Grassland biome for its maintenance requires

Identify the correct sequence of development of a stable community (climax community) starting from a new area (primary succession).

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

Select the incorrect match.
$I.$ Sedimentary nutrient cycle-Nitrogen cycle
$II.$ Pioneer species-Lichens
$III.$ Secondary succession-Burned forests
$IV.$ Pyramid of biomass in sea-Upright

The bulk fixation of carbon through photosynthesis takes place in

$X-$ Atmospheric input of phosphorus through rainfall is much smaller than carbon input.
$Y-$ The exchange of phosphorus between organisms and the environment is negligible.