When you picture the lowest levels of the food chain, you might imagine
herbivores happily munching on lush, living green plants. But this
idyllic image leaves out a huge (and slightly less appetizing) source of
nourishment: dead stuff. John C. Moore details the "brown food chain,"
explaining how such unlikely delicacies as pond scum and animal poop
contribute enormous amounts of energy to our ecosystems.
Via Eric L Berlow, Complexity Digest