The following are the effects of living organisms on the weathering process
- Small plants (lichens) colonise bare rocks whose roots penetrate into rocks making cracks into them.
- Vegetation cover breaks down and adds organic matter in the soil.
- Plant roots penetrate the cracks in rocks and as they enlarge, they widen the cracks leading to breakdown of rocks
- Some microorganisms like Rhizobia bacteria spp fix Nitrogen into the soil which enables plants to grow well.
- The tips of plant roots secret chemicals which dissolve the mineral components of rocks, as a result rocks are weakened
- Soil living organisms feed on organic matter thereby decomposing it
- Large animals break down rocks as they walk over them
- Organisms like termites and earthworms break down soft rocks and they also help in mixing underground soils with top soil and nutrient recycling
- When living organisms die, they increase the organic matter content in the soil.