Why doesn't dead plants and dried leaves emit a foul smell

"During decomposition of animal carcass various chemicals such as ammonia, cadaverine, hydrogen sulfide, and putrescine are produced by the consumption of protiens by anerobic organisms which are charachterised by their foul smell. However in the case of plants, due to a low protien content the extent of production of these foul smelling gases are very small. Therefore decomposition of plants are usually oudourless."

       The reason for emission of foul smell on decomposition of dead animals is due to the release of certain gases during the decomposition process, especially gases such as hydrogen sulfide. As soon as the animal dies the process of decomposition starts, which is effected by enzymes and microorganisms. The process of decomposition takes place primarily by two processes, Autolysis( breakdown of tissue by the action of the body's own enzymes and chemicals) and Putrefaction(decomposition by microorganisms such as bacteria).

       Depending on the composition of the organic matter undergoing decomposition, different types of gases are released. Compared to a dead plant, the animal carcass contains more proteins and water which means the necessary nitrogen and amino acids for microorganisms are provided by the proteins. The various byproducts as a result of putrefaction include ammonia, cadaverine, hydrogen sulfide, and putrescine. As a result the decomposition process is charachterised by the putrid odour of the chemicals and by the discoloration of the body due to degaradation of tissues.

       However compared to animals, plants contain very little protiens and very little or no hydrogen sulphide is released. During decomposition of plants maethane and carbon dioxide are the primary gses released, which are odourless. Moreover the plantss are primarily coposed of cellulose and lignin, which are acted upon by very few microorgasinsms, which ultimately ressults in much delay in decomposition of the plant.

References


[1] http://aggie-horticulture.tamu.edu/earthkind/landscape/dont-bag-it/chapter-1-the-decomposition-process/
[2] http://www.hindu.com/seta/2006/03/09/stories/2006030900381600.htm
[3] http://www.nature.com/scitable/knowledge/library/the-ecology-of-carrion-decomposition-84118259
[4] http://en.wikipedia.org/wiki/Decomposition#Animal_decomposition