000K utf8 1100 $c2019 1500 eng 2050 urn:nbn:de:gbv:8-diss-254923 3000 van der Heijden, Luuk 4000 Determination of the food sources and of the role of meiofauna in soft-bottom intertidal habitats of the Marennes-Oléron Bay, France, and the Sylt-Rømø Bight, Germany. Importance of themicrophytobenthos-meiofauna pathway, highlighted by community structure, trophic markers and linear inverse food web models.$hChristian-Albrechts-Universität zu Kiel [van der Heijden, Luuk] 4000 Rolle der Meiofauna und ihre Nahrungsquellen in intertidalen Habitaten der Marennes-Oléron Bucht, Frankreich, und der Sylt-Rømø Bucht, Deutschland.Bedeutung der Mikrophytobenthos-Meiofauna-Nahrungskette, dargestellt am Beispiel der Gemeinschaftsstruktur, der trophischen Marker und linearer inverser Nahrungsnetzmodelle.$hChristian-Albrechts-Universität zu Kiel [van der Heijden, Luuk] 4030 Kiel$nChristian-Albrechts-Universität zu Kiel 4209 Meiofauna play an important role in ecosystem processes in soft-bottom benthic habitats, e.g. food web dynamics, related to their high production, their intermediate trophic position and the energy they transfer towards higher trophic levels. The trophic linkages and flows of organic matter related to the meiofauna remain poorly known or taken into account. To better assess the role of meiofauna, the community structure and trophic relationships between food sources and meiofauna were determined in five intertidal soft-bottom habitats (i.e., mudflat, seagrass bed, sandflat) of the Marennes-Oléron Bay, France, and the Sylt-Rømø Bight, Germany, taking temporal variations into account. Meiofauna communities were dominated by nematodes and benthic copepods. Biomass of microphytobenthos and of sediment organic matter were two of the major drivers of community structure. The combination of trophic markers (i.e., stable isotopes, fatty acids) demonstrated that microphytobenthos and bacteria were the major food sources of meiofauna in the five habitats. Information from community structure assessments and trophic marker analyses were implemented in food web models. In all habitats, these models demonstrated that the main flow of carbon to meiofauna originated from microphytobenthos, highlighting negligible changes in meiofauna feeding behavior besides the large differences in availability and productivity of food sources between these habitats. All trophic groups of nematodes, except for selective deposit feeding nematodes, were highly selective and mainly fed on microphytobenthos, resulting in a high production and a short turn-over time of meiofauna. In conclusion, this thesis demonstrated the important role of meiofauna in soft-bottom habitats as well as the importance of the trophic pathway from microphytobenthos to meiofauna in the functioning of these food webs. 4950 https://nbn-resolving.org/urn:nbn:de:gbv:8-diss-254923$xR$3Volltext$534 4961 https://macau.uni-kiel.de/receive/diss_mods_00025492 5051 570 5550 benthic copepods 5550 benthische Copepoden 5550 community structure 5550 compound-specific isotope analyses 5550 ecological food web model 5550 fatty acids 5550 Fettsäuren 5550 free-living marine nematodes 5550 Frei-lebende marine Nematoden 5550 Gemeinschaftsstruktur 5550 Komponenten-spezifische Isotopenanalyse 5550 microphytobenthos 5550 Microphytobenthos 5550 mudflats 5550 Ökologisches Nahrungsnetzmodell 5550 sandflats 5550 Sandwatten 5550 Schlickwatten 5550 seagrass beds 5550 Seegraswiesen 5550 Stabile Isotopen 5550 stable isotopes