Ecology

Rainforest Ecology and Food Web

A Simple Dictionary Of Common Terms

Autotroph

An organism capable of capturing light and making its own food (photosynthesis).

Carnivore

An organism that feeds on other consumers (meat eaters).

Commensalism

A symbiotic relationship where one species benefits and the other neither benefits or is harmed.

Community

Populations of different organisms that live together.

Consumer

Organisms that cannot make their own food.

Decomposer

An organism that breaks down organic matter in the bodies of other organisms.

Ecology

The study of the relationship between organisms and their environment.

Ecosystem

A major interacting system which involves both organisms and their non-living environment.

Food Chain

A part of a food web which focuses on an individual sequence of who eats whom.

Food Web

A diagram or picture of who eats whom in an ecosystem.

Habitat

The place where an organism lives.

Herbivore

An organism that eats only producers (green plants).

Heterotroph

An organism that depends on autotrophs for its food.

Mutualism

A symbiotic relationship where both species benefit.

Niche

The role of an organism in its environment.

Omnivore

An organism that eats both producers and consumers (green plants and meat).

Parasitism

A symbiotic relationship where one species benefits and the other is harmed.

Population

Individuals of the same species living together in the same environment.

Predator

An animal that hunts and eats other animals.

Prey

An animal who is hunted and eaten by another animal.

Producer

An organism capable of making its own food (plants, algae, and some bacteria).

Organism

A living creature, with one cell or many cells.

Symbiotic Relationship

Two different kinds of organisms living in close contact with each other.

Check Out These Sites

Ken's Bio-Web References

Environmental Biology - Ecosystems

Symbiotic Relationships In The Rainforest

Tropical Ecosystems Of Costa Rica And Panama

Mutualism - The Cape buffalo benefits by having the birds (Red-billed oxpeckers) groom and clean him. The birds benefit by having a supply of insects. Photo © Bob Krist/CORBIS, courtesy Ron Kalasinskas

Commensalism - Many birds build their nests in trees. The birds benefit by having a place to bring up their young. The tree also provides the birds with safety from many predators. In most cases the tree does not benefit nor is it harmed. Above, a sunbittern feeds a frog to its young. Photo © Michael & Patricia Fogden/CORBIS, courtesy Ron Kalasinskas (Additional sunbittern information at Sunbittern )

Tick

Parasitism - A tick is attached to this rainforest toad. The tick benefits by having a supply of blood. The toad is harmed as the loss of blood will eventually weaken it and possibly result in its death. Photo © W. Perry Conway/CORBIS, courtesy Ron Kalasinskas

Predator Prey

Predator/Prey - A predator is an animal that hunts and feeds upon other animals. The animal that gets hunted or eaten is called its prey. Life in the rainforest is filled with predator/prey relationships. Above, a neotropical rain frog is swallowed by a rear-fanged snake. Predation is a fact of life in the rainforest. It helps keep the food chain in balance. Photo © Michael & Patricia Fogden/CORBIS, courtesy Ron Kalasinskas

A Simple Amazon Rainforest Food Web

Note: Because of the number of organisms and complexity, no single drawing can possibly show a complete rainforest food web. The above web was created only to illustrate "energy flow" in an ecosystem. I will try to improve it from time to time.

Above pyramid for illustration purposes only. Not drawn to scale.

Most ecosystems have primary producers, primary consumers, secondary consumers, and decomposers. These are called trophic levels.

Primary producers (green plants) take the sun's energy and make their own food.

Primary consumers are called herbivores (plant eaters). They feed on the primary producers.

Secondary consumers are carnivores (meat eaters) and they eat the primary consumers.

Decomposers break down organic matter and recycle it back to the primary consumers. The King Vulture is a decomposer as it feeds on dead animals. Fungi and bacteria are decomposers.

Food pyramids show relationships between the above trophic levels.

Three main types of food pyramids are "pyramid of biomass", "pyramid of energy", and "pyramid of numbers".

A pyramid of numbers would show the actual total number of organisms at each trophic level for a given area. The greatest number of organisms would be at the primary producer level, decreasing greatly as you move up the pyramid.

A pyramid of energy would show the energy available at each trophic level for a given area. As you move up the pyramid the amount of energy available is drastically reduced. Much energy is lost as heat and through respiration.

A pyramid of biomass (weight) would show the actual total weight of all organisms in each trophic level for a given area. Primary producers would, by far, have the greatest biomass. As you move up the pyramid each trophic level has much less biomass than the level below it.

Ecosystems can be very complicated, and while food pyramids are not perfect, they do give a nice pictorial representation of trophic relationships.

A Very Simple Food Chain


Autotroph	An organism capable of capturing light and making its own food (photosynthesis).
Carnivore	An organism that feeds on other consumers (meat eaters).
Commensalism	A symbiotic relationship where one species benefits and the other neither benefits or is harmed.
Community	Populations of different organisms that live together.
Consumer	Organisms that cannot make their own food.
Decomposer	An organism that breaks down organic matter in the bodies of other organisms.
Ecology	The study of the relationship between organisms and their environment.
Ecosystem	A major interacting system which involves both organisms and their non-living environment.
Food Chain	A part of a food web which focuses on an individual sequence of who eats whom.
Food Web	A diagram or picture of who eats whom in an ecosystem.
Habitat	The place where an organism lives.
Herbivore	An organism that eats only producers (green plants).
Heterotroph	An organism that depends on autotrophs for its food.
Mutualism	A symbiotic relationship where both species benefit.
Niche	The role of an organism in its environment.
Omnivore	An organism that eats both producers and consumers (green plants and meat).
Parasitism	A symbiotic relationship where one species benefits and the other is harmed.
Population	Individuals of the same species living together in the same environment.
Predator	An animal that hunts and eats other animals.
Prey	An animal who is hunted and eaten by another animal.
Producer	An organism capable of making its own food (plants, algae, and some bacteria).
Organism	A living creature, with one cell or many cells.
Symbiotic Relationship	Two different kinds of organisms living in close contact with each other.