Diversity-productivity relationships in estuarine microphytobenthos

Field studies at three intertidal mudflat stations within the Scheldt Estuary indicated an inverse relationship between microphytobenthos biomass and species diversity, while the relationship between diversity measures and primary productivity appeared to be site specific, with either a significant positive or a unimodal relationship between both parameters. Species counts and molecular fingerprinting using DGGE were largely congruent and revealed that taxonomic turnover among eukaryotic microbenthos is largely determined by salinity, water content, temperature, irradiance, and tidal elevation. Experimental studies revealed significant cryptic diversity among diatoms and demonstrated that both facilitative and antagonistic interactions play an important role in structuring microphytobenthos communities. Species interactions need to be taken into account when studying critical ecosystem processes such as productivity, stability, sediment stabilization and nutrient cycling in marine and estuarine sediments