TROPHIC CIRCULATION IN ECOSYSTEMS

The trophic aspect of ecology has been studied for more than six decades; in this contribution we address theoretical aspects relative to the concept of trophic flow at the ecosystem level and from the thermodynamics point of view. Much of this knowledge is greatly based on the consideration that ecosystems are functional units that are worth global study. Undoubtedly, a key element in the study of ecosystems relates to energy circulation through food webs. Although trophic ecology has been a suffciently studied topic, we have not found a formal description of the trophic flow concept. Thus, this work proposes a concept based on movements of matter and energy amongst the biological components of the ecosystem. We include Odum's universal model of energy flow to synthesize the concept of trophic flow in the ecosystem. Additionally, we analyze the ecosystem thermodynamics, we discuss the characteristics of ecosystems as open and dissipation systems, and we indicate which types of mechanisms can regulate trophic flow in ecosystem. Finally, we discuss how the study of trophic flow is helpful for characterization of ecosystems structure and function, and it is important to consider it in ecosystems-based management as well.