Why are lichens a good pioneer species after a volcanic eruption?

The pioneer species are defined as those species that are very strong and hardy and also they have the capability of enriching the soil particles that favor their growth and development.

The lichens are considered to be a good pioneer species because they have the ability to settle on the surface of the bare rocks, where they can produce acid that allows the rock to disintegrate and results in the generation of soil particles.

Thus, the lichens are a pioneer species that can evolve rapidly after an eruption of a volcano.

well, i believe that the answer is 2. : 3