How is thr majority of carbon transfered from plants and animals to the soil?
The majority of carbon is transferred from plants and animals to the soil through a process known as decomposition. When plants and animals die, their organic matter, which contains carbon, undergoes decomposition by microorganisms such as bacteria and fungi. These decomposers break down the organic matter, releasing carbon dioxide (CO2) as a byproduct. This released CO2 can either be released into the atmosphere or can be absorbed by plants through photosynthesis, leading to the carbon being cycled back into the plant system.
During decomposition, part of the carbon is converted into stable carbon compounds such as humus, which forms a major component of soil organic matter. Humus is a dark, organic substance that helps to improve soil structure, water retention, and nutrient availability. Over time, these stable carbon compounds can remain in the soil for several years to centuries, effectively transferring carbon from the plant and animal system to the soil.
In addition to decomposition, plant roots also play a role in carbon transfer to the soil. Through a process called root exudation, plants release organic compounds such as sugars, amino acids, and organic acids into the soil. These compounds provide energy sources for soil microorganisms, promoting their growth and activity. In this process, some of the carbon found in plants is directly transferred to the soil through root exudates.
Overall, the decomposition of dead organic matter and the release of root exudates are the main mechanisms by which carbon is transferred from plants and animals to the soil.