Abstract: This paper introduced a series of concepts and methods of network trophic dynamics in ecosystem ecology.Transfer efficiencies and utilization efficiencies were developed from first principle of thermodynamics and shown to be extensions and generalizations of progressive efficiency to trophic networks.The concept of trophic partitioning of compartment into different trophic levels was implemented through the “ unfolding”of trophic networks according to the past history of energy(matter)within the system,Several indices characterizing trophic structure of the system were also summarized.

Key words: denitrifying bacterium, screening,  , denitrification rate, anaerobic ammonium oxidation.