Precipitation, runoff, and drainage supplied about 1.5 metric tons of NH4-N, 4.1 metric tons of N03-N, and 0.09 metric tons of P04-P to Eagle Lake in 1976. Shoots of Typha glauca, Carex atherodes, Sparganium eurycarpum, and S cirpus validus had ac­ cumulated 18.0 metric tons of N and 1.8 metric tons of P at peak standing crop in late July. During decomposition, shoots of all four species lost organic matter faster than P, and lost P faster than N. Carex, Typha, and Scirpus litter were more effective in retaining or accumulating N and P than was Sparganium litter.