Nature
Pyramid

3rd grade fall unit

revised August 3, 2007

Vocabulary

Organism - any living thing

Adaptation - something that an animal has or does that helps it to live in its habitat

Decomposer - organism that decays or rots plants and animals in place, returning the nutrients to the soil (fungus, mold, bacteria, etc.). For our purposes, also will include "shredders" which aren't truly decomposers by assist the decomposition process (worm, pill bug, millipede, sow bug, some other creepy crawly creatures) See another web page of River Bend's for more on decomposers!

Producer - organism capable of making its own food from sunlight, water, and nutrients and chlorophyll (green plants)

Primary Consumer - organism which gets its food from plants (rabbit, squirrel, deer, mouse, honey bee, aphid, grasshopper, tadpole, duck, black bear, mosquito, humpback whale, other animals at times).
Secondary Consumer - organism which gets its food mainly by eating primary consumers, but can also be prey itself. (weasel, shrew, mole, merganser, snake, spider, frog, most fish, other animals at times).

Top Level Consumer - organism which gets its food mainly by eating other consumers, but rarely becomes prey itself. (hawk, wolf, shark, fox, dragonfly, orca, human).

Carnivore - organism that consumes meat (weasel, wolf, walleye, owl)

Herbivore - organism that consumes plants (deer, rabbits, woodchuck, duck)

Omnivore - organism that consumes both meat and plants (skunk, raccoon, human)

What is a plant?

A plant is an organism that is almost always rooted to one place. It makes its own food and it "breathes" in carbon dioxide and "breathes" out oxygen. There are many different groups of plants. Some examples are trees, flowers, or grasses.

What is an animal?

An animal is able to move around on its own power. It gets its food from other living or once-living things. It breathes in oxygen and breathes out carbon dioxide. There are many different types of animals, but they can be divided into two large groups:

• Warm blooded animals, whose inside body temperature stays the same all the time. With proper homes and food, they can still function in cold winter temperatures. We are warm-blooded animals.
• Cold-blooded animals that do not have a steady inside body temperature. These animals have an inside body temperature that matches the temperature outside. Therefore, being unable to survive winter temperatures, they must migrate or hibernate. Snakes, frogs, and fish are examples of cold-blooded animals.

How can we tell the different animals apart?

Each group of animals have "things" that are different from other groups. We call these "things" characteristics or adaptations. By comparing these characteristics, we can put everything into groups.

Within each group we look for the special habits different animals have. Some of the habits we look at include:

• What does the animal eat?
  • If the animal eats other animals (meat), it is called a carnivore.
  • If the animal eats plants, it is called a herbivore.
  • If the animal eats anything, it is called an omnivore.
• When does the animals eat?
  • Does it eat during the day?
  • Does it eat during the night?
  • Does it eat at sunrise and sunset only?
• Where does the animal live?
• What are some of the specializations of the the body parts?
• When does the animal have babies and how to they eat?
• What does the animal look like?
  • size
  • color
  • exterior covering i.e. furs, feathers, scales

How can we tell different plants apart?

Just as animals are divided into groups by their different characteristics, so are plants. The special characteristics we look at include:

• When does it replace its leaves?
  • If a plant does lose its leaves, it is called a deciduous plant.
  • If a plant doesn't lose its leaves, it is called a coniferous plant.
• What is the size of the plant?
• When does the plant bloom and release its seed?
• Does it grow a woody stem or a green one?
• Does it have many leaves, stems or flowers on each individual plant, or just one?
• What type of habitat does it prefer?
  • wetlands
  • forest
  • prairie
  • desert
  • oceans
  • mountains

Why are plants and animals important?

Every type of plant and animal is a critical building block of the nature pyramid. Listed below are the major groups that are important to recognize.

Why do plants and animals "eat?"

All forms of life burn up energy throughout their existence and this energy must be replaced, much like adding wood to a campfire. That energy comes from the food we eat, as well as other nutrients and compounds to replenish those we use up in our activities and lose in our waste.

Green plants, as producers, make their own food out of water, air, sunlight, nutrients, and a special chemical called chlorophyll that only plants have and makes them green. They make sugar, which they use up to stay alive and is also passed on to whatever animal eats them.

The Nature Pyramid

Producers (green plants) are the only things on Earth that can make their own food. Every other living thing depends on this food, either by directly eating plants or by eating other animals that ate the plants, and so on.

(Click here to download the above image in .jpg form)

Plants and animals use other plants and animals as food or shelter in order to survive. If a plant or animal suddenly disappeared, other things that needed it to survive might also die. So plants and animals are important to each other. Why are non-living things needed?

Non-living things in the nature pyramid:
A nature pyramid also contains some non-living things that are needed to help the living things survive. Those non-living things are:

• air
• water
• rocks and soil (although most soil has organic material)
• sunlight

Discussion questions:

• What would happen if there weren't any decomposers?
• Do plants really need animals?
• What would happen if there were more animals than plants?

What do we need to remember when we visit River Bend?

1. Be quiet.
2. Listen to your leader.
3. Raise your hand if you have something to say.
4. Do not pick anything unless given permission.
5. Stay with your group and on the trail.
6. Be respectful of nature - and of each other!

Some suggested pre- or post-visit activities

Send us your ideas here!

• After completing three pyramids at River Bend, create the fourth side to the pyramid, using either an exotic or fictional habitat, to demonstrate each student's understanding.

Interesting links

The following links contain some interesting information food chains/webs and the energy pyramid: Send us your ideas (and broken links) here!

Watch a Food Chain movie and play a game along the way!
http://www.brainpop.com/search/?keyword=food+chain

Here's a colorful page on food chains
http://www.planetpals.com/foodchain.html

Here's a game that you might be interested in buying-
http://www.cajungames.com/foodchain/

Fun with fungi http://namyco.org/educ/k-12.htm

(c) River Bend Nature Center
Faribault MN USA
www.rbnc.org
rbncinfo@rbnc.org
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