The energy or biomass remaining after heterotrophic respiration is called ..........?

The amount of biomass or organic matter produced per unit area over a time period by plants during photosynthesis is called:

The net primary productivity of an ecosystem is:

In an ecosystem,the rate at which organic molecules are synthesized from solar energy is known as:

Maximum productivity is found in

Which of the following ecosystems will be more productive in terms of primary productivity? Justify your answer: $A$ young forest,a natural old forest,a shallow polluted lake,an alpine meadow.