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Wildlife -
Food Chain
Food Pyramid
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
biomass.
The concept of a pyramid of
consumers in an
ecosystem
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:
Tertiary Consumers
Carnivores -
These are high level consumers, carnivores that will eat other carnivores.
3rd Trophic Level:
Secondary Consumers
Small Carnivores -
The
predators
are the secondary consumers. They occupy the third trophic level. Again we see cold-blooded animals,
such as
snakes,
insect-eating
lizards, and
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.
2nd Trophic Level:
Primary Consumers
Herbivores
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
insects,
rats and mice,
some
reptiles
the largest of which are the
tortoise and
chuckwalla.
1st Trophic Level:
Primary Producers
Plants -
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.
Including:
Trees,
shrubs,
cactus,
wildflowers,
grasses
Desert Food Webs
The interconnected feeding relationships in an ecosystem. These relationships can be complex; some organisms
may ...
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