Floodplain lakes primary production

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... 

The total organic carbon balance for lakes on the central Amazon floodplain can be examined by comparing total inputs due to primary production and external loading with total losses (Table 14.4). The combined input of organic carbon due to primary production, river import and local runoff was estimated at 117.3 Tg C yr. Combined losses due to biogenic gas emission 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. 

Schmidt, G. W. 1973. "Primary production of phytoplankton in the three types of Amazonian waters. 3. Primary productivity of phytoplankton in a tropical floodplain lake of Central Amazonia Lago Castanho, Amazonas, Brazil." Amazoniana 4 379-404. 

Closed systems, such as the wetlands that receive most of their water from precipitation (e.g., bogs, pocosins, and some seasonal or ephemeral wetlands), are oligotrophic and typically have low primary productivity. Increased inputs from surface and ground water can increase primary productivity in fens and marshes. (Table 5.5) Wetlands that receive pulses of nutrients, such as river floodplains, littoral zones in lakes, and tidal marshes, are typically very productive (Sharitz and Pennings, 2006). 

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