An example of biological weathering is the widening of gaps
in rocks caused by tree roots since pressure or stress is exerted on the
rocks due to the growing plant roots. The pressure is exerted by a biological
process (i.e., growing roots), even though the process is physical.
Plants and animals and its action speeds up mechanical and or
chemical weathering, which in turn causes biological weathering.
With the help of the chemicals
that are produced by the tiniest bacteria, algae and liches, the rocks which they
live in are also broken down by them in order to get the nutrients they need.
