8. Ecosystem Organization

Ecosystem Pyramid student workEcosystem Pyramid student work The study of ecology has many layers, ranging from the individual organism, to the population, to the ecosystem, to the planet. It is important for students to know the levels within this hierarchy and to recognize which level they are focusing on at any one time. For the purposes of this activity, students will learn about the different levels (organism, population, community, ecosystem, biome, and biosphere) by choosing an organism and the illustrating a pyramid about that organism. The result is a colorful display of organizational pyramids.

Can define and explain the relationships among: individual organisms, populations, communities, ecosystems, biomes, and the biosphere.
Can explain some of the reasons why different regions of the globe have different climates, and thus support different biomes.
Can describe the characteristics of familiar biomes: tundra, desert, prairie (grassland), deciduous forest, tropical rain forest, ocean.

Deciduous forest
Tropical rain forest

8ecosystem_org.doc50 KB
ecosystem_org_teacher.doc29 KB
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8. Ecosystem Organization - Logistics

45-55 minutes



  1. Copies of blank Ecosystem Organization Pyramid
  2. Overhead copy of the Ecosystem Organization Teacher Pyramid
  3. Colored pencils
  4. Optional: photographs or posters of various biomes (I recommend cutting out magazine photos from National Geographic or Smithsonian Magazines or getting old landscape photography calendars when they go on sale in March or April.)


8. Ecosystem Organization - Background

Teacher Background
In order to study ecology, scientists need to see how organisms are related to one another and also to the environment in which they live. To do this, it is useful to think about a hierarchy of ecosystem organization ranging from the individual organism to the biosphere.

To begin with, consider a single organism, the individual. An “organism” is any living thing, whether it is a human being, a germ, a rose bush, or a panda bear.

A group of organisms of the same kind is a population. A “population” can be defined as a group of interbreeding organisms living in the same area. You might imagine a human population such as the population of the city in which you live or the population of a certain country. The humans within that population live in the same area and can interbreed and have babies. Similarly, a population of dandelions might all live in the same field and share pollen or a population of dolphins might all live in the same body of water and have babies.

A community is the next largest level of organization. A “community” includes all the organisms, sometimes hundreds of different types, in a given area. Several different populations are usually found in a community. The populations within a community are interdependent because of the food webs that bind them together. Communities can vary greatly in size. For instance, you could consider the community within a certain forest or you could think about a community in a garden. In MyScienceBox, students study microhabitats and look at a community within a single square meter. Communities can be even smaller such as the community that lives on and inside a single human being. On our skin are various molds, yeasts, and bacteria. In our hair we may have lice. In our intestines are E. coli and other bacteria. Many microscopic critters live in our mouth. Thus, there is a community of organisms living in and on your body!

Until now, we have only considered the living things in an area. The next level of the organization, an ecosystem, begins to include the nonliving parts as well. An “ecosystem” includes all organisms in a defined area and their nonliving environment. When you study an ecosystem, you look at how the nonliving and living parts affect one other. When you study a community, you only look at how the living things affect each other. Like a community, an ecosystem can be large or small. The Earth is the largest of all ecosystems which is called the “biosphere”.

The Earth ecosystem can be divided into several major biomes. A “biome” is one of several major types of ecosystems found on the planet. Each biome is characterized by a particular type of vegetation. Biomes generally encompass large geographical areas and are not sharply delineated (one will blend into another). You probably are already familiar with the major biomes already: desert, rainforest, grassland, tundra, coniferous forest, deciduous forest, and mountain. Some include the ocean as a non-terrestrial biome. One important point is that even though a biome like a rainforest will be similar anywhere in the world – all will have large trees, vines, many bird and animal species, etc. – the exact type of species of tree and the exact type of vine will vary from rainforest to rainforest. Thus in one kind of biome, different organisms will occupy the same niche. These organisms tend to be similar in form but often come from very different evolutionary backgrounds (for instance, consider the numbat, an Australian marsupial anteater, and other mammalian anteaters around the world including the giant anteater and the armadillo).

Student Prerequisites

Some understanding of food webs is useful but not required.

8. Ecosystem Organization - Getting Ready

Getting Ready

  1. Make copies of the Ecosystem Organization Pyramid
  2. Set out colored pencils
  3. Collect and display photographs or posters of various biomes

8. Ecosystem Organization - Lesson Plan

Lesson Plan

  1. I began this lesson with a visualization exercise. When all students are seated, instruct them to close their eyes and imagine an animal, anything they want as long as it lives in the wild (not a dog, cat, horse or other domesticated animal) and they know something about it.
  2. First have them think about their animal alone as an individual. What does it look like? How does it move?
  3. Then imagine this animal interacting with others of its kind. Does your animal live alone or in a group? How does it take care of its young? How does it interact with other adults of its species?
  4. Next think of other types of living things your animal might interact with. What does it eat? What eats it? Does it depend on grasses or trees for shelter or making a nest? Does it compete with other types of animals for food?
  5. Next think of the non-living things that your animal interacts with. Where does it live? Where does it find water? What type of soil does it live on? What is the weather like where it lives?
  6. Finally, think about your organism in relationship to the whole planet Earth. Imagine a picture of the Earth from space. Where on the planet does your animal live? How does its life affect the lives around it? Hoe does its life affect you?
  7. Have the students open their eyes. Tell them that in their imaginations they zoomed out from one individual organism to the whole planet. Ecologists who study organisms and their environment think about organisms and their environment at different levels of “zoom”. Some study at small groups of the same kind of animal – like Jane Goodall who studies chimpanzees in Africa. Some study a whole type of ecosystem, like rainforests or deserts and all the creatures that live within it. Some study the whole planet. Today we will be thinking of the words ecologists use to describe the various levels of “zoom” and will be drawing a picture to illustrate these different levels.
  8. Give students the blank student copies of the Ecosystem Organization Pyramid while you put the Teacher version on the overhead. (If you are short on time, you can give students the Teacher version directly and not have them copy the words and definitions.) Discuss each of the words that defines each level of the organization and have students copy the words and definitions onto their copy. Allow lots of time for questions, showing pictures of biomes, and discussion of the different levels. In particular, pay attention to the fact that the top 3 levels only include living things while the bottom 3 levels include the nonliving environment as well.
  9. Tell students that they should now fill in the center of their pyramid with drawings of their animal within each level. For example, the top should be a picture of their animal by itself as an individual. The next teir should show their animal with others of its species. And so on. If you choose, it is helpful for students to use the right side of the pyramid for a short caption explaining their picture. For example, the second teir might say, “Kody the Koala and the koala bear family and friends that live in his forest.”
  10. Students who take longer to finish the drawings can take them home to finish as homework.

8. Ecosystem Organization - Assessments

Use a quick quiz the following day to test vocabulary retention. For example:

Match the example to the correct word. Write the letter of the correct word in the blank beside the example.

a) ecosystem
b) community
c) biome
d) individual
e) population
f) biosphere 

____    Rosie the rattlesnake                   
____    rattlesnakes, mice, small birds, crickets, grass, hawks, cacti, and tumbleweed               
____    the entire planet Earth                   
____    the community, the water, the air, the rocks, the soil, and the mountains
____    a desert
____    all the rattlesnakes in the area

Going Further


  1. Return to the Field Guide produced from the Food Web activity to discuss and further investigate the community, ecosystem and biome represented by the organisms in the field guide.
  2. Research the Biosphere 2 project in which 5 biomes are replicated in an airtight facility in Arizona. Why was this center built? What scientific questions can be discovered? How is Biosphere 2 similar to Biosphere 1 (the real planet Earth)? How is it different?

8. Ecosystem Organization - Sources and Standards

For more information about biomes around the world, see the Blue Planet Website

For more information about Biosphere 2, see the official website of Biospheres 2 or this Biosphere site that contains additional information about the research and history of the project.

Grade 6
Ecology (Life Sciences)
5. Organisms in ecosystems exchange energy and nutrients among themselves and with the environment. As a basis for understanding this concept:
c. Students know populations of organisms can be categorized by the functions they serve in an ecosystem.
d. Students know different kinds of organisms may play similar ecological roles in similar biomes.
e. Students know the number and types of organisms an ecosystem can support depends on the resources available and on abiotic factors, such as quantities of light and water, a range of temperatures, and soil composition.