Ecosystem Energy:

Organisms can be either producers or consumers in terms of energy flow through an ecosystem. Producers convert energy from the environment into carbon bonds, such as those found in the sugar glucose. Plants are the most obvious examples of producers; plants take energy from sunlight and use it to convert carbon dioxide into glucose (or other sugars). Algae and cyanobacteria are also photo- synthetic producers, like plants.

Other producers include bacteria living around deep-sea vents. These bacteria take energy from chemicals coming from the Earth’s interior and use it to make sugars. Other bacteria living deep under­ground can also produce sugars from such inorganic sources. Another word for producers is autotrophs.

Consumers get their energy from the carbon bonds made by the producers. Another word for a consumer is a heterotroph. A trophic level refers to the organisms position in the food chain. Autotrophs are at the base. Organisms that eat autotrophs are called herbivores or primary consumers. An organism that eats herbivores is a carnivore and a secondary consumer. A carnivore which eats a carnivore which eats a herbivore is a terti­ary consumer, and so on.
It is important to note that many animals do not specialize in their diets. Omnivores (such as humans) eat both animals and plants. Further, except for some specialists, most carnivores don’t discriminate between herbivorous and carnivorous bugs in their diet. If it’s the right size, and moving at the right distance, chances are the frog will eat it.

# The ultimate source of energy (for most ecosystems) is the sun. The ultimate fate of energy in ecosystems is for it to be lost as heat. Energy and nutrients are passed from organism to organism through the food chain as one organism eats another. Decomposers remove the last energy from the remains of organisms. Inorganic nutrients are cycled, energy is not.