Patterns and causes of spatial heterogeneity in abundance and diversity of meiofauna in a tidal flat system
Steyaert, M.; Moens, M.; Cattaert, S.; Vincx, M. (1998). Patterns and causes of spatial heterogeneity in abundance and diversity of meiofauna in a tidal flat system. Biol. Jb. Dodonaea 65: 175
Also appears in:Beeckman, T.; Caemelbeke, K. (Ed.) (1998). Populations: Natural and manipulated, symposium organized by the Royal Society of Natural Sciences Dodonaea, University of Gent, 29 October 1997. Biologisch Jaarboek (Dodonaea), 65. Koninklijk Natuurwetenschappelijk Genootschap Dodonaea: Gent. 257 pp., more
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| Keywords |
Abundance
Aquatic communities > Benthos > Meiobenthos
Conferences
Topographic features > Landforms > Coastal landforms > Tidal flats
Marine/Coastal |
| Authors | | Top |
- Steyaert, M.
- Moens, M., more
- Cattaert, S., more
- Vincx, M., more
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| Abstract |
The variability of abundance, species composition, and feeding group distribution of the metazoan meiofauna (organisms < 2mm) was analysed on the Molenplaat, a tidal flat in the Westerschelde Estuary, at different spatial scales: vertically to within half a centimetre and horizontally at scales of centimetres to kilometres. The most striking spatial heterogeneity was detected at the km scale and resulted from important differences in granulometry. The siltier sediments were characterized by species typically found in fine-grained, detritus rich sediments, with all nematode trophic groups evenly represented. The bulk of the organisms were restricted to the upper 5 mm of the sediment. Conversely, the fine sandy sediments showed a more uniform vertical abundance distribution of the meiofauna, but important differences in the relative proportions of feeding groups: the top two cm were dominated by the predatory nematode Enoploides longispiculosus, while Metadesmolaimus pandus, a deposit feeder, was dominant in deeper layers. Analysis of a set of benthos samples covering 10 cm2 and 1,25 cm2 areas failed to reveal significant correlations between the abundance of major meiofaunal taxa and phytopigment or bacterial concentrations, except for Ostracoda, which positively correlated with diatom densities (as indicated by fucoxanthin concentration) on the smaller scale. In addition, total meiofauna and nematodes in the 1,25 cm2 samples correlated at p < 0,1 to the ratio of fucoxanthin to chla, suggesting the relative proportion of diatoffis in total microalgae to be a potentially important factor determining meiofaunal abundance. It is expected that a more detailed taxonomic analysis of the meiofauna (i.e., to the species level) and of more phytopigments, representative of other microalgal groups or equilibria, will be able to illustrate significant relationships between meiofauna and microalgae. |
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