In ecological crisis, whom interference play important role

Justify the following statement in terms of ecosystem dynamics. “Nature tends to increase the gross primary productivity, while man tends to increase the net primary productivity”.

Trophic levels are formed by

Choose correct answer.

$(1)$ Zooplanktons are primary producers in an aquatic ecosystem.

$(2)$ Decomposition is largely an oxygen requiring process.

$(3)$ In a natural ecosystem, fishes, wolf, etc. are carnivore.

$(4)$ The amount of energy decreases in each successive trophic level.

Identify the possible link “$A$” in the following food chain.

Plant $→$ Insect $→$ Frog $→$ “$A$” $→$ Eagle