The diagram illustrates the important role that microbes i.e. algae, cyanobacteria and the decomposers, play as primary producers and in the cycling of nutrients.
Step 1: Photosynthesis
Step 2: Primary producers
Step 3: Aerobic respiration
Step 4: Decomposition
Green algae and cyanobacteria are found at the beginning of the food chain. They are known as primary producers because they make their own food.
Where has that carbon atom been? The carbon cycle is a complex cyclical process through which all of the carbon atoms in existence rotate.
Similar to the carbon cycle the nitrogen cycle is the process by which nitrogen in all its forms, cycles to the environment.