A reproduction of the biomass pyramid for the Silver Springs community that appeared as Fig. 21 in Odum's Silver Springs paper. Abbreviations P, H, C, TC, and D refer to primary producers, herbivores, carnivores, top carnivores, and decomposers. (Source: W.M. Kemp and W.R. Boynton, 2004, Productivity, trophic structure, and energy flow in the steady-state ecosystems of Silver Springs, Florida, Ecological Modelling, 178:43–49. Numbers in the figure have units of dry biomass (gm^?2).

Silver Springs, Florida ( 29°12'59.00"N, 82° 3'10.13"W) is a historical ecosystem that was the site for the famous study done by scientist H.T. Odum on trophic energy flows that would later greatly influence development of the field of ecosystem ecology. Silver Springs, located in north-central Florida, serves as the largest and most well-known spring in the region. Odum’s Silver Springs study was conducted during the years 1951 to 1956. He chose to focus his study on the main boil where upwelling occurs in the spring and river and also on the beginning 0.75 miles of the outflow water stream. Odum’s objective was to develop a system for quantifying the energy flow between different trophic levels, and to study the efficiency of the ecosystem’s constant productivity output.

Odum found that the energy flow of the Silver Springs ecosystem remained stable because of the regular addition of inorganic nutrients that are transformed into biomass and ultimately result in an outflow of organic matter from the system. Odum believed that this long-term stable state of Silver Springs had enabled the ecosystem to produce an optimal efficiency of its power output through its ability to use time proficiently to regulate changing physical and biological conditions. Odum’s Silver Springs study also focused on calculating the primary production and respiration rates of the ecosystem - findings that have since served as a model for studies of trophic energy flow in streams. Many of Odum's techniques, as well as conclusions drawn from this study, are presently used to identify the energy flow and trophic structures of different ecosystems around the world. The current international focus on the biosphere's net carbon balance has roots in Odum’s study of the small streams within Silver Springs.

Further Reading

• Howard T. Odum Collection
• Odum, H.T., 1957a. Trophic structure and productivity of Silver Springs, Florida. Ecol. Monogr. 27, 55–112.
• Odum, E.P., 1968. Energy flow in ecosystems: a historical review. Am. Zool. 8, 11–18.
• Odum, H.T., Johnson, J., 1955. Silver Springs and the balanced aquarium controversy. Sci. Counsel. 18, 128–130.