affect ecological processes. During the past 25 years, his work in aquatic ecology has focused on experimental wetland ecology, including the use of wetlands as natural treatment systems for wastewaters.

Odum has authored or coauthored several books that have significantly influenced ecology and related fields. He contributed to the classic ecology text written by his brother, Eugene Odum, also a major figure in ecology in the second half of this century. H. T. Odum's first book, Environment Power and Society (1970), presented a computer language and modeling technique to describe energy flow through ecosystems. The language and modeling approach became the tool of a group of followers who modeled energy flows associated with the movement of commodities in both natural ecosystems and human-dominated systems. This work led to the concept of "embodied energy," since termed "emergy," which accounts for the direct and indirect energy flows (those from "free environmental services" and those supplied by the economy) required to produce a substance. In turn, this led to efforts to conduct economic analyses in terms of energy units.

Odum coined the term ecological engineering in 1962, and he has contributed much to its development as a field distinct from but related to environmental engineering (Mitsch, 1994). He continues to promote the development of university curricula to produce ecological engineers (Odum, 1994). Odum has received many awards, including the Mercer Award of the Ecological Society of America; the AIBS (American Institute of Biological Science) Distinguished Service Award; the Prize of the Institut de la Vie, Paris; and the Crafoord Prize of the Swedish Academy of Sciences. The last two prizes were shared by the two distinguished brothers, H. T. and Eugene.