Biogeochemical Cycling - Nutrient Cycles
The energy flows through ecosystems enabling the organisms to perform various kinds of work, and is ultimately lost as heat. It is gone forever in terms of usefulness to the system. On the other hand, nutrient materials never get 'used up'.
They can be recycled again and again indefinitely. For example when we breathe, wk inhale several million atoms that may have been inhaled by say, Akbar or any other person you may care to choose from history. First let us explain .what we mean by mineral nutrients. More than 100 chemical elements, about 40 are present in living organisms. Some are needed in relatively large amounts and n, are called macronutrients while some are needed in only trace amounts and so named micronutrients.