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dc.contributor.authorOksanen, Lauri Kalervo
dc.date.accessioned2016-03-03T12:54:34Z
dc.date.available2016-03-03T12:54:34Z
dc.date.issued2015-11-09
dc.description.abstractSpatial variation in the strength of trophic cascades in arctic tundra has been related to flows of subsidies across ecosystem boundaries. Here, we ask whether the input of marine subsidies in tundra systems would cause spatial variation in the strength of rodent–plant interactions between coastal areas, where predators have access to marine-derived resources, and non-subsidized inland areas of northern Fennoscandia. We present a detailed evaluation of predator–rodent–vegetation interactions along a coast-inland gradient, during the 2011 rodent outbreak and the two following decline years, by using direct assessments of rodent impacts and tracing of marine-derived nutrients in the food web. Our results revealed that the main rodent predator during summer, the long-tailed jaeger Stercorarius longicaudus, did not benefit from marine resources while breeding (relative dietary proportion in chicks’ diet = 0–3%). Contrary to this pattern, parasitic jaegers S. parasiticus, bred exclusively near the coast and preyed effectively on both marine resources (41% of chicks’ diet) and rodents (12%). Mammalian predators also showed a higher activity during winter near the coast. Despite overall higher predator numbers, no evidence was found for lower rodent population growth rates during the three monitoring summers and for weaker rodent grazing impacts in the coastal area. Instead, we documented pronounced damages caused by lemmings and voles on bryophytes and vascular plants, especially dwarf shrubs (e.g. Vaccinum myrtillus) all along the coast–inland gradient. Taken together, our results did not support the hypothesis that marine subsidies would trigger a trophic cascade in coastal tundra areas of northern Fennoscandia during a major rodent outbreak, probably due to a relatively low diversity of marine-subsidized predators in the region. Comparative observational and experimental studies at large spatial scales in various arctic regions are absolutely necessary for a better understanding of factors causing regional variations in the functioning of arctic food webs.en_US
dc.descriptionAccepted manuscript version. Published version at <a href=http://doi.org/10.1111/ecog.01758>http://doi.org/10.1111/ecog.01758</a>.en_US
dc.identifier.citationEcography 2015, 38:1-13en_US
dc.identifier.issn1600-0587
dc.identifier.otherFRIDAID 1324080
dc.identifier.otherdoi: 10.1111/ecog.01758
dc.identifier.urihttps://hdl.handle.net/10037/8649
dc.identifier.urnURN:NBN:no-uit_munin_8172
dc.language.isoengen_US
dc.publisherWileyen_US
dc.rights.accessRightsopenAccess
dc.subjectexclosureen_US
dc.subjectherbivoreen_US
dc.subjectlemmingen_US
dc.subjectmarine subsidiesen_US
dc.subjectpopulation regulationen_US
dc.subjectpredator-prey interactionsen_US
dc.subjecttrophic cascadeen_US
dc.subjectvoleen_US
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480::Systematisk zoologi: 487en_US
dc.subjectVDP::Mathematics and natural science: 400::Zoology and botany: 480::Systematic zoology: 487en_US
dc.titlePredator–rodent–plant interactions along a coast–inland gradient in Fennoscandian tundraen_US
dc.typeJournal articleen_US
dc.typeTidsskriftartikkelen_US
dc.typePeer revieweden_US


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