I am trying to understand the Universal model of energy flow by Odum.
In this linked diagram I is the input energy(the amount of energy present in the food consumed by this tropic level, say its, the 2nd tropic level, the herbivores), part of this food is excreted as undigested food (the NU) , the rest is digested, absorbed and assimilated reaching the cells and then the energy accumulated at cellular level is called the assimilated energy (A). Now part of A is utilised to make ATPs that are being used to fuel the metabolisms occurring in the organisms which is represented by R and the rest is available to the next tropic level(?) as P ?
Then what makes the standing biomass? The organisms the are not eaten up?
Besides I don't understand the Energy Storage part. What physiological process corresponds to this?