02485nas a2200265   4500008004100000245011800041210006900159300001300228490000800241520163600249653001801885653001001903653001001913653001501923653002301938653001901961100001801980700001701998700001702015700001602032700001702048700001602065700001302081856012502094       1996                        eng d00aThe relationship of floods, drying, flow and light to primary production and producer biomass in a prairie stream0 arelationship of floods drying flow and light to primary producti  a151 -1590 v3333 aFactors related to autochthonous production were investigated at several sites along a prairie stream at Konza Prairie Research Natural Area. Primary production, algal biomass, litter input, and ability of floods to move native substrate were measured. Additional experiments were conducted to establish the influence of light and water velocity on primary production rates and recovery of biomass following dry periods. The study period encompassed two extreme (> 50 year calculated return time) floods, thus we were able to analyze the effects of scour on periphyton biomass and productivity. Biomass of sedimentary algae was reduced greatly by flooding and did not reach preflood amounts during the 2 months following the first flood. Rates of primary production associated with sediments recovered to levels above preflood rates within 2 weeks. Biomass of epilithic periphyton was not affected as severely as that of sedimentary algae. Little relationship was observed between water velocity and photosythetic rates. Production reached maximum rates at 25% of full sun light. Epilithic chlorophyll levels recovered within eight days following a dry period, and chl a was an order of magnitude greater on rocks than sediments 51 days after re-wetting. Estimated annual rates of primary production were 2.6 times greater in the prairie than in the forest reaches of the stream. The ratio of annual autochthonous:allochthonous carbon input was 4.81 for prairie and 0.32 for the forest. Periphyton production in prairie streams is resilient with regard to flooding and drought and represents a primary carbon source for the system.10aautochthonous10aFlood10alight10aperiphyton10aPrimary production10awater velocity1 aDodds, W., K.1 aHutson, R.E.1 aEichem, A.C.1 aEvans, M.E.1 aGudder, D.A.1 aFritz, K.M.1 aGray, L.  uhttp://knz.lternet.edu/content/relationship-floods-drying-flow-and-light-primary-production-and-producer-biomass-prairie