|MadSci Network: Environment & Ecology|
This question is basically asking whether or not everything decomposes completely. The answer to this question is "It depends!" If everything decomposed completely we would have no fossil fuels, among other things. On the other hand if nothing decomposed all the carbon and many other nutrients would be locked up in dead organic matter and life would cease to exist! It is possible to find buried logs that are thousands of years old, and soild organic matter has been dated to tens of thousands of years. Using this information, youmay be able to approach the answer to your question. A recent article in the journal Science may shed light on this. Carbon Sequestration in Soils, by William H. Schlesinger Science 1999 June 25; 284: 2095
Try the links in the MadSci Library for more information on Environment & Ecology.