Question

1. Describe three processes that are important for decomposition of leaves in a stream. Explain which organisms are important for each of the processes.

Answer 1

Answer. Leaves form the organic matter part of the environment. Organic matters are generally decomposed by the environmental microbes present in soil or water or air. These include bacterias, fungi, etc. These organisms breakdown the organic components by decomposition to form carbon dioxide and other nutrients. As time goes by, the leaves due to various environmental factors age out and lose their color and leach out. These leaves then fall on the ground wherein the microbial community feeds on it. After decomposition, the nutrients obtained are mixed within the soil for its fertility.

Apart from the microbial decomposition, there are physical factors that might lead to the decomposition of the leaves. Also, some invertebrates are also responsible for the decomposition of leaves. These invertebrates act like "shredders" and belong to the aquatic community. These invertebrates include leeches, mites, worms, etc. Bacterias that decompose leaves are Bacillus, Clostridium, Pseudomonas, Streptomyces, etc. While fungi include Aspergillus, Penicillium, Rhizopus, Trichoderma.