Tài liệu Environmental Science (Specialized English for Environmental Courses) ppt

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VO DINH LONG

Environmental Science

(Specialized English for Environmental Courses)

PART 1

PRINCIPLES OF ENVIRONMENTAL SCIENCE

Ho Chi Minh University of Industry Publishing House, 2011

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PREFACE

This book is basically the result of six years of teaching in the

field of environmental science. Some of my graduate and

undergraduate students using this book have been being

engineers, practitioners, and officers. I am very grateful to them

for their patience and tolerance as it progressed from crude

lectures to its present book.

This book is divided into 5 chapters:

Chapter 1: Basic units of ecology.

Chapter 2: Materials and nutrient cycles.

Chapter 3: Humankind’s invention with nature.

Chapter 4: The pollution problems.

Chapter 5: Sustainable development and the future.

Many problems are discussed in the book include: the

ecosystem; materials and nutrient cycles; balance of nature;

progress in agriculture, engineering, and medicine; adverse

effects of people’s activities; air, water and soil pollution;

pollution reduction; how the global environment faces; and the

meaning of sustainable development.

Although this book contributes by one person for the purpose

of teaching and reading. I am lucky to have the supports from so

many people and without their helps this book would not have

been published. While most people did not help directly on my

theme, one of them contributed in some ways towarded helping

me.

Many thanks to my colleagues at Ho Chi Minh University of

Industry: Prof. Le Huy Ba for reading my book and offering

valuable advice; Miss. Nguyen Le Kim Cuong and Mrs. Nguyen

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Thi Thu Thuy for using my crude lectures for their teaching, and

Miss. Nguyen Thi Hong Nhung for her reading and

commending.

I would also like to thank all of them for numerous hours

they have allowed me to spend with them in discussing my

book, confirming reading notes, and helping me with this book.

The most importantly of all, my thanks also to the editorial

staff of Ho Chi Minh University publishing house for their

patience with me in reading, reviewing, and publishing this

book.

Ho Chi Minh City, June 2011

Author

VO DINH LONG

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CONTENTS

Chapter 1: Basic units of ecology

§1. The ecosystem

§2. Components of an ecosystem

Vocabulary

Questions

Chapter 2: Materials and nutrient cycles

§1. Importance of the nutrient cycles

§2. the water cycle

§3. the carbon and oxygen cycle

§4. the nitrogen cycle

§5. the phosphorus cycle

Chapter 3: Humankind’s invention with nature

§1. Balance of nature

§2. Progress in agriculture, engineering, and medicine

§3. Adverse effects of people’s activities

Chapter 4: The pollution problems

§1. Meaning of pollution

§2. Air pollution

§3. Land and soil pollution

§4. Radiation and its harmful effects

§5. Pollution reduction

Chapter 5: Sustainable development and the future

§1. The global environmental situation

§2. Suistainable development

Glossary

Metric unit conversion tables

References

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CHAPTER 1: BASIC UNITS OF ECOLOGY

After studying this chapter, you should be able to:

1. Define environment.

2. Define an ecosystem.

3. Identify the components of the biosphere.

4. Describe the living and nonliving components of the

environment.

5. Explain that bacteria and fungi are agents of decay.

6. Discuss the process of photosynthesis.

7. Enumerate the important factors that affect the growth of

plants and the survival of animals.

§1. THE ECOSYSTEM

When God created the world, He said, “Let the earth

produces all kinds of plants, those that bear grain and those that

bear fruit”, and it was done. Then He also created animals,

including human beings and provided light. God, therefore, saw

to it that everything needed for them to live is found in the world

which He created. He provided spaces, ways and means by with

different organisms can interact with one another and with their

environment.

Part of the world where life operates is known as the

biosphere.

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The biosphere consists of the air (atmosphere), water

(hydrosphere), and earth (lithosphere) where living things

interact with their environment.

When you study the interaction or relationship between

organisms and their environment, you are studying an

ecosystem. The term ecosystem refers to all the living things and

the nonliving things in a given area. It includes all the plants and

animals together with their surroundings.

Figure 1.1: The biosphere

The ecosystem of an aquarium, for example, consists of the

hydrilla and others plants, fish, snails, and other aquatic animals,

some of which can only be seen under the microscope. It also

includes sand and pebbles at the bottom. We can also include

the owner who takes care of the aquarium.

A grassland, too, is an ecosystem. This ecosystem consists of

the grass, earthworms, insects, bacteria, soil, water, sunlight, and

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other plants and animals that live on it. The pond is another

example of an ecosystem.

WARM UP

The forest is a more complex ecosystem. Can you identify

some of the components of this ecosystem?

The entire earth can be thought of as an ecosystem. It has an

abundance of different kinds of species of living things which,

although separate by great distances, still react with one another

and with the nonliving world.

In a forest ecosystem, interrelationships among its living and

nonliving components occur. The branches and leaves of trees

help break the force of the rain. Layers of dead leaves and twins

and branches on the forest floor soak up water and prevent rain

from washing soil away. Little water runs off the land. The roots

of trees hold the soil and water on which they depend.

Moreover, when the leaves and branches decay, they become

part of the rich topsoil.

The soil is made up of minerals like silica and clay. They

come from the breakdown of rocks. There are spaces between

the mineral particles which are filled with air and water. Roots

of plants penetrate deeper into the soil causing physical change.

They loosen the tightly packed particles. Chemical change also

occurs. The roots absorb the minerals present.

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Figure 1.2: Plant-soil relationship

There are thousands of organisms that live in the soil, like

earthworms, that decompose the dead plants and animals. Some

are too small to be seen, but they all help maintain the ecological

balance in the soil.

Figure 1.3: Organisms in the soil

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GUIDE QUESTIONS

1. What is an ecosystem?

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2. How do the living components of an ecosystem affect the

nonliving components? Give example.

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3. Can a fallen log be considered as an ecosystem? Explain

your answer.

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§2. COMPONENTS OF AN ECOSYSTEM

In the preceding section you learned what an ecosystem is.

The living component is known as the biotic and the nonliving

component is known as abiotic. The biotic component consists

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of plants, animals, and bacteria. The abiotic component includes

all the factors of the nonliving environment such as the

substratum, light, rainfall, nutrients, soil, and others. Both the

biotic and abiotic components are equally important in the

ecosystem because without one of them the ecosystem would

not function.

INSIGHTFULNESS

The ecosystem consists of the biotic and abiotic components.

The biotic components are the plants, animals, and

decomposers. The abiotic components are the nonliving factors,

such as temperature, water, and others. The abiotic affect the

biotic components and vice versa.

1. Green plants

Green plants are known as the producers. They capture

energy from the sun and together with carbon dioxide (CO2) in

the air and water (H2O) converting together those into food

energy. Since plants are able to manufacture their own food,

they are also known as autotrophs (or self-nourishing). These

plants are able to manufacture food though the process of

photosynthesis, which will be explained in the next section.

Green plants also take substances, such as nitrogen and sulfur

from the environment and convert those into plant materials that

can be used by other organisms as food. These green plants

further provide oxygen which is taken in by humans and animals

in the process of respiration. For these reasons, all life, whether

in the pond, forest, or grassland, depend on green plants.

You might think that green plants consist only of the trees or

big plants that you see around. The other producers are invisible

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to your eyes. These are the microscopic drifting plants which are

greater sources of food than the big plants that you can see. We

call these microscopic plants phytoplankton. When they become

too abundant, they can give a pond or a body of water a green

color, it is called Eutrophication (Eutrophication is an increase

in the concentration of chemical nutrients in an ecosystem to an

extent that increases the primary productivity of the ecosystem).

WARM UP

Have you ever seen a pond or a lake with green surface?

GUIDE QUESTIONS

1. What are producers?

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2. What do producers perform in an ecosystem?

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3. What is phytoplankton?

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2. Animals

Animals, or the consumers, obtain their food from plants or

other animals. Because of this, they are also known as

heterotrophs, which means that they feed on others and cannot

manufacture their own food, unlike the green plants.

There are three different types of consumers, namely, the

herbivores, the carnivores, and the omnivores.

Figure 1.4: There are three different types of consumers

The herbivores are those that eat plants only. For example,

the caterpillar that feeds on leaves is an herbivore while the

snake that eats the caterpillar is a carnivore. Omnivores eat both

plants and animals. A human being is a good example of an

omnivore.

Through the process of respiration, animals combine the food

they eat with oxygen to produce CO2 and H2O which are used

by plants in the photosynthesis process. Animals also convert

the materials of the plant bodies into the materials that make-up

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their own bodies. All the energy produced and used by animals

comes from the plants.

GUIDE QUESTIONS

1. What are consumers?

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2. What are the three types of consumers? And give one

example for each type.

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3. Bacteria and fungi as agents of decay

Have you ever observed what happen to leaves that fall on

the ground?

After some time, the leaves wither, break down into smaller

pieces, decay, and finally become part of the soil. What do you

think is responsible for this change?

WARM UP

Have you heard of the word decomposer? What do you think

does a decomposer do?

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Decomposers make-up the third biotic component of the

ecosystem. They use the bodies of dead animals and plants for

their food. The materials contained in these dead bodies are

broken down by the decomposers, thus they get the energy they

need and release the minerals and other nutrients back into the

environment for use again by other organisms. Bacteria are

among the most abundant decomposers while fungi are known

to be the fast-acting decomposers.

Decomposers are found everywhere. In the pond, they are

abundant at the bottom where the remains of the dead organisms

(plants and animals) settle. On land, they abound on the surface

of the soil where the dead bodies of plants and animals are

found.

Each of the three groups of the biotic component of the

ecosystem - producers (plants), consumers (animals), and

decomposers (bacteria and fungi) - has its own specific function

or task to perform.

Figure 1.5: Relationship among biotic component of the ecosystem

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The work performed by an organism is known as its

ecological niche, while the place where the organism lives in the

ecosystem is known as its ecological habitat.

GUIDE QUESTIONS

1. What are decomposers?

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2. What do decomposers perform in the ecosystem ?

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