How an ecosystem works: Producers, herbivores, and carnivores
How an ecosystem works: Producers, herbivores, and carnivores
Understanding energy flow in ecosystems.
Encyclopædia Britannica, Inc.
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Encyclopædia Britannica, Inc.Understanding energy flow in ecosystems.
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Encyclopædia Britannica, Inc.In growing plants, roots and leaves play an essential role in transporting the materials the plant needs to survive, such as carbon dioxide, water, and mineral salts.
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© MinuteEarth (A Britannica Publishing Partner)The perfect absorbers of solar radiation are black objects, yet plants, which depend on efficient mechanisms of absorbing solar radiation, are overwhelmingly green. Speculation of why this is so ranges from random chance to the possibility that the radiation-absorbing properties of chlorophyll are adequate to provide for the energy needs of Earth's plants.
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Encyclopædia Britannica, Inc.Experimental evidence of plant respiration.
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Encyclopædia Britannica, Inc.Bryophytes, such as mosses and liverworts, are the most primitive plants.
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Encyclopædia Britannica, Inc.Learn how small changes in the food pyramid can upend the ecosystem.
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Encyclopædia Britannica, Inc.Plants, ranging from the simple liverwort (a bryophyte) to the flowering plants (angiosperms), have evolved structures enabling them to colonize the land of almost any habitat.
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Encyclopædia Britannica, Inc.Overview of how scientists measure biodiversity.
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Encyclopædia Britannica, Inc.The basic components of ecosystems. Most ecosystems contain organisms that are producers (autotrophs), such as plants, that harness energy from the Sun, or consumers (heterotrophs) that feed on producers or other consumers. In a food chain made up of grasses, rabbits, and hawks, the grasses are the producers, and the rabbits and hawks are the consumers.
Transcript
NARRATOR: Hundreds of thousands of different types of creatures live on Earth. Some of these creatures live together and depend on one another for food and shelter. They form a biological community. The physical surroundings--the weather, the soil, and the water in the environment--also play a large role in the life of the community. The living community, and the physical environment that it exists within, is called an ecosystem. There are many types of ecosystems--deserts, marshes, beaches, and even those that are made up of cities and towns. Ecosystems can be as large as a rainforest or as small as a single drop of water. No matter where you live, you're part of one ecosystem or another.
Sunlight usually provides the initial energy needed to sustain an ecosystem. Producers like plants and algae make their own food from sunlight. These producers belong to nearly all ecosystems because they provide food for primary consumers, such as herbivores like deer and zebras. Herbivores then become the food of secondary consumers, such as carnivores like wolves and lions.
Energy is lost when a consumer feeds on a producer or another consumer. For this reason, it takes a great number of plants to supply enough food energy for one herbivore, and many herbivores are needed to support the food energy needed for a single carnivore. This pattern can be explained as a pyramid of feeding levels, or trophic levels, within an ecosystem.
A prairie ecosystem, for example, is covered with grasses, flowers, and other plants. These make up the bottom of the pyramid. Rabbits--which feed on the plants--are not nearly as plentiful. Coyotes--which feed on rabbits--are even fewer still, and thus they form the top of the pyramid in this ecosystem.
Sunlight usually provides the initial energy needed to sustain an ecosystem. Producers like plants and algae make their own food from sunlight. These producers belong to nearly all ecosystems because they provide food for primary consumers, such as herbivores like deer and zebras. Herbivores then become the food of secondary consumers, such as carnivores like wolves and lions.
Energy is lost when a consumer feeds on a producer or another consumer. For this reason, it takes a great number of plants to supply enough food energy for one herbivore, and many herbivores are needed to support the food energy needed for a single carnivore. This pattern can be explained as a pyramid of feeding levels, or trophic levels, within an ecosystem.
A prairie ecosystem, for example, is covered with grasses, flowers, and other plants. These make up the bottom of the pyramid. Rabbits--which feed on the plants--are not nearly as plentiful. Coyotes--which feed on rabbits--are even fewer still, and thus they form the top of the pyramid in this ecosystem.