; 26:1, s. 19-27
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Tidskriftsartikel (refereegranskat)abstract
- Universities play an important role in the development of society. However, it is not always clear what the objectives of collaboration between a Higher Education Institution (HEI) and external stakeholders from the surrounding society are. In this study, value-focused thinking was applied to construct structures of strategic, fundamental and means objectives of different stakeholders working practically with collaboration between an HEI and the surrounding society. Respondents in three groups of stakeholders from a university and external parties were interviewed. Focus in this study is on general objectives of collaboration between an HEI and the surrounding society. Based on the interviews and feedback, objectives were identified and SSFMO (Structure of Strategic, Fundamental and Means Objectives) was constructed from each respondent’s answer. Generally, the fundamental objectives differed more between the stakeholders than the means objectives did. How SSFMOs could be used in practical collaboration projects is discussed in the paper.
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| 16. |
- Kuikka, K, et al.
(författare)
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Severe defoliation of Scots pine reduces reproductive investment by ectomycorrhizal symbionts
- 2003
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Ingår i: Ecology. - : Wiley. - 0012-9658 .- 1939-9170. ; 84:8, s. 2051-2061
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Tidskriftsartikel (refereegranskat)abstract
- Reduction in the photosynthetic capacity of plants is presumed to negatively affect their fungal symbionts. To test this hypothesis under natural conditions, we artificially removed 100% of previous year needles in two successive years on Scots pine trees (Pinus sylvestris L.) to simulate pine sawfly attack. Despite a decline in the shoot growth of defoliated trees, root biomass did not differ from control trees. The ergosterol (fungal biomass) and starch concentration of fine roots, however, slightly declined in defoliated trees. Percent ectomycorrhizal colonization of fine root tips remained high in both defoliated and control trees. The dominant tubercle morphotypes were slightly more abundant in the control than in defoliated trees. In contrast to the relatively weak effects on vegetative ectomycorrhizae, reproduction declined near the defoliated pines. Average sporocarp numbers and, consequently, the relative fungal investment to reproduction of the estimated total fungal biomass were more than three times higher near controls than defoliated trees in the first treatment year. Defoliation also reduced the diversity of ectomycorrhizal species producing sporocarps. Mutualistic fungal symbionts may thus alter their reproductive investment in response to restrictions on host resources. Because fungal biomass in the roots as well as colonization percentage remained unchanged, Scots pine evidently continues to invest in the maintenance of the symbiosis despite the reduced photosynthetic capacity due to defoliation.
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| 17. |
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| 18. |
- Markkola, A.M., et al.
(författare)
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Estimates of fungal biomass in Scots pine stands on an urban pollution gradient
- 1995
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Ingår i: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 131:1, s. 139-147
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Tidskriftsartikel (refereegranskat)abstract
- Biomasses of ectomycorrhizal and saprotrophic fungal communities partitioned into sporophores and non‐reproductive structures were estimated in mature Scots pine (Pinus sylvestris L.) stands along an urban nitrogen and sulphur pollution gradient in northern Finland. The average total biomass of fungi varied in the four pollution zones from 14.6 to 20.2 g d. Wt kg−1 soil d. wt and from 73.3 to 108.0 g d. Wt m−2, the mycelia of both mycorrhizai and saprotrophic fungi in the soil comprising 72–80% of the total. The annual carbon allocation to the fungal communities was calculated to vary between 9 and 26% of the estimated annual carbon assimilation at the Scots pine sites. The size of the mean fungal biomass fractions decreased in the following sequence: mycelia in the soil > fungal biomass in fine roots estimated in terms of chitin > sclerotia > fungal biomass in fine roots estimated in terms of ergosterol > sporopbores of mycorrhizal fungi > sporophores of saprotrophie fungi. A positive correlation was obtained between the number of Scots pine mycorrhiza and the average sporophore yield of mvcorrhiaal fungi for three successive years. Tbe sporophore biomass of the mycorrhizal fungi was smaller at the most polluted than at the least polluted sites. The total fungal biomass allocation was not affected by urban pollution.
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| 19. |
- Markkola, A M, et al.
(författare)
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Scots pine responses to CO2 enrichment--I. Ectomycorrhizal fungi and soil fauna.
- 1996
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Ingår i: Environmental Pollution. - : Elsevier. - 0269-7491 .- 1873-6424. ; 94:3, s. 309-16
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Tidskriftsartikel (refereegranskat)abstract
- Ectomycorrhizal Scots pine seedlings were grown in unfertilized forest soil at ambient and double (ca 700 ppm) atmospheric concentrations of CO2. The biomass of seedlings and fungal biomass both in the roots and in the soil and the numbers of certain groups of soil animals were measured under summer conditions and after an artificial winter acclimation period. No biomass parameter showed any significant change due to CO2 elevation. Increases were found during the winter acclimation period in total and fine root biomasses, fungal biomass in the soil and total fungal biomass both in the roots and in the soil, while the ratio of needle biomass: fungal biomass and the shoot: root ratio decreased. The N concentration in previous-year needles was lower in the double CO2 environment than with ambient CO2. Enchytraeids almost disappeared in the double CO2 environment during winter acclimation, while the numbers of nematodes increased at the same time in both treatments.
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| 20. |
- Markkola, A. M, et al.
(författare)
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Shift in ectomycorrhizal community composition in Scots pine (Pinus sylvestris L.) seedling roots as a response to nickel deposition and removal of lichen cover
- 2002
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Ingår i: Environmental Pollution. - : Elsevier. - 0269-7491 .- 1873-6424. ; 120:3, s. 797-803
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Tidskriftsartikel (refereegranskat)abstract
- Scots pine seedlings were exposed to wet-deposited nickel (Ni) and removal of lichen cover in a dry heath Scots pine forest. Ni deposition affected the colonization of roots by indigenous ectomycorrhizal fungi in contrasting ways in intact and skimmed quadrats. Highest frequencies of tubercle morphotypes of ectomycorrhiza were found in quadrats exposed to 100 mg m-2 year-1 Ni in lichen covered treatment, while in skimmed quadrats these peaked after the treatment with 10 mg Ni m-2 year-1. Removal of the lichen layer increased the value of diversity index (H′) of ectomycorrhizal fungal community, probably due to the increase in the evenness of the morphotype distribution. Lichen removal seemed also to improve the condition of the short roots, as the frequencies of poor and senescent short roots were decreased by the removal.
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| 21. |
- Markkola, A. M, et al.
(författare)
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Urban polluted forest soils induce elevated root peroxidase activity in Scots pine (Pinus sylvestris L.) seedlings
- 2002
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Ingår i: Environmental Pollution. - 0269-7491 .- 1873-6424. ; 116:2, s. 273-278
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Tidskriftsartikel (refereegranskat)abstract
- Plant biomass, mycorrhizal status and root peroxidase activity were measured in ectomycorrhizal Scots pine (Pinus sylvestris L.) seedlings grown in urban polluted and native, non-polluted forest soils with added ammonium or potassium sulphates simulating N and S deposition of urban areas. Peroxidase activity in the fine roots of seedlings planted in polluted forest soils was higher than in those planted in non-polluted soils and correlated positively with the activities measured in an earlier study in the roots of mature Scots pines growing at the sites from where the soils were collected. Growth of seedlings and mycorrhizal status were not affected by the origin of soil. Exposing the seedlings to winter acclimation conditions for 6 weeks elevated peroxidase activity in the roots. The addition of ammonium or potassium sulphate to non-polluted soils did not induce elevated root peroxidase activity, although at the levels of 0.5 and 1.0 g of ammonium sulphate a slight increasing trend was observed. We suggest, that indirect biotic factors, i.e. changes in the community structure of soil fungi, early stages of recognition, and defence reactions of pine roots against saprophytic and pathogenic fungi may be participating in the elicitation of peroxidase (POD) activity, although the possible role of heavy metals cannot be excluded.
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| 22. |
- Milutinovic, Goran
(författare)
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Computational and Visual Tools for Geospatial Multi-Criteria Decision-Making
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Geospatial multi-criteria decision-making usually concerns quasi-continuous choice models, with the number of alternatives constrained only by the limits of the used representation model. This sets high demands on the decision-making methods used in the context. The most commonly used approach in geospatial decision-making is combining a method for assigning criteria weights with an aggregation method. As pairwise comparison of alternatives is not feasible when the number of alternatives is large, the weights are usually assigned to criteria without considering the values or the value ranges of the alternatives, an approach often criticized in the decision analysis literature. Apart from criteria weighting controversy, this approach does not allow for advanced use of interactive visualization in the choice phase of the decision-making process. In this thesis, two alternative methods for geospatial decision-making based on the even swaps method are developed. The first method relies on automation of swaps, which makes this method viable for decision problems with any number of alternatives. The second method emanates from the findings of behavioral decision theory, and combines even swaps with reduction of large data sets through quasi-satisficing, allowing for efficient use of interactive visualization in the choice phase of the decision process. Visualization frameworks for both methods are also developed in the thesis. They include both geo-specific representations, such as interactive maps, and infovis techniques such as graphs, diagrams, scatterplots and parallel coordinates. Two studies concerning the impact of interactive visualization on decision-making are presented in the thesis: a study concerning the impact of interactive visualization on geospatial decision-making, and a study concerning potential effects of visual saliency on decision-making. The results of the first study indicated positive effects of interactive visualization on coherency and consistency in performing trade-offs. The results of the second study show that visual saliency may help decision-makers make better decisions. The work presented in this thesis contributes to method development and the use of interactive visualization in the context of geospatial decision-making.
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| 23. |
- Milutinovic, Goran, et al.
(författare)
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Does visual saliency affect decision-making?
- 2021
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Ingår i: Journal of Visualization. - : Springer Nature. - 1343-8875 .- 1875-8975. ; 24:6, s. 1267-1285
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, we explore potential effects of visual saliency on decision quality in context of multi-criteria decision-making (MCDM). We compare two visualization techniques: parallel coordinates (PC) and scatterplot matrices (SPM). We investigate the impact of saliency facilitated by means of either color or size. The saliency and visualization techniques were factors in our analysis, and effects were evaluated in terms of decision quality, attention, time on task, and confidence. Results show that the quality of choice and attention were comparable for all saliency conditions when SPM was used. For PC, we found a positive effect of color saliency both on the quality of choice and on attention. Different forms of saliency led to varying times on task in both PC and SPM; however, those variations were not significant. A comparison of PC and SPM shows, users spent less time on the task, obtained better decision quality, and were more confident with their decision when using PC. To summarize, our findings suggest that saliency can increase attention and decision quality in MCDM for certain visualization techniques and forms of saliency. Another contribution of this work is the novel suggestion of the method to elicit of users’ preferences; its potential benefits are discussed in the end of the paper.
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| 24. |
- Milutinovic, Goran, et al.
(författare)
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Geospatial Decision-Making Framework Based on the Concept of Satisficing
- 2021
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Ingår i: ISPRS International Journal of Geo-Information. - : MDPI. - 2220-9964. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- Decision-making methods used in geospatial decision making are computationally complex prescriptive methods, the details of which are rarely transparent to the decision maker. However, having a deep understanding of the details and mechanisms of the applied method is a prerequisite for the efficient use thereof. In this paper, we present a novel decision-making framework that emanates from the need for intuitive and easy-to-use decision support systems for geospatial multi-criteria decision making. The framework consists of two parts: the decision-making model Even Swaps on Reduced Data Sets (ESRDS), and the interactive visualization framework. The decision-making model is based on the concept of satisficing, and as such, it is intuitive and easy to understand and apply. It integrates even swaps, a prescriptive decision-making method, with the findings of behavioural decision-making theories. Providing visual feedback and interaction opportunities throughout the decision-making process, the interactive visualization part of the framework helps the decision maker gain better insight into the decision space and attribute dependencies. Furthermore, it provides the means to analyse and compare the outcomes of different scenarios and decision paths.
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| 25. |
- Milutinovic, Goran, et al.
(författare)
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GISwaps: A New Method for Decision Making in Continuous Choice Models Based on Even Swaps
- 2018
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Ingår i: International Journal of Decision Support System Technology. - : IGI Global. - 1941-6296 .- 1941-630X. ; 10:3, s. 57-78
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Tidskriftsartikel (refereegranskat)abstract
- This article describes how continuous GIS-MCDM problems are commonly managed by combining some weighting method based on pairwise comparisons of criteria with an aggregation method. The reliability of this approach may be questioned, though. First, assigning weights to criteria, without taking into consideration the actual consequences or values of the alternatives, is in itself controversial. Second, the value functions obtained by this approach are in most cases linear, which is seldom the case in reality. The authors present a new method for GIS-MCDM in continuous choice models based on Even Swaps. The method is intuitive and easy to use, based on value trade-offs, and thus not relying on criteria weighting. Value functions obtained when using the method may be linear or non-linear, and thereby are more sensitive to the characteristics of the decision space. The performed case study showed promising results regarding the reliability of the method in GIS-MCDM context.
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| 26. |
- Milutinovic, Goran, et al.
(författare)
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The impact of interactive visualization on trade-off-based geospatial decision-making
- 2019
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Ingår i: International Journal of Geographical Information Science. - : Taylor & Francis. - 1365-8816 .- 1365-8824 .- 1362-3087. ; 33:10, s. 2094-2123
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Tidskriftsartikel (refereegranskat)abstract
- In a previous work we developed GISwaps, a novel method for geospatial decision-making based on Even Swaps. In this paper, we present the results of an evaluation of a visualization framework integrated with this method, implemented within a decision support system. This evaluation is based on two different studies. In the quantitative study, 15 student participants used GISwaps with no visual features, and 15 participants used GISwaps with the integrated visual framework, as the tool in a solar farm site location case study. The results of the quantitative evaluation show positive impact of the visualization in terms of increased coherency in trade-offs. The results also show a statistically significant difference in average trade-off values between the groups, with users from the non-visual group setting on average 20% higher trade-off values compared with the users in the visual group. In the qualitative study, we had one expert in GIS, two experts in decision-making and two experts in solar energy as a focus user group. Data in this study were obtained by observations and semi-structured interviews with the participants. The impact of the visualization framework was assessed positively by all participants in the expert group.
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| 27. |
- Roitto, M., et al.
(författare)
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Apoplastic and total peroxidase activities in Scots pine needles at subarctic polluted sites
- 1999
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Ingår i: European journal of forest pathology. - : Blackwell. - 0300-1237. ; 29, s. 399-410
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Tidskriftsartikel (refereegranskat)abstract
- A gradient survey was carried out in order to compare peroxidase activity in Scots pine (Pinus sylvestris) needles in relation to distance from the industrial centre of Monchegorsk, on the Kola Peninsula in north-western Russia. Apoplastic and total peroxidase activity and sulphur (S), nickel (Ni) and copper (Cu) content in the needles of mature trees were measured on seven plots located between 10 and 110 km from the pollution source. Peroxidase activities in both current- and previous-year needles increased towards the smelters and showed a positive correlation with needle S, Cu and Ni concentrations. Total peroxidase activities showed a more obvious relationship to the pollution gradient in winter than in autumn. The element contents in the current year needles averaged 1649 ppm (S), 128 ppm (Ni) and 118 ppm (Cu) close to the smelters, 1212 ppm (S), 37 ppm (Ni) and 67 ppm (Cu) at adistance of 40 km and 831 ppm (S), 7 ppm (Ni) and 1 ppm (Cu) at the most distant sampling plot. This study showed that both the apoplastic and total peroxidase activities responded to heavy metal and sulphur pollution up to 40 km from the smelters in winter, which indicated an increased oxidative stress in this area. The harsh climate conditions and the high pollution levels may have had additive effects. However, as peroxidases are considered a general indicator of stress, it is not possible to evaluate the extent to which single pollutants contribute to this enzyme activity.
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| 28. |
- Roitto, M., et al.
(författare)
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Does the lichen mat alleviate the effects of wet deposited nickel on soil microorganisms and Scots pine (Pinus sylvestris L.) seedlings?
- 2001
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Ingår i: Plant and Soil. - : Kluwer Academic Publishers. - 0032-079X .- 1573-5036. ; 230:2, s. 267-277
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Tidskriftsartikel (refereegranskat)abstract
- A field experiment was conducted in a dry heath forest dominated by Scots pine (Pinus sylvestris L.) and a mat-forming lichen (Cladina stellaris (Opiz) Brodo) to assess the effect of wet-deposited nickel (Ni) on pine seedlings and soil microorganisms, and to explore whether an intact lichen mat could act as a buffer against heavy metal deposits. Pine seedlings were planted in quadrats covered by a natural lichen layer and in quadrats from which the lichen layer had been completely removed. The quadrats were exposed to four levels of Ni deposition: 0 (i.e., distilled water), 10, 100 and 1000 mg m-2 year-1 in two growing seasons. Increasing Ni deposition led to an increase in the Ni content of the needles, roots and the soil organic layer. The lichen mat reduced Ni flow to the organic soil layer, but had no significant, reducing effect on needle or root Ni concentration. The most severe Ni treatment had detrimental effects on seedling growth and increased peroxidase activity in the previous years needles. Removal of the lichen layer did not increase susceptibility of seedlings to Ni. Values of maximal carbon use efficiency (Max) and metabolic quotient (qCO2) of the soil microorganisms indicated protective value of the lichen mat to soil microorganisms at the highest Ni treatment. Skimming per se decreased basal respiration, qCO2 and concentrations of potassium in the soil and also increased the lag period of the microorganisms as a response to in situ substrate addition.
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| 29. |
- Saikkonen, Kari, et al.
(författare)
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Defoliation and mycorrhizal symbiosis: a functional balance between carbon sources and below-ground sinks
- 1999
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 2:1, s. 19-26
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Tidskriftsartikel (refereegranskat)abstract
- Herbivory is generally assumed to negatively influence mycorrhizal fungi because of reduced photosynthate to support mycorrhizae following defoliation. We examined effects of 60% and 100% defoliation (excluding current year needles) on tree growth and ectomycorrhizal associations of 10±15 year old Scots pines (Pinus sylvestris). Over 98% of short roots were colonized by mycorrhizal fungi, and contrary to expectation, defoliation did not decrease the proportion of living fungi in fine roots. Furthermore, defoliation did not alter the ratios of produced needle biomass to the biomass of fine roots or living fungi in fine roots. The composition of mycorrhizal morphotypes was changed, however, which suggests competition among different mycorrhizal growth forms owing to their carbon demands. We propose that these outcomes are a consequence of a functional balance between carbon sources in plant foliage and below-ground sinks, i.e. growing roots and mycorrhizal associates.
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| 30. |
- Tarvainen, O, et al.
(författare)
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Changes in Ectomycorrhizal Colonization and Root Peroxidase Activity in Pinus sylvestris Nursery Seedlings Planted in Forest Humus
- 2004
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Ingår i: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 19:5, s. 400-408
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Tidskriftsartikel (refereegranskat)abstract
- Plant biomass, root colonization by ectomycorrhizal (ECM) fungi and root peroxidase (POD) activity were monitored in Scots pine (Pinus sylvestris L.) nursery seedlings during the first growing season after planting (after 4, 8 and 16 weeks, in July, August and October, respectively) in forest humus in outdoor open-top chambers with gaseous atmospheric pollutants (combinations of low levels of ozone, sulfur dioxide and nitrogen oxides). The number of ECM morphotypes as well as root biomass increased towards the end of the growing season, while root POD activity decreased. Fungal biomass estimated as ergosterol concentration peaked in August, 8 weeks after planting. The seedling growth, mycorrhizal status and POD activity in the roots were not affected by the gaseous pollutants.
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