Energy sources
The primary source of energy for organisms and the ecosystems of which they belong to is sun. Plants and algae, use energy that comes from sunlight to make food energy by combining carbon dioxide and water to form organic matter, these are called as producers.
Energy is generally transferred between organisms from producers to consumers in food webs. This energy is used to carry out complex tasks by organisms. In a food chain system, most of the chemical energy is converted to other forms such as heat at every stage, and does not remain within the ecosystem.
The major roles of energy within an ecosystem are producer, consumer, and decomposer. Photosynthesis is a process through which organisms make their own food by using the sun's energy to turn water and carbon dioxide into food. Producers are the basic source of all the food available in an ecosystem.