Which of the following does not effect the forest ecosystem

$A$ : Successional process starts only in those areas, where no living organisms ever existed.

$R$ : These areas are not supported by physical environmental conditions.

Gaseous type of nutrient cycles are .......

According to Robert Constanza average price tag for ecosystem services is

Tropical rain forests are found in

Vertical distribution of different species occupying different levels in a biotic community is known as