Answer: Acids
Explanation:
Lichens and mosses are the two plant species which belong to the plant kingdom Bryophyta. These are the two early species which colonize over a barren land. They make the environment suitable for the survival of other species. The Lichens firstly colonize over the rocks and they secrete acids which helps in the withering process of rocks into fine particles of soils. This facilitates the growth of small mosses. This helps in improving the quality of soil so that more plants can grow over it.
