Survival strategies of macroinvertebrate species under changing ambient conditions of rivers
Zusammenfassung der Projektergebnisse
Global change is predicted to alter environmental conditions of rivers, where species are adapted to. In running waters, temperatures will rise and extreme flow situations such as winter and autumnal floods or summer low flows will increase in frequency and intensity. Whether species can cope with these changes depends on the ecological plasticity but also on life-cycle characteristics (e.g. resistance stages) and their life-table parameter values (e.g. intrinsic growth rate, colonisation ability). The reestablishment of populations after droughts can be mediated by individual resistance (retreat with the water body, drought resistance, ...) or by re-colonisation from spatial refugia via offspring and/or adults. Appling the simulation approach we studied how the zebra mussel Dreissena polymorpha and the Asian clam Corbicula fluminea may react to changing temperature conditions. The day-degree models developed for both species reproduced phenologies of life-stages and shell growth under temperature conditions as currently observed for the River Rhine. Under increasing mean annual water temperatures spawning started earlier in the year. The currently observed temperature plasticity of Dreissena polymorpha is not high enough to cope in the long run with future temperature conditions as already observed in the River Rhine during the exceptional warm summer in 2003, a shift in its optimal temperature towards higher temperatures is needed. Since Corbicula fluminea is much more susceptible to higher temperatures than Dreissena polymorphe we expect that this strategy is also effective for this species. In the second part of our project we tested the hypothesis that the change from a snowmelt system to a groundwater system will alter macroinvertebrate assemblages by favouring other survival strategies. Preliminary results obtained for species such as amphipods or Corbicula fluminea suggest that the ability to follow the water level is most important for survival under both flow regimes. Drought resistance of life-stages and survival in non-preferred areas (unfavourable areas to which a species might be displaced by water fluctuations) is more important under groundwater conditions than in a snowmelt system. The intrinsic growth rate had neither in the groundwater system nor in the snowmelt system an influence on the population density of tested species. This was at least unexpected for the groundwater system, because higher growth rates enable species to rapidly re-establish populations after disturbances. The investigation of higher growth rates than those already analysed will clarify this result.
Projektbezogene Publikationen (Auswahl)
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2004. Survival strategies of macroinvertebrate species under different flow regimes of rivers (SURVSTRAT). 1. AQUASHIFT Workshop
Griebeler, E.M. and Seitz, A.
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2005. Survival strategies of macroinvertebrate species under different flow regimes of rivers: the zebra mussel (Dreissena polymorpha). 2. AQUASHIFT Workshop
Griebeler, E.M., Hennig, A. and A. Seitz
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2005. Survival strategies under different flow regimes: first results. 2. AQUASHIFT Workshop
Hennig, A., Seitz, A., and Griebeler, E.M.
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2005. The individual-based modelling approach exemplified by a model for the zebra mussel Dreissena polymorpha. AQUASHIFT Modelling meeting, Hamburg
Griebeler, E.M.
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2006. Cluster Running waters: Survival strategies of macroinvertebrate species under changing ambient conditions of rivers. 3. AQUASHIFT Workshop
Griebeler, E.M. and A.Seitz
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2006. Contrasting survival strategies of macroinvertebrate species in the Rivers Rhine and Moselle. 3. AQUASHIFT Workshop
Hennig, A., Griebeler, E.M. and A. Seitz
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2007. Demographic effects of increasing temperatures on the zebra mussel Dreissena polymorpha: a simulation study. Abstracts XI Congress of the European Society of Evolutionary Biology, Uppsala Sweden: 119
Griebeler, E.M. and Seitz, A.
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2007. Demographic effects of increasing temperatures on the zebra mussel Dreissena polymorpha: a simulation study. Verhandlungen der Gesellschaft für Ökologie, Band 37: 578
Griebeler, E.M. and Seitz, A.
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2007. Does change in flow regime of rivers alter the macroinvertebrate assemblages? Abstracts 6th European Conference on Ecological Modelling: 212-213
Hennig, A., Griebeler, E.M. and Seitz, A.
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2007. Does change in flow regime of rivers alter the macroinvertebrate assemblages? Verhandlungen der Gesellschaft für Ökologie, Band 37; 554
Hennig, A., Griebeler, E.M. and Seitz, A.
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2007. Effects of increasing temperatures on population dynamics of the zebra mussel Dreissena polymorpha: implications from an individual-based model. Oecologia 151:530-543
Griebeler, E.M. and Seitz, A.
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2007. Effekte der globalen Temperaturerhöhung auf die Populationsdynamik von Arten am Beispiel der Westlichen Beißschrecke (Platycleis albopunctata) und der Dreikantmuschel (Dreissena polymorphe). University of Bielefeld, Bioinformatics group
Griebeler, E.M.
