TROPHIC LEVELS
Please read this entire page and then return to the home page. In the scientific field of ecology there are four categories of organisms. They are defined by the type of activities they perform within an ecosystem. These four categories are defined as :
PRODUCER : an organism that captures energy from the sun and converts it into chemical energy. An example is any plant (rose, tomato, tree). In fact all plants are producers
CONSUMER : an organism that eats another organism. The organism being eaten can be from any of these four categories. An example is a snake, tiger, or parasite.
SCAVENGER : an organism that eats other organisms that are dead when they find them. An example is a vulture hyena, and sea gulls.
DECOMPOSER : an organism that breaks down living and dead tissues into a chemical form that can be taken up by other organisms, especially plants. Examples are fungi and bacteria.
Producer Trophic Level
This level is defined as all organisms who capture energy from the sun and convert it to chemical energy. All plants, through the process of photosynthesis, capture solar energy from the sun and convert it to chemical energy in the form of food. Actually the energy is stored in the chemical bonds of the sugars, starches, and proteins within different structures within the plants. All plants are producers.
Consumer Trophic Levels
This level is defined as one organism eating another organism. Consumers are organisms that can not capture energy directly from the sun. These organisms must eat something else and capture the energy from that food. The trophic levels are numbered depending on what is being eaten and what that food source has been feeding on. When an animal such as a mouse eats a producer such as a rice plant, the animal is said to be feeding on the first trophic level and the mouse is a first order consumer. When the cobra eats the mouse, the cobra is eating a first level consumer. This makes the cobra a second level consumer in this example.
When energy passes from one trophic level to the next, 90 % of the energy in the organism being eaten is lost (to heat, maintaining the eating organism, and to movement of the eating organism) and 10 % of the energy is available to the next trophic level. Because only 10 % of energy moves from one level to the next, most food webs will only go as high as the 4th or 5th consumer level.
Scavengers
Scavengers are a special kind of consumer in that they eat all types of producers and consumers and therefore eat on all trophic levels. Scavengers are special in that they recycle the energy from the flesh of dead organisms directly back into the food web for other consumers to use.
Decomposers
These organisms are defined by their function of taking dead producers, consumers, or scavengers or even other dead decomposers and breaking their bodies down into organic forms that can then be taken up by plants and formed into new producers. Without decomposers, all organic matter would be tied up in dead organisms and there would be no more organic molecules available for new organisms to use to grow. The earth would be cluttered with dead bodies everywhere. Dead bodies stink because of decomposers so the good news is without decomposers the dead bodies would not stink the place up.
If you think you understand the difference between trophic levels, producers, consumers, scavengers, and decomposers, return to the home page by clicking on the tiger below and begin your research.
