What is biological weathering? Explain the significance. What is the impact of this process in Orange County? (Human-environmental interaction, for instance)

 

The process of weathering when caused by living organism is called as Biological Weathering.

• The roots of plants causes biological weathering by growing through joints, cracks and bedding plane of rocks which ultimately breaks them apart and detach them as sediments and soil. This is mainly attributed by the release of acidic chemical agents by the roots. This is called as Mechanical fracturing aided by chemical agent.
• In addition, the burrowing activity of small animals also contributes to biological weathering.
• The breaking and widening of rocks further allows water to percolate and promote physical weathering.
• Other organisms such as bacteria, fungi and lichens also releases weak acidic compounds which causes chemical reactions promoting dissolving of rocks.
• It involves breakdown of minerals at molecular level. For instance - Rock surfaces are inhabited by lichens which gradually eats/corrodes the it through release of acidic compounds.

Significance of Biological Weathering :

• The process of biological weathering promotes breakdown of rocks to provide sediments and soil; allows movement of minerals obtained from the process of weathering; facilitates mixing of minerals and promotes existence of life.
• The sediments and soil obtained by weathering contains essential elements required by all living organism (Helps gaining Nutrients).
• Accumulation and transfer of minerals necessary for existence of life.
• It assists formation of smaller crevices that allows further growth of rootlets.

With reference to human environment interaction the process of biological weathering plays an important role. The biological activity of organisms assists the physical and chemical processes required for weathering. The continuous harvesting of minerals for human activities from the soil requires gradual fresh supply of nutrients which is aided by the process of weathering. The minerals made available by this process are used for agriculture, building process, medicinal and many more activities