Question

In ecological succession the first living things to colonize a hitherto barren area is called a

Answer 1

Pioneer organism

Step-by-step explanation:

A pioneer organism is an organism that populates a barren region for the first time. This is the case after the life in a particular region has been destroyed (such as after a natural disaster, a mass extinction, or any other similar event). Some organisms are more commonly pioneer than others, as their adaptability is particularly high. This includes lichens and algae.

Answer 2

Answer is: Pioneer organism.
Pioneer organism or disaster taxon is an organism that populates a region after natural disaster or mass extinction. Pioneer organisms are usually lichens, algae, mosses, birds.