What is formed by the interactions between biological communities and their environment?

$A$: Stratification helps in the accommodation of a large number and types of plants in the same area.
$R$: It is the occurrence of horizontal zonation in the ecosystem.

What percentage of incident solar radiation is included in $PAR$ (Photosynthetically Active Radiation)?

Which of the following is considered an artificial ecosystem?

In an ecosystem,the vulture is a/an .......

Each trophic level has a certain mass of living material at a particular time,which is known as $..........$.