02937nas a2200229 4500008004100000245009500041210006900136300001200205490000700217520214000224653003102364653001602395653001302411653003702424653001902461653001902480653002502499653002202524100002002546700001702566856012402583 2002 eng d00aMacroinvertebrate production and trophic structure in a tallgrass prairie headwater stream0 aMacroinvertebrate production and trophic structure in a tallgras a97 -1130 v213 aResearch on North American prairie stream communities has lagged behind other regions. We examined the ecosystem significance of the macroinvertebrate community of riffle/run habitats in Kings Creek, a 2nd-order tallgrass prairie stream at Konza Prairie Biological Station (Kansas, USA), by estimating secondary production, benthic organic matter standing stocks, and resource consumption and egestion by functional groups. Annual mean standing stock macroinvertebrate biomass was 2.3 g ash-free dry mass (AFDM)/m2, annual production was 19.7 g AFDM m-2 y-1, and the annual community production/biomass (P/B) ratio was 8.6. Macroinvertebrate production was higher than published estimates for forested streams of similar size, but much lower than that of a Sonoran desert stream. Distribution of production among functional groups was 30% for collector-gatherers, 9% for collector-filterers, 20% for scrapers, 23% for shredders, and 18% for predators, resembling estimates from some forested streams with the exception of higher scraper production. Although detritivorous groups were productive in this prairie stream, they appeared food limited. Consumption estimates indicated shredders and collector-gatherers annually ingested ∼80% and ∼240% of coarse particulate organic matter (CPOM) and fine particulate organic matter (FPOM) standing stocks, respectively. Thus, re-ingestion and/or diet shifts may be common, particularly among collector-gatherers, and the FPOM pool must turn over rapidly. Invertebrate predators also consumed a sizeable portion (∼52%) of prey, whereas scrapers (∼21%) and filterers (<1%) consumed relatively small portions of their respective resources, suggesting top-down influences on these groups. This study indicates that, during a period of relatively stable flow in this prairie stream, macroinvertebrate production and functional structure were roughly intermediate between North American forested and desert systems. Our results underscore the value of secondary production estimates for examining invertebrate communities in an ecosystem context10aAquatic macroinvertebrates10aEnergy flow10aFood web10aKonza Prairie Biological Station10aorganic matter10aPrairie stream10asecondary production10aTrophic structure1 aStagliano, D.M.1 aWhiles, M.R. uhttp://lter.konza.ksu.edu/content/macroinvertebrate-production-and-trophic-structure-tallgrass-prairie-headwater-stream