Question

What is a trophic level in an ecosystem? What is 'standing crop' with reference to it?

Answer 1

A trophic level is a level of species in an ecosystem on the basis of the source of nutrition such as producers, primary consumers, secondary consumers, etc.

The producers form the first trophic level as they manufacture food. The primary consumers form the second trophic level, the secondary consumers form the third, and the tertiary consumers form the fourth trophic level. 

Standing crop is the quantity or total weight of dried biomass of the organism which is present in a specific location at a particular time. 

Each tropic level has a certain mass of living material at a particular time called as standing crop. It is measured as the mass of living organism or the number in a unit area.