Energy Transfer in Ecosystems

Study Notes

Energy Transfer in Ecosystems

Roles in Energy Transfer: Different organisms play specific roles in energy transfer within ecosystems. Producers (plants) capture solar energy, primary consumers (herbivores) eat producers, secondary and tertiary consumers (carnivores) eat other animals, and decomposers break down dead organisms, returning nutrients to the ecosystem.
How Organisms Get Energy: All living things need a source of chemical energy to survive. This chemical energy is stored in the bonds of molecules. Organisms obtain this energy from food.
Producers: Producers, also called autotrophs, use energy to make food. Most producers use sunlight to create food through photosynthesis. All green plants, algae, and some bacteria are producers.
Consumers: Consumers eat other organisms for energy and nutrients. Consumers that eat other organisms because they cannot make their own food.
Herbivores: Herbivores eat only plants.
Carnivores: Carnivores eat other animals.
Omnivores: Omnivores eat both plants and animals.
Scavengers: Scavengers are specialized consumers that feed on dead organisms. Examples include vultures and turkey vultures.
Decomposers: Decomposers break down the remains of other organisms, returning nutrients and water to the environment. Examples include fungi and bacteria.
Food Chains: A food chain is the path in which energy is transferred from producers to consumers. Energy flows from the body of the consumed organism to the body of the consumer of that organism. Producers are at the bottom of a food chain, primary consumers who eat plants are next, followed by secondary consumers, then tertiary consumers, and finally decomposers.
Food Webs: Food webs are more complicated than food chains. They show the feeding relationships among all organisms in an ecosystem where multiple, interconnected food chains overlap.
Water Food Web: Water food webs show the feeding relationships in aquatic ecosystems. Sunlight is the initial energy source in water food webs.

Dangerous Competition

Invasive species: Invasive species often compete with native species for energy resources.
Kudzu plant: Kudzu is an invasive plant that outgrows native plants, covering houses and cars.
Zebra mussels and walking catfish: These invasive species are highly successful and may outcompete native species for food.