Abstract
Energy flow through the trophic levels was studied at a salt marsh ecosystem distinguished into low and high marsh. Gross primary productions of Suaedeto-Salicornietum and Artemisieto-Limonietum at low marsh were 8, 299 and 13, 154kca/$m^2$/yr, and those of Calama-grostetum and Sonchuso-Setaetum at high marsh were 17, 899 and 15, 177kca/$m^2$/yr, respectively. Efficiencies of solar energy utilization of plants were 1.7 and 2.6% at the former, and were 3.6 and 3.2% at the latter. Of gross productions, net primary productions were 3, 977 and 5, 280kca/m2/yr at low marsh and were 6, 354 and 5, 329kca/$m^2$/yr at high marsh, and the remainder, 52~67%, was consumed by respiration of plants. A small amount (0.03~0.04%) of the net primary production was flowed through grazing food chain and most amout was transferred into dead parts. Of dead parts, 40% was accuulated as litter and the rest was decomposed into detritus. In the detritus food chain, a little energy was utilized by detritus feeder, and a major by microorganism. The amounts of energy flowed through grazing and detritus feeders at high marsh were much more than those at low marsh, but tertary production as spider was Vice versa.