In Hawaii, there are volcanoes. Before anything was there, the volcanoes erupted which produced volcanic rock. Lichens were the first species to arrive, and they broke down the rock into soil. Eventually, shrubs began to grow and, later, trees grew there. Now, the islands are functioning at their climax community.
What is the pioneer species in this example?

A. Shrubs
B. Lichens
C. Trees
D. Rock

Lichens

Explanation:

The Volcanic eruption had rendered the land into a barren environment . A new habitat was formed due to the volcanic eruption that occurred.

A pioneer species is the first species that colonize a barren environment or damaged ecosystem.  The pioneer species prepare the environment for other incoming organism to be able to exist. Pioneer species are hardy organisms.

The lichen in this case was the first to arrive in the disturbed ecosystem(volcanic erupted area) . The lichen establish the place for a higher level of succession . The lichen provide organic matter for other higher level of succession to occur such as shrubs and later trees