Periphyton production

As is evident throughout our review, a much wider diversity of lakes and floodplain environments must receive the attention of limnologists. Additional measurements of periphyton productivity, of burial of C, N, and P in sediments, of nitrogen fixation and denitrification, and of carbon dioxide emissions, especially, are needed. A further challenge is to investigate biogeochemical processes in the ATTZ, and to link these processes with the whole floodplain ecosystem. 

Periphyton is abundant in oligotrophic areas of the Everglades and is responsible for significant primary production and phosphorus storage. In these systems, periphyton productivity and tissue phosphorus concentration are strongly related to phosphorus concentration of the water column. 

Elwood and Nelson (1972) described another study of periphyton, utilizing the same field methods as in the previous study, in which periphyton production and grazing rates were measured. Their concluding statement was ... 

Elwood, J. W., and D. J. Nelson. 1972. Periphyton production and grazing rates in a stream measured with a P material balance method. Oikos 23(3) 295-303. 

In chapter 14, John Melack and Bruce Forsberg provide a quantitative assessment of the role of floodplain lakes in regional cycles of C, N, and P. Floodplain lakes were found to be important centers of organic carbon production and delivery to the river system. The combined primary production of macrophytes, forests, periphyton, and plankton associated with floodplain lakes is estimated at 117 Tg C yri, of which only 24% is remineralized in the lakes. As a result, an estimated 90 Tg C yr are delivered to the river system by continual and seasonal exchanges. This input alone amounts to... 

Putz (1997) estimated production as uptake of i C by periphyton that grew on artificial cellulose-acetate substrata suspended in several habitats near Manaus. Her results could not be used to compute an areal value for periphyton associated with floating macrophytes due to the complex surface of the natural substrata. To extrapolate her results to areal rates in floodplain forests requires an estimate of leaf area in the euphoric zone per unit area of water. Alves (1991) reported between about 0.5 and 1.5 m2 of leaves in the euphoric zone of flooded forest per m2 of water for simplicity we used 1.0. Based on net productivities measured by Putz (1997) at a site dominated... 

For the entire floodplain herbaceous macrophytes accounted for the largest share of total primary production, 65%, followed by floodplain forests, periphyton and phytoplankton which accounted for 28%, 5% and... 

Doyle, R. D. 1991. Primary production and nitrogen cycling within the periphyton community associated with emergent aquatic macrophytes in an Amazon floodplain lake. Ph.D. Thesis, University of Maryland, p. 269. 

Putz, R. 1997. "Periphyton communities in Amazonian black-and Whitewater habitats Community structure, biomass and productivity." Aquatic Sciences 59 74-93. 

Enzyme assays Heterotrophic respiration UV absorbance Biological Nj fixation Periphyton community composition Primary productivity Diel pH and dissolved oxygen... 

Suitability of the method of measuring primary productivity for autotrophs other than phytoplankton has been investigated. Wetzel (1966) summarizes the literature for the use of this method with periphyton and higher aquatic plants. He discusses applications in both the field and the laboratory. It is obvious that determination of primary productivity in periphyton and higher aquatic plants is more difficult than in phytoplankton. 

This material balance method would appear to have wide application for studying process rates in natural streams regardless of their location since less than maximum permissible concentrations of were used while radionuclide levels in periphyton and water were sufficient to monitor for at least six weeks following the release.. . . Since P has a short physical half-life (14.3 days), there is no danger of high residual concentrations in a stream ecosystem following the release because of radioactive decay. Thus, repeated releases may be made to the same stream to determine changes in biomass, primary production rate, and primary consumption rate on a seasonal basis. 

Wetzel, R. G. 1966. Techniques and problems of primary productivity measurements in higher aquatic plants and periphyton, pp. 249-267. In Primary Productivity in Aquatic Environments (C. R. Goldman, ed.). University of California Press, Berkeley. 

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