Distribution and seasonal occurrence of the hyporheic fauna in a northern California stream

摘要: The surface and hyporheic fauna of a second-order reach northern California Coast Range stream (Big Canyon Creek, Lake Co., CA, USA) was examined using substrate colonization samplers (i.e. pots) during both the wet dry seasons in prevailing Mediterranean climate region. In terms total number macroinvertebrate taxa, (0 cm to −5.0 within substrate) level had higher richness than any (−5.1 −15.0 cm, −15.1 −25.0 or −25.1 −35.0 cm) from beginning season (May) (October); this period not subject disturbance wet-season storms. During season, at similar that observed three levels examined. Macroinvertebrate density substantially reduced season; however, mean densities always exceeded those found zone (from 25% 78% numbers were surface). Seasonal fluctuations abundance macroinvertebrates many constituent populations less surface. Apparently, early instars abundant taxa do penetrate interstices, due spates is deeper levels. Compared with faunas described other temperate-zone sites, community shows numerical dominance by Chironomidae.