| 1. |
- Bergstrand, Karl-Johan, et al.
(författare)
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Nulägesanalys trädgård
- 2018
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Rapport (populärvet., debatt m.m.)abstract
- Rapporten Nulägesanalys - trädgård har genomförts inom ramen för projektgruppen Insatsstyrka trädgård. Syftet med inventeringen har varit att ge svar på vem som jobbar med trädgårdsvetenskap, vilka forskargrupper och med vilka forskningsämnen, samt identifiera framtida arbetsfält inom ämnet trädgårdsvetenskap och därmed ge uppslag för framtida utveckling av forskningsfält, utbildning och samverkan. I detta ingår att kartlägga trädgårdsvetenskaplig forskning, utbildning och samverkan vid SLU. Nulägesanalysen förväntas därmed ge en grund för fortsatt strategiskt arbete med att utveckla ämnet trädgårdsvetenskap (Horticultural Science) utifrån inventerade resurser och förutsättningar.
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| 2. |
- Birkhofer, Klaus, et al.
(författare)
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Methods to identify the prey of invertebrate predators in terrestrial field studies
- 2017
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 7:6, s. 1942-1953
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Tidskriftsartikel (refereegranskat)abstract
- Predation is an interaction during which an organism kills and feeds on another organism. Past and current interest in studying predation in terrestrial habitats has yielded a number of methods to assess invertebrate predation events in terrestrial ecosystems. We provide a decision tree to select appropriate methods for individual studies. For each method, we then present a short introduction, key examples for applications, advantages and disadvantages, and an outlook to future refinements. Video and, to a lesser extent, live observations are recommended in studies that address behavioral aspects of predator-prey interactions or focus on per capita predation rates. Cage studies are only appropriate for small predator species, but often suffer from a bias via cage effects. The use of prey baits or analyses of prey remains are cheaper than other methods and have the potential to provide per capita predation estimates. These advantages often come at the cost of low taxonomic specificity. Molecular methods provide reliable estimates at a fine level of taxonomic resolution and are free of observer bias for predator species of any size. However, the current PCR-based methods lack the ability to estimate predation rates for individual predators and are more expensive than other methods. Molecular and stable isotope analyses are best suited to address systems that include a range of predator and prey species. Our review of methods strongly suggests that while in many cases individual methods are sufficient to study specific questions, combinations of methods hold a high potential to provide more holistic insights into predation events. This review presents an overview of methods to researchers that are new to the field or to particular aspects of predation ecology and provides recommendations toward the subset of suitable methods to identify the prey of invertebrate predators in terrestrial field research.
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| 3. |
- Egan, Paul A., et al.
(författare)
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Pollinators and herbivores interactively shape selection on strawberry defence and attraction
- 2021
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Ingår i: Evolution Letters. - : John Wiley & Sons. - 2056-3744. ; 5:6, s. 636-643
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Tripartite interactions between plants, herbivores, and pollinators hold fitness consequences for most angiosperms. However, little is known on how plants evolve in response-and in particular what the net selective outcomes are for traits of shared relevance to pollinators and herbivores. In this study, we manipulated herbivory ("presence" and "absence" treatments) and pollination ("open" and "hand pollination" treatments) in a full factorial common-garden experiment with woodland strawberry (Fragaria vesca L.). This design allowed us to quantify the relative importance and interactive effects of herbivore- and pollinator-mediated selection on nine traits related to plant defence and attraction. Our results showed that pollinators imposed stronger selection than herbivores on traits related to both direct and indirect (i.e., tritrophic) defence. However, conflicting selection was imposed on inflorescence density: a trait that appears to be shared by herbivores and pollinators as a host plant signal. However, in all cases, selection imposed by one agent depended largely on the presence or ecological effect of the other, suggesting that dynamic patterns of selection could be a common outcome of these interactions in natural populations. As a whole, our findings highlight the significance of plant-herbivore-pollinator interactions as potential drivers of evolutionary change, and reveal that pollinators likely play an underappreciated role as selective agents on direct and in direct plant defence.
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| 4. |
- Hambäck, Peter A, et al.
(författare)
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Asymmetric indirect interactions mediated by a shared parasitoid: connecting species traits and local distribution patterns for two chrysomelid beetles
- 2006
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Ingår i: Oecologia. - : Springer Science and Business Media LLC. - 0029-8549 .- 1432-1939. ; 148:3, s. 475-481
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports on an asymmetric indirect interaction between two chrysomelid beetles where one species (Galerucella tenella) experiences higher parasitization, and the other species (Galerucella calmariensis) lower parasitization, in mixed compared with monospecific populations. This pattern is likely to be a consequence of differences in life history characteristics, where the inferior species has a smaller body size, a lower fecundity and supports a lower parasitoid density than the superior species. This connection between life history characteristics and interspecific dominance in host–parasitoid systems corresponds to predictions from current community ecology theory, and provides a useful building-block in the development of a predictive theory of parasitoid effects on host coexistence.
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| 5. |
- Hambäck, Peter A., et al.
(författare)
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Bayesian species delimitation reveals generalist and specialist parasitic wasps on Galerucella beetles (Chrysomelidae) : sorting by herbivore or plant host
- 2013
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Ingår i: BMC Evolutionary Biology. - : BioMed Central. - 1471-2148. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Background: To understand the ecological and evolutionary consequences of species interactions in food webs necessitates that interactions are properly identified. Genetic analyses suggest that many supposedly generalist parasitoid species should rather be defined as multiple species with a more narrow diet, reducing the probability that such species may mediate indirect interactions such as apparent competition among hosts. Recent studies showed that the parasitoid Asecodes lucens mediate apparent competition between two hosts, Galerucella tenella and G. calmariensis, affecting both interaction strengths and evolutionary feedbacks. The same parasitoid was also recorded from other species in the genus Galerucella, suggesting that similar indirect effects may also occur for other species pairs. Methods: To explore the possibility of such interactions, we sequenced mitochondrial and nuclear genetic markers to resolve the phylogeny of both host and parasitoid and to test the number of parasitoid species involved. We thus collected 139 Galerucella larvae from 8 host plant species and sequenced 31 adult beetle and 108 parasitoid individuals. Results: The analysis of the Galerucella data, that also included sequences from previous studies, verified the five species previously documented as reciprocally monophyletic, but the Bayesian species delimitation for A. lucens suggested 3-4 cryptic taxa with a more specialised host use than previously suggested. The gene data analyzed under the multispecies coalescent model allowed us to reconstruct the species tree phylogeny for both host and parasitoid and we found a fully congruent coevolutionary pattern suggesting that parasitoid speciation followed upon host speciation. Conclusion: Using multilocus sequence data in a Bayesian species delimitation analysis we propose that hymenopteran parasitoids of the genus Asecodes that infest Galerucella larvae constitute at least three species with narrow diet breath. The evolution of parasitoid Asecodes and host Galerucella show a fully congruent coevolutionary pattern. This finding strengthens the hypothesis that the parasitoid in host search uses cues of the host rather than more general cues of both host and plant.
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| 6. |
- Jivegård, Lennart, 1950, et al.
(författare)
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Effects of three months of low molecular weight heparin (dalteparin) treatment after bypass surgery for lower limb ischemia--a randomised placebo-controlled double blind multicentre trial.
- 2005
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Ingår i: European journal of vascular and endovascular surgery : the official journal of the European Society for Vascular Surgery. - : Elsevier BV. - 1078-5884. ; 29:2, s. 190-8
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To test the hypothesis that long-term postoperative dalteparin (Fragmin), Pharmacia Corp) treatment improves primary patency of peripheral arterial bypass grafts (PABG) in lower limb ischemia patients on acetylsalicylic acid (ASA) treatment. DESIGN: Prospective randomised double blind multicenter study. MATERIALS AND METHODS: Using a computer algorithm 284 patients with lower limb ischemia, most with pre-operative ischemic ulceration or partial gangrene, from 12 hospitals were randomised, after PABG, to 5000 IU dalteparin or placebo injections once daily for 3 months. All patients received 75 mg of ASA daily for 12 months. Graft patency was assessed at 1, 3 and 12 months. RESULTS: At 1 year, 42 patients had died or were lost to follow-up. Compliance with the injection schedule was 80%. Primary patency rate, in the dalteparin versus the control group, respectively, was 83 versus 80% (n.s.) at 3 months and 59% for both groups at 12 months. Major complication rates and cardiovascular morbidity were not different between the two groups. CONCLUSIONS: In patients on ASA treatment, long-term postoperative dalteparin treatment did not improve patency after peripheral artery bypass grafting. Therefore, low molecular weight heparin treatment cannot be recommended for routine use after bypass surgery for critical lower limb ischemia.
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| 7. |
- Krokene, Paal, et al.
(författare)
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Pest risk categorization – New plant health regulations for Norway : Scientific Opinion of the Panel on Plant Health of the Norwegian Scientific Committee for Food and Environment
- 2021
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Rapport (refereegranskat)abstract
- In an ongoing effort to renew Norwegian regulations related to plants and measures against plant pests, the Norwegian Food Safety Authority asked The Norwegian Scientific Committee for Food and Environment (VKM) which of the currently regulated pests that should still be regulated (either as a quarantine pest (QP) or a regulated non-quarantine pest (RNQP) for Norway), and whether there are any species that should be deregulated. Following such a risk categorization process the Norwegian Food Safety Authority will determine if pest risk assessments (PRA’s) should be performed for quarantine pests. International trade regulations define quarantine pests (QPs) as pests of potential economic importance to an area that are not yet present, or are present but not widely distributed and are subject to official control. A regulated non-quarantine pest (RNQP) is a pest whose presence in plants for planting affects the intended use of those plants with an economically unacceptable impact and which is therefore subject to official control within the territory of the importing contracting party and regulated in international trade. In this report VKM presents an overview of the pest categorisation of some of the pests regulated in the current Norwegian regulation and concludes on whether each pest should be regulated as a potential QP, RNQP or none of these categories for Norway. The pest categorisation process – the process of determining whether a pest has or has not the characteristics of a QP or RNQP – has been done using the FinnPRIO model. The FinnPRIO model is a pest risk ranking tool that uses a hypervolume approach carry out quick, semiquantitative expert assessments and that allows a high number of pest risk categorizations to be done cost-effectively and in a short period of time. In total 33 pests were assessed as per request from the Norwegian Food Safety Authority. Of those 33 pests VKM suggests that the vast majority – 32 pests – are kept as a QPs for Norway. However, one pest, the cherry leafroll nepovirus (EPPO code CLRV00), fulfils the requirements for being a RNQP since it is most likely present in Norway already. Furthermore, one organism, the flatworm Arthurdendyus triangulates (ARDDTR), is suggested to not be regulated as QP or RNQP. This pest does not fulfil the requirements for being a QP since it would probably not cause direct damage to plants if it established in Norway. Also, it does not fulfill the requirements for being a regulated non-quarantine pest(RNQP) since its potential presence in plants for planting does not directly affect the intended use of those plants with an economically unacceptable impact.
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| 8. |
- Muola, Anne, et al.
(författare)
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Direct and Pollinator-Mediated Effects of Herbivory on Strawberry and the Potential for Improved Resistance
- 2017
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Ingår i: Frontiers in Plant Science. - : Frontiers Media S.A.. - 1664-462X. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- The global decline in pollinators has partly been blamed on pesticides, leading some to propose pesticide-free farming as an option to improve pollination. However, herbivores are likely to be more prevalent in pesticide-free environments, requiring knowledge of their effects on pollinators, and alternative crop protection strategies to mitigate any potential pollination reduction. Strawberry leaf beetles (SLB) Galerucella spp. are important strawberry pests in Northern Europe and Russia. Given that SLB attack both leaf and flower tissue, we hypothesized pollinators would discriminate against SLB-damaged strawberry plants (Fragaria vesca, cultivar 'Rugen'), leading to lower pollination success and yield. In addition we screened the most common commercial cultivar 'Rugen' and wild Swedish F. vesca genotypes for SLB resistance to assess the potential for inverse breeding to restore high SLB resistance in cultivated strawberry. Behavioral observations in a controlled experiment revealed that the local pollinator fauna avoided strawberry flowers with SLB-damaged petals. Low pollination, in turn, resulted in smaller more deformed fruits. Furthermore, SLB-damaged flowers produced smaller fruits even when they were hand pollinated, showing herbivore damage also had direct effects on yield, independent of indirect effects on pollination. We found variable resistance in wild woodland strawberry to SLB and more resistant plant genotypes than the cultivar 'Rugen' were identified. Efficient integrated pest management strategies should be employed to mitigate both direct and indirect effects of herbivory for cultivated strawberry, including high intrinsic plant resistance.
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| 9. |
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| 10. |
- Stenberg, Johan A., et al.
(författare)
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Herbivore-induced "rent rise" in the host plant may drive a diet breadth enlargement in the tenant
- 2008
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Ingår i: Ecology. - : Ecological Society of America (ESA). - 0012-9658 .- 1939-9170. ; 89:1, s. 126-133
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Tidskriftsartikel (refereegranskat)abstract
- Inter- and intraspecies variations in host plant traits are presumably involved in many host shifts by insect herbivores, and elucidating the mechanisms involved in such shifts has been a crucial goal in insect-plant research for several decades. Here we propose that herbivore-induced evolutionary increases in host plant resistance may cause oligophagous insect herbivores to shift to other sympatric plants as currently preferred host plants become increasingly unpalatable. We tested this hypothesis in a system based on the perennial herb Filipendula uhnaria (Rosaceae), whose herbivory defense has become gradually stronger due to prolonged selection by Galerucella tenella (Coleoptera: Chrysomelidae) herbivory in a boreal archipelago. We. show that Galerucella gradually increases its use of the alternative host plant Rubus arcticus (Rosaceae) in parallel to gradually increased resistance in Filipendula. Our results imply that, by driving the evolutionary increase in Filipendula resistance, Galerucella is also gradually making the original host species more unpalatable and thereby driving its own host-breadth enlargement. We argue that such self-inflicted "rent rises" may be an important mechanism behind host plant shifts, which in turn are believed to have preceded the speciation of many phytophagous insects.
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