Size structure of the metazoan community in a Piedmont stream.

摘要: We characterized the size structure of virtually entire metazoan community in a fourth order, sandybottomed Piedmont stream during late summer. Our study, first to sample across all habitat types and sizes metazoans an aquatic ecosystem, indicates that at level, spectra may be bimodal for benthos or trimodal when fish are included. Animals spanning 10 orders magnitude dry mass (from gastrotrichs fish) were quantitatively collected from nine types. The benthic spectrum was by meiofaunal component (mostly oligochaetes micro-crustacea) macrobenthic introduced asiatic clam, Corbicula fluminea). Insects contributed little overall standing crop. Size-specific contribution whole-community metabolism assessed using allometric equations respiration, we found distinctly distribution range, with peaks macrofaunal ranges. is similar observed marine but not other freshwater systems, possibly because range and/or animal sampled latter. Numerous factors influence ecosystems, including local geomorphic (habitat) conditions, water level fluctuations, species introductions, predation processes.