Parameter Tree:
EARTH SCIENCE > BIOSPHERE > ECOLOGICAL DYNAMICS > ECOSYSTEM FUNCTIONS > TROPHIC DYNAMICS

Definition:
Trophic dynamics are major interactions among organisms which involve
feeding relationships. The feeding levels are called trophic levels
where all producers belong to the first trophic level; all primary
consumers (in other words, all herbivores), whether feeding on living or
dead producers, belong to the second trophic level; organisms feeding on
these herbivores belong to the third level, and so on. 


Reference:
Nebel, Bernard J. and Richard T. Wright. Environmental Science: the Way the
World Works.-6th ed. 1998. Prentice Hall, Inc. Upper Saddle River, New Jersey.