energy pyramid
definition
An energy pyramid is the model of how energy flows in the ecosystem. It is divided into different trophic levels. The first trophic level are the producers. They are known as autotrophs, who make their own energy (such as glucose) and are not dependent on other organisms for nutrition. As for the heterotrophs, or consumers, they depend on other organisms as their food source. The second trophic level is composed of the heterotrophs. The third trophic level is made up of consumers who eat the heterotrophs (they share a predator/prey relationship). They are called the secondary consumers. The consumers in the fourth trophic level in our ecosystem are the tertiary consumers, which are animals who eat the secondary consumers. Lastly, the decomposers finish off the web, because they eat the remains of any decayed organisms. They are called the detritus. The producers transfer 10% of their energy to the second trophic level, which are made up of primary consumers. Each trophic level transfer 10% of their total energy to the proceeding level and keep 90% for themselves. Autotrophs use energy for respiration, growth, and reproduction. Heterotrophs use their energy for movement on top of respiration, growth, and reproduction. Less and less energy become available as it flows up the trophic levels of the pyramid. As a result, having more consumers is disadvantageous because less energy will become available.
explanation
In our food web, the first trophic level consists of grass, the second trophic level is the bird (the bird eats seeds from the grass), the third trophic level is an owl, and the fourth trophic level consists of a hawk. The grass uses up 90% of their energy, and so, when the bird eats the grass, it only gains 10% of the energy. This continues on to the top of the pyramid.