According to $David \ Tilman$,greater the diversity,greater is the primary productivity. Can you think of a very low diversity man-made ecosystem that has high productivity?

Some of the stages in the hydrarch succession are labelled as:
$I.$ Marsh meadow stage
$II.$ Reed swamp stage
$III.$ Submerged plant stage
$IV.$ Phytoplankton stage
$V.$ Submerged free floating plant stage
Identify the choice that represents the correct sequence of these stages.

The hydrological cycle comprises two overlapping cycles.

The dynamic system of an ecosystem depends on which of the following?

The following diagram shows the phosphorus cycle. Identify the producers in it.

The importance of an ecosystem lies in