In a pond ecosystem,benthos means

Phytoplankton $\rightarrow$ Submerged plant stage $\rightarrow$ Floating plant stage $\rightarrow$ Reed-swamp stage $\rightarrow$ Marsh-meadow stage $\rightarrow$ Scrub $\rightarrow$ Forest. What type of succession does this sequence represent?

Which process is responsible for the structure of an ecosystem?

The cycling of elements in an ecosystem is called:

$...........\%$ of the total global carbon is found dissolved in the oceans. (in $\%$)

$A$ biogeochemical cycle without an atmospheric component is