Which of the following is $NOT$ a major functional aspect of an ecosystem?

Which one statement is correct regarding man-made ecosystems?

Succession in a $6 \ m$ deep pond exhibits a sequence of

Which one of the following animals may occupy more than one trophic levels in the same ecosystem at the same time?

Which one of the following statements is incorrect for secondary succession?

How many of the following are primary producers in a terrestrial ecosystem?
Herbaceous plants,Algae,Woody plants,Phytoplankton,Aquatic plants