If a $succession$ occurs in a $hydric$ (aquatic) area,the final climax community will be .....

$A$ community which starts succession in a habitat is

Composition and structure of communities constantly change in response to the changing environmental conditions. These changes lead finally to a community that is in near equilibrium with the environment and that is called a.......

$A$ community that is in equilibrium with the environment is called $..............$.

What are ecosystem services?

Out of the total cost of various ecosystem services, the soil formation accounts for $P$, while contributions of other services like recreation and nutrient cycling are less than $Q$ each. The value of climate regulation and habitat for wildlife is about $R$ each. Identify $P, Q,$ and $R$.