Energy Flow in an Ecosystem 5.02 Analyze the flow of energy and the cycling of matter in the ecosystem.

Why do living things need energy? All living things need energy in order to maintain homeostasis.

What is the major source of energy in our biosphere?

What are the two methods organisms use to obtain energy? Organisms use one of two methods in order to obtain their energy and nutrients. They can either be….. Autotrophs Heterotrophs

What is an autotroph? An autotroph is an organism that makes its own food. It gets the energy it needs to do this from the sun. Most autotrophs carry out photosynthesis.

What is an autotroph? Autotrophs are also known as producers. Plants are an example of autotrophs.

What is a heterotroph? A heterotroph is an organism that must consume another organism for an energy source. Heterotrophs can not make their own food.

What is a heterotroph? Heterotrophs are also called consumers. All living organisms EXCEPT plants are consumers.

Types of Heterotrophs There are five different types of heterotrophs. Herbivore Carnivore Omnivore Scavenger Decomposer

Herbivores Eat plants Also known as primary consumers.

Carnivores Eat other animals

Omnivore Eat plants and animals

Scavengers Eat dead stuff  the “leftovers”

Decomposers Biodegrade or break things down.

Pyramid of Energy Scavengers and Decomposers 3rd Heterotroph Carnivore eats carnivore 4th Trophic Level 2nd Heterotroph Carnivore eats herbivore 3rd Trophic Level 1st Heterotroph Herbivore eats plants 2nd Trophic Level Autotroph- Plant Producers 1st Trophic Level

The Pyramid of Energy Trophic Level = Energy Level Only 10% of energy goes to the next level. The rest of the energy is either used up or lost as heat.

The Pyramid of Energy As you move up the pyramid, energy is lost so the amount of energy available decreases.

Food Chains/Food Webs Producers Consumers Decomposers A food chain shows how an animal gets its food. Always starts with plants and ends with an animal. There are 3 different roles in the food chain: Producers Consumers Decomposers

Producers Autotrophs (make their own food). Plants are producers They get their energy directly from the sun Contain the most energy.

Consumers Heterotrophs: (Cannot make their own food). Herbivores: Primary consumers, only eat plants Carnivores: Secondary consumers, eat herbivores. Tertiary consumers, eat other carnivores Omnivores: Eat both plants & animals

Decomposers Feed on dead/decaying matter and break it down. Ex. Bacteria & Fungi

Energy Flow in a Food Web Producers contain the most energy because they get their energy directly from the sun. The primary consumer (plant eater) only gets a small portion of the energy contained in the plant, because much of the energy was used by the plant for its life processes. Tertiary consumers get the very least amount of energy from their food.

Therefore… The higher up on the food chain, the population should be smaller. At the bottom of the food chain, the population should be larger. In other words, a large number of living things at the base is required to support a few at the top ... many herbivores are needed to support a few carnivores