$A$: $A$ stable community should show much variation in year-to-year productivity.
$R$: It must not be resilient to occasional disturbance.

Arrange the stages of hydrarch succession in the correct sequence.

Which of the following is an example of a man-made ecosystem?

Which of the following statements are correct regarding a food chain?
$(a)$ If $80\%$ of tigers are removed from an area,the growth of vegetation in that area increases.
$(b)$ If carnivores are removed from an area,the population growth of deer increases.
$(c)$ The length of a food chain is limited to $3$ to $4$ trophic levels because the amount of energy decreases in the ecosystem.
$(d)$ The length of a food chain is usually $2$ to $8$ trophic levels.

Which among the following is not a functional unit of the ecosystem?

Which of the following biochemical cycles has a gaseous phase?