In the phosphorus cycle, phosphate becomes available by weathering of rocks first to

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.

Which of the following contribute to the carbon cycle?

If plants (producers) of an ecosystem die,then the system

$A$ : During succession,nutrient availability decreases while biomass level increases.
$R$ : $NCP$ (Net Community Productivity) remains same during succession.

From the above given features,how many are associated with primary succession?
Features:
$1$. Occur on newly cooled lava
$2$. Faster succession
$3$. Progress to mesic condition
$4$. Occurs on flooded land
$5$. Slower succession
$6$. Changes in flora only