Three species of aquatic macrophytes from an agricultural drainage ditch were analyzed for N, P, and organic C throughout the 1976 growing season. These macrophytes accumulated large amounts of these nutrients, averaging 26.49 mg N g-1 dry weight, 5.89 mg P g-1 dry weight and 353.7 mg C g-1 dry weight. Measured breakdown rates of Potamogeton nodosus Poir. were 0.0312 d-1 and 0.0408 d-1 at two different sites. C:N of the decaying macrophytes was less than 17:1 throughout the study. Analyses of covariance of the nutrient accumulation and breakdown of aquatic macrophytes revealed no differences among species or sites.
Bibliographical noteFunding Information:
This research was funded from three grants to Dr. Henry W. Quade, Department of Biology, Mankato State University. These included funds from Tetonka Lake Association, Inc.; a State of Minnesota Natural Resources Grant (Restoration Demonstration); and a Mankato State University Faculty Research Grant. The author thanks the above for their support, and is also grateful for the critical review of this manuscript by Dr. Jackson R. Webster, Virginia Polytechnic Institute and State University.