Chapter 2: Section 2Energy Flow

Habitat: place where a population of organisms live

Niche: function or role that organisms serve in their habitat

-Tree squirrels eat nuts and seeds and live in nests or dens in trees

-Chipmunks eat nuts and seeds and live in underground burrows

Why can tree squirrels and chipmunks live in the same habitat?

Every living thing needs energy. The source of all this energy is sunlight.

Plants that use the energy from the sun to make their own food through photosynthesis are called producers.

All communities need food from producers for energy.

What are some producers you can think of?

Consumers: organisms that eat other organisms for food

Different types of consumers

Herbivores: _animals that eat only plants

Carnivores: _animals that eat only other animals

Omnivores: animals that eat both animals and plants

Scavengers: animals that eat animals they find already dead

What are humans? Explain your answer.

Decomposers: Organisms that get energy by breaking down the remains of dead organisms

Decomposers are nature’s recyclers

They extract the last bit of energy from dead organisms and break them down into simpler materials like water, carbon dioxide, and nutrients like oxygen and nitrogen

What are some decomposers?

Energy is transferred through a community by food chains.

Look at Figure 2-14 on p.45 of the meadow community food chain.

How is energy moving through that chain?

Each organism in a food chain uses some energy to stay alive and stores some energy in its tissues.

How might energy be lost from the food chain?

Look back at Figure 2-14. Are grasshoppers the only animal in a meadow that is going to eat grass? Is grass going to be the only plant/producer that is in the meadow?

Many food chains exist within a community. Take a look at Figure 2-15. What is the producer here? What are the consumers?

Consumers usually eat more than one type of food and they themselves might be eaten by another consumer.

This causes food chains to be connected to make up a food web.

Let’s see what that looks like

Why is a food web a better representation of the relationships between producers and consumers than a food chain?

Community must have many more producers than consumers because producers provide the energy necessary for both themselves and the consumers.

As you get further away from the producers you lose more and more energy. Each organism only stores about 10% of the energy it consumes or makes.

This 10% is the only energy that the animal who eats the organism will receive. This means that for every step in the food chain, 90% of the energy is lost in each step.

Figure from Chap 18 Sect 2 of New Life Science Textbook

There are 12,000 units of the sun’s energy available to grass at the base of the energy pyramid. Grass stores 10% of the available energy in its tissues, so that becomes available to the next consumer a rabbit.

The rabbit, a consumer of grass, stores 10% of the energy that was stored in the grass.

A coyote, a consumer of rabbits, stores 10 percent of the energy that was stored in the rabbit.

Calculate the unites of food energy store in the grass, the rabbit, and the coyote.

Grass= 0.1 x 12,000= 1,200 units of energy stored in the grass

Rabbit= 0.1 x 1,200= 120 units of energy stored in the rabbit

Coyote= 0.1 x 120= 12 units of energy stored in the coyote

Is it possible for an inverted energy pyramid to exist? Why or why not?