Question

How can moss and lichen, which may grow in the beginning of primary succession, potentially make it easier for other organisms to grow and live in the same area later on?

Answer 1

Lichens that colonize bare rock secrete acids that break down the rock and start the soil-production process. Also, as lichens die, they provide some organic matter that also contributes to soil. Mosses can then colonize the thin soil; as mosses die, the soil thickens more allowing other hardy species to colonize.