What is bare rock succession?

Bare rock succession is a geological process through which an area previously devoid of life becomes capable of supporting plants and other life forms. This generally begins with the establishment of lichens, algae or similar organisms.

Bare rock succession is the product of the accumulation of sand and soil on top of bare rock. As soil builds up, small plants are able to take root. The earliest plants that appear are usually annuals. These plants die and decay each winter, providing the organic matter for more established plants to take root. This process takes hundreds to thousands of years to complete.