Introduction to Ecosystems

El Paso Independent School District6th Grade Science

Objectives

• In this presentation we will:– Name and describe some of the biotic and abiotic

factors in an ecosystem.– Understand some of the interactions within an

ecosystem.– Visualize the levels of organization in an

ecosystem.

What is an ecosystem?

• An ecosystem is a place or area where living and non-living factors interact in complex ways.

• The living parts of an ecosystem are called BIOTIC FACTORS.

• The non-living parts of an ecosystem are called ABIOTIC FACTORS.

• Examples of ecosystems include: forest, lake, desert, stream, etc.

Ecosystem Factors

Biotic Factors (living)• Animals

– Vertebrates– invertebrates

• Plants– Flowering– Non-flowering

• Fungi– Mushrooms– mold

• Protists– Animal-like– Plant-like– Fungus-like

• Bacteria– Helpful– Harmful

Abiotic Factors (non-living)• Sun• Heat• Light• Temperature• Rocks• Soil• Water• Air• Clouds• Wind• Precipitation• Mountains

How do you know if something is living?

• It is made of cells.• It can grow and develop.• It can reproduce and repair.• It can respond to surroundings.• It uses energy and chemicals.

Look at the picture below. Make a list in your journal/notebook of all the biotic and abiotic factors that you see (answers on next slide.)

Answers

Biotic Factors• Trees• Grass• Insects• Algae• Protozoans• Bacteria• Plankton• Rotting log• Fungi• Kangaroo• Termites• Snail• Frog• Bird• Fish• Snake• Lilly• Bushes• Cattail plants

Abiotic factors• Sunlight• Heat• Clouds• Dirt/soil • Water• Termite mound (the mound

is not alive)• Rocks• Air

Make the graphic organizer below in your interactive notebook

On the inside of the flaps add these titles

Determine if the following factors are abiotic or biotic and list them on the

inside flaps of your graphic organizer.

Your teacher will have your share your lists with your shoulder partner once the class is done.

• Sun• Deer• Grass• Rock• Mouse• Snake• Dirt

• Water• Hawk• Temperature• Cactus• Oxygen• Carbon• Coyote

Check your answers and complete the center of your graphic organizer.

1. Why do the majority of desert animals come out at night?

2. Is the answer to question #1 an abiotic or biotic factor?

3. Do biotic factors need abiotic factors or do abiotic factors need biotic factors? Explain your choice.

4. Give 3 examples from your desert ecosystem of how abiotic and biotic factors interact.

Make the graphic organizer below to take notes and add pictures on the

levels of organization in an ecosystem

Levels of Organization in an Ecosystem.

• The smallest unit of an ecosystem is an organism.

• An organism is an individual living thing that belongs to a certain species.

• Two or more organisms of the same species living in an area make up a population.

organism population

Organism to Population

Organism Population All the red-eared sliders in a pond.

All the bald eagles in a mountain range.

All the pine trees in a forest.

Communities

• A community is two or more organisms belonging to different species living in an area.

What does this picture best represent?

a. Species b. Organismc. Populationd. Community

Click for answer

Answer

• It represents a community because there is a population of deer, a small population of geese, and a large tree in the background. Since there are many different species of organisms, the picture best represents a community.

An Ecosystem• Once the abiotic factors are

added to the community, you have an ECOSYSTEM!

Ecosystem Summary

• Ecosystems are areas where complex interactions between biotic and abiotic factors occur.– Biotic factors are living; abiotic factors are non-living.

• All living things:– Are made of cells– Can grow and develop– Reproduce, repair, and respond to surroundings– Uses energy and chemicals

• The levels of organization in an ecosystem are: organism population community ecosystem