Decomposition in nature - SS2 Biology Lesson Note

Decomposition is a fundamental process in nature that involves the breakdown of organic matter into simpler substances. It plays a crucial role in nutrient cycling and the recycling of essential elements in ecosystems. Decomposition occurs through the actions of various organisms, primarily decomposers such as bacteria, fungi, and detritivores.

Here's an overview of the decomposition process:

1.       Detritus Formation: The process begins when plants and animals die, shed leaves, or produce waste materials. The dead organic matter, known as detritus, consists of complex compounds like proteins, carbohydrates, and lipids.

2.       Fragmentation: Initially, larger organisms like earthworms, millipedes, and arthropods break down the detritus into smaller pieces through physical fragmentation. This process increases the surface area available for microbial decomposition.

3.       Chemical Decomposition: Decomposers, mainly bacteria and fungi, colonize the detritus and start breaking down complex organic compounds into simpler substances through chemical decomposition. These microorganisms secrete enzymes that break down proteins into amino acids, complex carbohydrates into simple sugars, and lipids into fatty acids and glycerol.

4.       Mineralization: As decomposition progresses, the organic compounds are further broken down into inorganic forms. This process, known as mineralization, releases nutrients like nitrogen, phosphorus, and carbon in forms that can be readily absorbed by plants. Mineralization contributes to the fertility of soils and enables the recycling of nutrients within ecosystems.

5.       Nutrient Cycling: The nutrients released during decomposition are taken up by plants through their roots, thus entering the food web. The plants utilize these nutrients for growth, and when consumed by herbivores, the nutrients transfer to the higher trophic levels of the ecosystem. Upon the death of organisms, the cycle of decomposition and nutrient recycling begins again.

6.       Decomposition Rates: The rate of decomposition can vary depending on several factors, including temperature, moisture, oxygen availability, nutrient content, and the composition of the organic matter. Warmer and moister environments generally promote faster decomposition rates, while drier or colder conditions slow down the process.

 Decomposition is a vital ecological process that helps maintain the balance and sustainability of ecosystems. It aids in the recycling of nutrients, carbon sequestration, soil formation, and the removal of dead organic matter. It also contributes to the overall diversity and functioning of ecosystems. Understanding decomposition processes is crucial for managing waste, agriculture, forestry, and maintaining healthy ecosystems.