General prefixes:
* Overpopulation: Excessive population in a given area.
* Underpopulation: Insufficient population for a given area.
* Depopulation: Reduction in the number of people in a place.
* Repopulation: The process of re-establishing a population in a place.
More specific prefixes:
* Subpopulation: A smaller group within a larger population.
* Interpopulation: Relating to relationships between different populations.
* Prepopulation: The population that existed before a specific event or time period.
You can also use prefixes to indicate a particular type of population:
* Animal population: The number of animals in a given area.
* Plant population: The number of plants in a given area.
* Human population: The number of people in a given area.
The best prefix to use will depend on the context of your writing.