What is the origin of pioneer species in primary succession

Pioneer species in primary succession can begin from rock formation such volcanoes or in a place where there is no soil or organisms. The species that normally arise first in the place of primary succession are lichens and mosses; because of this they are refereed to as pioneer species.
In a situation where a primary succession is growing from a bare rock, the pioneer lichen may come from the lichen that colonize the rock.