Nutrient Recycling
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The sun supplies a virtually limitless supply of energy to the ecosystems. However, this is not the situation for Nutrients, they must be constantly recycled in nature for the continuity of life. There are 2 main nutrient cycles;
- Carbon Cycle
- Nitrogen Cycle
[edit] The Carbon Cycle
Carbon is a basic element of all living things. All organisms produce Co2 gas as a waste product of respiration. Plants absorb Co2 from the air for use in photosynthesis. This produces carbohydrate that can be converted to other foods required by the plant. The diagram below shows a summary of changes in the forms of carbon that occur in nature;
[edit] The Nitrogen Cycle
This cycle describes the changes in the forms of nitrogen that occur in nature. The cycle is essental for the survival of organisms. Bacteria play a large role in this cycle
Nitrogen (N2) is a vital component of amino acids and proteins. Enzymes (protein) control metabolism in all living organisms. 80% approx of the atmosphere is made up of N2 gas. In this form it cannot be used by plants or animals. Bacteria in the nitrogen cycle convert N2 gas to Nitrates (NO3-). Nitrates are then absorbed by the roots of the plants & used to make plant protein. Animals consume the plants, converting them to animal protein.
[edit] Nitrogen Fixation
is the term given to the conversion of N2 to NO3- . It is brought about by 2 different types of bacteria. 1 of the types of bacteria is found on the Nodules of the roots of Legumes. It fixes N2 for the plant, the plant in return supplies sugars to the bacteria.
This relationship between 2 different organisms living together is defined as Symbiosis. The association between the 2 is beneficial to both so it is known as Mutualism.
