CHAPTER 12 LESSON 1 Matter and Energy in the Environment

[Pages:5]Matter and Energy in the Environment

Abiotic Factors

What do you think? Read the two statements below and decide

whether you agree or disagree with them. Place an A in the Before column if you agree with the statement or a D if you disagree. After you've read this lesson, reread the statements to see if you have changed your mind.

Before

Statement

After

1. The air you breathe is mostly oxygen.

2. Living things are made mostly of water.

CHAPTER 12 LESSON 1

Key Concept

? What are the nonliving parts of an environment?

What is an ecosystem?

All organisms need both living and nonliving things to survive. Bees help the flowering plants reproduce. The flowers have nectar that the bees use to make honey. Flowers and bees, like all living organisms, also need nonliving things to survive, such as sunlight, air, and water.

An ecosystem is all the living and nonliving things in a given area. Ecosystems come in all sizes. An entire forest can be an ecosystem. A rotting log, a pond, a desert, an ocean, and your neighborhood are all ecosystems.

Biotic (bi AH tihk) factors are the living things in an ecosystem. Plants and animals are biotic factors. Abiotic (ay bi AH tihk) factors are the nonliving things in an ecosystem. Sunlight, water, and rocks are abiotic factors.

Biotic factors and abiotic factors depend on each other. If one factor in an ecosystem is disturbed, other parts of the ecosystem are affected. During times of water shortages, or severe droughts, many fish in rivers and lakes will die. Animals that eat fish will have to find other food. This abiotic factor, lack of water, affects the biotic factors in the ecosystem, such as the fish and the other animals that feed on the fish.

3TUDY#OACH

Make an Outline As you read, make an outline to summarize the information in this lesson. Use the main headings in the lesson as the main headings in the outline. Complete the outline using the information under each heading.

Reading Check 1. Contrast Underline the major difference between biotic and abiotic factors.

Copyright ? Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Reading Essentials

Matter and Energy in the Environment 189

2. Explain Why would

there be no food for people if there were no water or soil?

What are the nonliving parts of an ecosystem?

Think about the ecosystem around you. How do the abiotic factors in your own ecosystem affect you? You need sunlight for warmth. You need air to breathe. You need water to drink. Without sunlight, air, water, and soil, you would not have food. In the figure below, all of the nonliving parts of the environment affect all living things.

Copyright ? Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Visual Check 3. Identify Highlight the nonliving parts of the ecosystem that affect all living things.

190 Matter and Energy in the Environment

Reading Essentials

Copyright ? Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Precipitation (cm)

The Sun

Almost all energy on Earth comes from the Sun. The Sun provides warmth and light. Many plants use sunlight and make food, as you will read about later. Sunlight is an abiotic factor. The Sun also affects two other abiotic factors--climate and temperature.

Climate

Polar bears live in the Arctic. The Arctic has a cold, dry climate. Climate describes average weather conditions in an area over time. Weather conditions include temperature, moisture, and wind. The graph below shows such conditions.

Climate is an abiotic factor that affects where organisms can survive. A desert climate is dry and often hot. A plant that needs a lot of water could not survive in a desert. A cactus can live in a desert because it can survive with little water.

Temperature (?C)

Climate

30

30

25

25

20

Temperature

20

15

Precipitation

15

10

10

5

5

0 Jan Mar May Jul Sep Nov

0

Month

Temperature

Is it hot or cold where you live? Temperatures on Earth are different every day. Temperature is another abiotic factor that affects where organisms can survive. Some organisms, such as tropical birds, do well in hot temperatures. Other organisms, such as polar bears, do well in cold temperatures. Tropical birds do not live in cold ecosystems. Polar bears do not live in warm ecosystems.

Water

All life on Earth must have water. In fact, most organisms are made mostly of water. All organisms need water to grow and reproduce. Because of this, every ecosystem must contain some water to support life.

Reading Check

4. State For what do living

things use energy from the Sun?

Visual Check

5. Apply In the graph at

the left, which month shows both the highest temperature and the highest amount of precipitation?

Use a six-door book to organize information about the abiotic parts of an ecosystem.

Air

Soil

Water

Temperature

Sunlight

Climate

Reading Essentials

Matter and Energy in the Environment 191

Visual Check 6. Identify How much oxygen is in the air we breathe?

Key Concept Check 7. Name abiotic factors that make up ecosystems.

8. Discuss Name one way

in which soil depends on a biotic factor.

Atmosphere

The atmosphere (AT muh sfir) is the layer of gases that surrounds Earth. The atmosphere is an abiotic factor that is necessary for life. You interact with the atmosphere every time you take a breath.

The atmosphere is mostly nitrogen and oxygen, as shown in the circle graph below. The atmosphere provides oxygen that living things breathe. It also protects them against certain harmful rays from the Sun.

Gases in Atmosphere

Nitrogen 78%

Trace gases 1%

Oxygen 21%

Soil

Soil is an abiotic factor. Soil is made up of bits of rocks, water, air, minerals, and the remains of once-living things. Soil is important for growing crops. It provides water and nutrients to plants.

Soil is also important as a home to many organisms, such as insects, bacteria, and fungi. Factors such as water, soil type, and nutrients in the soil are important to organisms that live in the soil. Organisms live in the soil that suits them best. Bacteria break down dead plants and animals. This returns nutrients to the soil. Earthworms and insects make small tunnels in the soil that water and air move through. Even dry soil in the deserts is home to living things.

Copyright ? Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

192 Matter and Energy in the Environment

Reading Essentials

Mini Glossary

abiotic (ay bi AH tihk) factors: the nonliving things in an ecosystem, such as sunlight and water

atmosphere (AT muh sfir): the layer of gases that surrounds Earth

biotic (bi AH tihk) factors: the living things in an ecosystem

climate: describes average weather conditions in an area over time

ecosystem: all the living things and nonliving things in a given area

1. Review the terms and their definitions in the Mini Glossary. Write a sentence that uses any three of the terms correctly.

2. Think of one of the ecosystems mentioned in the lesson or any other ecosystem you know about. Label the table below with the name of your ecosystem. Then fill in the table to show the abiotic and biotic factors in that ecosystem.

Ecosystem:

Abiotic Factors 1. 2. 3. 4. 5.

Biotic Factors 1. 2. 3. 4. 5.

3. How did the outline you made of the main ideas in this lesson help you review the material?

Copyright ? Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

What do you think

Reread the statements at the beginning of the lesson. Fill in the After column with an A if you agree with the statement or a D if you disagree. Did you change your mind?

Reading Essentials

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END OF LESSON

Matter and Energy in the Environment 193

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