Question

How do organisms contribute in the formation of soil?

Answer 1

Living organism contribute to the formation of soil by performing biological weathering. In biological weathering, the living organisms secrete chemical secretions that help in the breakdown of large rocks into smaller fragments. Typical examples of organisms that help in soil formation are Lichens and Bryophytes.

Lichens induce biological weathering by extracting minerals from the rocks, which results in the formation of small cervices that serve as the site for soil formation.

Bryophytes can readily grow in the cervices formed by lichens and further deepen the cervices. These deeper cervices form cracks. In due course of time, because of growth of bigger plants, rocks eventually pulverise and form soil.