A pyramid representing trends in food consumption, with the lowest level (primary producers)
having the greatest total biomass, and the higher consumer levels having successively less total
The concept of a pyramid of
consumers in an
helps to understand how an organism fits into a community
as a whole.
Trophic structure is the pattern of movement of energy and matter through an ecosystem.
It is the result of compressing a community food web into a series of trophic levels. Shown here as a food pyramid,
we can see how energy moves upward through the system.
Typical Desert Food Pyramid
4th Trophic Level:
3rd Trophic Level:
These are high level consumers, carnivores that will eat other carnivores.
2nd Trophic Level:
Small Carnivores -
are the secondary consumers. They occupy the third trophic level. Again we see cold-blooded animals,
tarantualas. Only about
2 Kilocalories per square meter per year are
stored in their bodies. In the harsher desert environments, they are the top predators.
1st Trophic Level:
These animals are usually small and eat little. Many are insects, or reptiles, who are cold blooded and who use
less energy to maintain their bodies than mammals and birds do. As food for predators, they provide about 20
Kilocalories per square meter per year for predators.
Including: Ants and other
rats and mice,
the largest of which are the
These are plants that make food through photosynthesis. Limited by the availability of water, they produce fewer than
200 Kilocalories of food for the animals for each square meter each year.
Desert Food Webs
The interconnected feeding relationships in an ecosystem. These relationships can be complex; some organisms