Identify the stage of hydrarch succession shown in the figure.

The energy obtained from fossil fuels is essentially a product of which of the following?

Which of the following statements is incorrect regarding the phosphorus cycle?

$A$: In hydrosere,the reed swamp stage is followed by the floating plant stage.
$R$: The sedge meadow stage has amphibious herbaceous plants.

Which ecosystem is more stable?

Which of the following is a primary consumer in a maize field ecosystem?