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dc.contributor.advisorHämäläinen, Heikki
dc.contributor.advisorErcoli, Fabio
dc.contributor.authorNzobeuh, Polain
dc.date.accessioned2015-05-21T09:11:32Z
dc.date.available2015-05-21T09:11:32Z
dc.date.issued2014
dc.identifier.otheroai:jykdok.linneanet.fi:1474058
dc.identifier.urihttps://jyx.jyu.fi/handle/123456789/45975
dc.description.abstractLong term studies are widely used nowadays in many fields of ecology. For instance, records over years represent a valuable tool to monitor and comprehend environmental changes. In freshwater ecology, long term studies are often applied in restoration effect assessments using a before-after-control-impact design. Little is known about the long term effects of freshwater predators on their prey, for example of how crayfish as omnivorous predators affect macroinvertebrate prey communities. Bottom substrate of stony littoral shores in three sites of Lake Päijänne, in Central Finland, were sampled for macroinvertebrates (MI) during five consecutive years and identified mainly to species. Of the three sites one was without crayfish, a second with a newly-introduced signal crayfish population, and a third one with a well-established signal crayfish population. Annual crayfish catching was also performed at the sites. Crayfish establishment was not yet successful as there was no population development after the introduction. Therefore, MI density and taxa richness showed no clear trend, though there were differences among years after the introduction of the predator. Snail densities and species richness increased one year after the introduction and later decreased significantly. No change was observed at the control site in density and taxa richness of MI and snails over years whereas at the crayfish site, there was a significant increase in total density and taxa richness in the last year. This might result from decreased crayfish abundance in the last two study years. Ordination analysis showed no clear interannual directional change in community composition, but the sites were clearly differentiated. The study showed that the effects of established signal crayfish populations on MI communities are fairly consistent in time, but that crayfish establishment and manifestation of effects on MI may require considerable time in large boreal lake littorals.en
dc.format.extent1 verkkoaineisto (23 sivua)
dc.language.isoeng
dc.rightsThis publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited.en
dc.rightsJulkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty.fi
dc.subject.otherAlien species
dc.subject.otherfreshwater predation
dc.subject.otherlong term studies
dc.subject.otherPacifastacus leniusculus
dc.titleInterannual variation in littoral benthic macroinvertebrate communities under contrasting crayfish predation in a large boreal lake
dc.identifier.urnURN:NBN:fi:jyu-201505211935
dc.type.ontasotPro gradufi
dc.type.ontasotMaster's thesisen
dc.contributor.tiedekuntaMatemaattis-luonnontieteellinen tiedekuntafi
dc.contributor.tiedekuntaFaculty of Sciencesen
dc.contributor.laitosBio- ja ympäristötieteiden laitosfi
dc.contributor.laitosDepartment of Biological and Environmental Scienceen
dc.contributor.yliopistoUniversity of Jyväskyläen
dc.contributor.yliopistoJyväskylän yliopistofi
dc.contributor.oppiaineAkvaattiset tieteetfi
dc.contributor.oppiaineAquatic sciencesen
dc.date.updated2015-05-21T09:11:32Z
dc.rights.accesslevelopenAccessfi
dc.contributor.oppiainekoodi4012
dc.subject.ysovieraslajit
dc.subject.ysomakea vesi
dc.subject.ysosaalistus
dc.subject.ysoravut


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