In which form can the productivity of ecosystems be compared?

What is $NPP$?

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.

The storage of energy at the consumer level is known as:

The annual net primary productivity of the whole biosphere is approximately $...........$ (dry weight) of organic matter.

Which of the following ecosystems has the highest primary productivity?