Community structure. The habitats of benthic assemblages are structured, their species richness (biodiversity, alpha-diversity) and ecological diversity regulated by the interaction of ecological and physical processes. Therefore, some basic questions are: what are those structuring factors? Why is it that sandy bottoms tend to harbor more meiofauna species than muddy bottoms? There are no generally valid answers to these questions. Many scientists contend that biotic factors such as food supply, predation, competition, and reproductive strategies are decisive; others emphasize the impact of abiotic parameters such as exposure, temperature and salinity. Of course, there are good examples of both of these positions in the ecology of meiobenthos. The conclusions depend much on the area investigated (exposed vs. sheltered habitats), the taxonomic and ecological nature of the animals studied (opportunists vs. specialists), and the methods used (life vs. fixed; sieving vs. sorting).
In stable environments such as sheltered flats, nontidal seas, groundwater systems and deep-sea bottoms, biotic factors will have the stronger structuring effect on meiofauna. In extremely stable ecosystems, competitive interactions may induce instabilities in conflicting populations and ultimately cause the displacement (“amensalism”) of the less competitive species. According to the time-stability hypothesis, this means that biotope stability would reduce diversity (Rhoads and Young 1970; Woodin and Jackson 1979a,b; Warwick et al. 1986b).
KeywordsSize Spectrum Harpacticoid Copepod Taxonomic Distinctness Benthic Ecosystem Life History Data
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