During ecological succession,

What is a biogeochemical cycle? What is the role of the reservoir in a biogeochemical cycle? Give an example of a sedimentary cycle with a reservoir located in the Earth's crust.

$A$ farmer harvests his crop and expresses his harvest in three different ways.
$(a)$ $I$ have harvested $10$ quintals of wheat.
$(b)$ $I$ have harvested $10$ quintals of wheat today in one acre of land.
$(c)$ $I$ have harvested $10$ quintals of wheat in one acre of land,$6$ months after sowing.
Do the above statements mean one and the same thing? If your answer is yes,give reasons. If your answer is 'no',explain the meaning of each expression.

What proportion of the total solar radiation is received as $PAR$?

At which latitude is the heat lost by insolation approximately equal to the heat lost by terrestrial radiation?

$A$ $Climax$ community is defined as ...