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The slow rate of decomposition of fallen logs in nature is due to their:
A
anaerobic environment around them
B
low cellulose content
C
low moisture content
D
poor nitrogen content
Detailed Solution
Decomposition is carried out by the enzymes of bacteria and fungi, and its rate is controlled by the chemical composition of the detritus and by climatic factors, mainly temperature and soil moisture.
Decomposer microbes need water for their growth and for their extracellular enzymes to act. A warm and moist environment favours decomposition, whereas dryness inhibits it.
Fallen logs are made of dry, dead wood with a low moisture content, so microbial activity in them is slow and they decompose slowly. This is the answer given in the answer key.
The surroundings of a fallen log are aerobic, not anaerobic, and wood is rich in cellulose, not low in it.
The chemical nature of wood also contributes: the decomposition rate is slower if the detritus is rich in lignin and chitin, and quicker if it is rich in nitrogen and water-soluble substances like sugars. Wood is rich in lignin and poor in nitrogen, so some books give poor nitrogen content as the answer to this question.
Decomposer microbes need water for their growth and for their extracellular enzymes to act. A warm and moist environment favours decomposition, whereas dryness inhibits it.
Fallen logs are made of dry, dead wood with a low moisture content, so microbial activity in them is slow and they decompose slowly. This is the answer given in the answer key.
The surroundings of a fallen log are aerobic, not anaerobic, and wood is rich in cellulose, not low in it.
The chemical nature of wood also contributes: the decomposition rate is slower if the detritus is rich in lignin and chitin, and quicker if it is rich in nitrogen and water-soluble substances like sugars. Wood is rich in lignin and poor in nitrogen, so some books give poor nitrogen content as the answer to this question.