Alpine Tundra
A basic food web/chain.

Food Chain


 Tertiary Consumers and eat the Secondary consumers and so on and so forth.

Secondary Consumers come in and eat the Primary consumers.

Primary Consumers which eat the producers.


First is the Primary Producer which takes in sunlight and converts it to energy.

Energy flow is the amount of energy that moves throughout a food chain.  The largest energy for an ecosystem is the sun.

Energy that is not used in an ecosystem is usually turned into heat. Energy and nutrients are passed through the food chain, when one organism eats another organism. Any energy left in a dead animal is consumed by decomposers. The low amount of energy that transfers between trophic levels makes decomposers more important than producers because of the energy flow. Decomposers process large amounts of organic material and put nutrients to the ecosystem in inorganic formula, which is then taken up again by primary producers. Energy is not recycled during decomposition, but is released.Most of the food we eat comes from simple food chains. The food chains begin with the producers, organisms such as autotrophs (for example green plants that make their own food). Through photosynthesis producers convert solar energy to chemical energy. Of all the energy a plant gets from the sun it only converts 3 per cent to chemical energy. The amount of chemical energy changes depending on the species of the plant and where it is located. Plants are eaten by many organisms that can only obtain their energy by feeding on other organisms. These are called heterotrophs. They include consumers of any organism, in any way: plants, animals, microbes, even dead tissue. Heterotrophs also are called consumers. The herbivores feed on the autotrophs and change the energy from the plant into energy that they can use. Carnivores obviously feed off the herbivores and then carnivores finally feed off carnivores. In each case, energy is passed on from one Trophic level to the next trophic level and each time some energy is gone as heat into the ecosystem. This is because that organism must use some energy that they have from other organisms so they can survive. The top consumers of a food chain will be the organism with the less amount of energy. On average about 10 per cent of energy production at one trophic level is passed on to the next level.

Rp =Respiration by Plants.

Rh = Respiration by Heterotrophs.

Rd = Respiration by Decomposers.

Equation of Photosynthesis

A video the describes how energy flows through an ecosystem: