Welcome to the 

World’s Forests edition 

of the Natural Inquirer! 

Winter 2008

© Food and Agriculture Organization (FAO)

of the United Nations

United States Forest Service

Jan Heino

Assistant Director-General 

Forestry Department, FAO

Abigail Kimbell

Chief

US Forest Service, Washington, DC

Ann Bartuska

Deputy Chief for Research

Jim Hubbard

Deputy Chief for State and 

Private Forestry

With thanks to:

Safi ya Samman 

Staff Director

Conservation Education

US Forest Service

John Sebelius 

Staff Director

Science Quality Services

US Forest Service

Alex Comfort

Executive Director

Cradle of Forestry In America 

Interpretive Association

Andrea Perlis, Laura Russo, Mette Wilkie

Forestry Department, FAO

Editor:

Babs McDonald

US Forest Service

Layout:

Giulio Tiberi

The Natural Inquirer is an integrated 

science education journal for students 

aged 11-14. In the United States where 

the journal was fi rst published, the 

Natural Inquirer presents research from 

scientists working in the United States 

Department of Agriculture’s Forest 

Service. 

This edition of the Natural Inquirer

presents the results of a worldwide 

effort to understand the world’s forests, 

organized by the United Nations Food 

and Agriculture Organization, or FAO. 

The report from which this Natural 

Inquirer is written is the Global Forest 

Resources Assessment 2005. It contains 

information from 229 countries and 

territories around the world. 

You can access the FAO report at 

http://www.fao.org/forestry/fra2005/

Visit:

http://www.naturalinquirer.usda.gov 

http://www.fao.org/forestry/site/fra

http://www.fao.org/kids/en/forestry.html

for more information and 

to fi nd this journal online!
WELCOME TO THE WORLD’S FORESTS EDITION OF THE 

NATURAL INQUIRER!

THINKING ABOUT THE ENVIRONMENT

THINKING ABOUT SCIENCE

INTRODUCTION TO THE INQUIRIES

INQUIRY 1: WHAT KIND OF FORESTS GROW ON EARTH 

AND HOW DO THEY DIFFER?

INQUIRY 2: HOW MUCH OF EARTH’S LAND IS COVERED BY 

FORESTS?

INQUIRY 3: HOW MUCH CARBON IS BEING HELD BY THE 

WORLD’S FORESTS?

INQUIRY 4: HOW WELL ARE WE MANAGING OUR FORESTS 

WORLDWIDE?

EDUCATOR RESOURCES

NOTE TO TEACHERS

LESSON PLAN FOR WELCOME TO THE WORLD’S FORESTS 

EDITION

LESSON PLAN FOR THINKING ABOUT THE ENVIRONMENT

LESSON PLAN FOR THINKING ABOUT SCIENCE

LESSON PLAN FOR INTRODUCTION TO THE INQUIRIES

LESSON PLAN FOR INQUIRY 1

LESSON PLAN FOR INQUIRY 2

LESSON PLAN FOR INQUIRY 3

LESSON PLAN FOR INQUIRY 4

REFLECTION ANSWER GUIDE

EDUCATIONAL CONCEPTS ADDRESSED BY THE INQUIRIES

EDUCATORS! Go fi rst to the educator resources section on page 27.

TABLE OF CONTENTS

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5

6

7

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18

21

27

28

29

29

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29

30

32

34

35

37

39

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4

Have you heard of the United 

Nations? The United Nations 

(UN) is a world organization 

that was established in 1945. 

Today, nearly every nation 

in the world belongs to the 

UN. In total, 192 countries 

are members of the UN. 

These nations are working 

together for peace, human 

rights, freedom, and social 

progress.

The Food and Agriculture 

Organization, or FAO, is a 

part of the United Nations. 

FAO helps developing 

countries and countries in 

transition modernize and 

improve agriculture, forestry, 

and fi sheries practices. FAO 

also helps these countries 

provide good nutrition for all. 

For many years, FAO has 

been collecting information 

about the world’s forests. 

It may seem unusual for 

an organization concerned 

with food and agriculture to 

WELCOME TO THE WORLD’S FORESTS 

EDITION OF THE NATURAL INQUIRER!

be studying forests. Trees, 

however, can be important 

for the nutrition of people. 

Trees have many links to 

agriculture. They help protect 

soil and water necessary 

for food crops. People use 

forests and plant trees for the 

many benefi ts trees provide, 

including food, energy, 

wood products, construction 

materials, and medicines. 

Trees also help protect the 

environment. 

Trees are often planted in 

a manner similar to food 

crops, except that it takes 

many years for trees or 

their products to be ready 

for harvesting (Figure 1). 

The more knowledge FAO 

can collect about trees 

and forests, the more 

successfully it can help 

countries like yours grow 

and manage healthy forests. 

More information also helps 

Figure 1. A young forest plantation in the United States. Photo by 

Dave Powell, USDA Forest Service 

your country take better 

advantage of forest benefi ts. 

These benefi ts improve the 

lives of all people. 

In this edition of the Natural 

Inquirer, you will learn about 

the world’s forests. Take a 

moment to think about the 

size of the planet. Because 

it is so large, you will learn 

about large areas of forests. 

FAO divided the world into 

regions and subregions 

(Figure 2). Most of the 

information in this journal is 

presented according to these 

regions or subregions. For 

example, Africa is considered 

one region. The three 

subregions of Africa include: 

Eastern and Southern Africa, 

Northern Africa, and Western 

and Central Africa. Take a 

moment to fi nd the region and 

subregion where you live.

with food and agriculture to 

GLOSSARY:

transition: The 

act or process of 

passing from one 

condition, form, or 

place to another.

modernize: To 

make or become 

modern; to bring up 

to date.

YOU DO THE MATH: 

How old is the 

UN today?
5

Africa

Eastern and Southern Africa

Northern Africa

Western and Central Africa

Asia

East Asia

South and Southeast Asia

Western and Central Asia

Europe

Europe

North and Central America

Caribbean

Central America

North America

Oceania

Oceania

South America

South America

Others

Antarctica

Water

Figure 2. Regions and subregions of the world

Forests are important 

to the lives of all people 

everywhere. Worldwide, 

people benefi t from the 

world’s forests, even if those forests are 

not found in their own community. Forests 

provide materials such as wood for building 

or for energy. Forests provide food for people 

and for animals. They provide habitat for 

many different kinds of plants and animals, 

which helps to maintain the diversity of life on 

Earth (Figure 3). Forests protect the quality 

of water and help keep the soil from eroding. 

Forests help keep the air clean and they 

provide places for people to live and play. In 

many places, forests provide jobs which help 

people and their families have a better life.

Note: Italicized words are defi ned on page 6. 
6 Figure 3. Forests provide habitat for wildlife

When scientists want to 

learn something, they 

must collect information. 

Although you might not 

realize it, you do the same thing when you 

want to learn something. This information 

is called data, and it is often collected in 

the form of numbers. If scientists collect 

data in the form of numbers, they can add, 

subtract, multiply, or divide the numbers, 

and they can calculate new numbers like 

averages. Numbers help scientists compare 

information collected from different places or 

times. This is more complicated than it fi rst 

appears. The numbers coming from different 

places or times must have the same unit of

measurement. Otherwise, the calculations will 

be meaningless. 

For example, let’s say a scientist wants 

to calculate an average temperature for 

one month across the entire Northern 

Hemisphere. Some temperatures are reported 

in Celsius and some in Fahrenheit. Would 

an average of those measurements allow a 

meaningful conclusion? Of course not! The 

scientist would have to change each number 

to the same unit of measurement. Only then 

could an average temperature be calculated.

This same scientist has found that 

some countries, when reporting a daily 

temperature, used the highest temperature 

measured each day. Other countries used 

an average temperature, calculated over 

a 24-hour period. Would an average of 

these measurements allow a meaningful 

conclusion? Again, the answer is no. When 

numbers are intended to be combined in 

some way, they must represent the same 

thing or calculations done with them are 

meaningless.

The scientists in this study wanted to learn 

about forests across the globe. To collect 

accurate data, they worked with an individual 

GLOSSARY:

habitat: Environment where a plant or 

animal naturally grows and lives. 

diversity: A measure of the differences 

between the types and numbers of 

living things in a natural area.

erode: To wear away.

average: The usual kind or amount. 

The number gotten by dividing the 

sum of two or more quantities by the 

number of quantities added.

unit of measurement: A standard 

quantity of a physical property, such as 

meters, degrees Celsius, or grams.

Northern Hemisphere: The half of 

Earth that is north of the equator.

correspondent: In the context of 

FRA 2005, a correspondent is a 

representative from each country who 

gathered and sent information to FAO.
7

in each country, called a correspondent

(Figure 4). The correspondent provided 

his or her country’s data to FAO. Each 

correspondent worked with FAO to ensure 

the numbers being collected represented the 

same thing. This enabled the scientists to 

add the numbers from different countries. In 

this way, the scientists were able to create a 

report about the world’s forests.

INTRODUCTION TO THE INQUIRIES

of the challenges and opportunities are the 

same wherever forests are found.

For each of the four Inquiries presented in 

this journal, FAO and the correspondents 

followed the same process to collect data. 

When the data were added together, 

it provided information about forests 

subregionally, regionally, and globally. 

Next, we will take a look at the information 

collected by country correspondents and 

provided to FAO in these four Inquiries. If you 

want to learn more about the entire report 

about the world’s forests, visit:

http://www.fao.org/forestry/fra2005

This journal contains four Inquiries. Each 

Inquiry represents a study done by FAO 

scientists and country correspondents to 

answer a specifi c question about the world’s 

forests. By the time you complete all four 

Inquiries, you will know several new facts 

about forests across the world. 

Each Inquiry builds on the previous Inquiry. It 

is best, therefore, to read the Inquiries in the 

order presented. As you read about FAO’s 

work to collect data about the world’s forests, 

think about the forests you have seen, visited, 

or read about. Although there are differences 

between forests around the world, many 

What are some of the 

benefi ts forests provide 

to your community?

REFLECTION 

SECTION

Figure 4. The country correspondents met to discuss their work

Mr. Brad Smith is the 

National Correspondent 

from the United States. 

We asked Mr. Smith 

what he likes best 

about this important job and he said: 

“working closely with scientists from 

all over the world. I like discussing 

environmental issues and discovering 

new ways of thinking and solving 

problems. By working together, we 

improve our data gathering and reporting 

both at home and across the globe. 

I also liked discovering that some of the 

smallest countries have some of the 

most creative ideas."
8

INQUIRY 1: WHAT KIND OF FORESTS GROW 

ON EARTH AND HOW DO THEY DIFFER?

THE SITUATION: Across the planet, different 

types of forests are found. One reason 

different forest types exist is because they 

grow under different climates (Figure 5). 

Another reason is that human activities have 

changed some of the forests, for example 

through planting or felling of trees. To better 

understand the different types of forests 

found across Earth, the scientists had to 

decide what was most important about those 

forest differences to study. In other words, to 

study the differences between forests across 

the planet, FAO had to determine how they 

would classify forests.

Before we learn how FAO classifi ed the 

world’s forests, let’s think about the place on 

which these forests grow. What is this place 

called?

If you guessed Earth, you are right! We know 

that Earth spins on its axis and revolves 

Figure 5. World ecozone map. An ecozone is a region with similar type of land cover. Notice that 

similar ecozones can occur on different continents

Legend

TAr Tropical rainforest

TAwa Tropical moist deciduous forest

TAwb Tropical dry forest

TBSh Tropical shrubland

TBWh Tropical desert

TM Tropical mountain system

SCf Subtropical humid forest

SCs Subtropical dry forest

SBSh Subtropical steppe

SBWh Subtropical desert

SM Subtropical mountain system

TeDo Temperate oceanic forest

TeDc Temperate continental forest

TeBSk Temperate steppe

TeBWk Temperate desert

TeM Temperate mountain system

Ba Boreal coniferous forest

Bb Boreal Tundra woodland

BM Boreal mountain system

P Polar

 Water

 No data

GLOSSARY: 

climate: The average condition of the 

weather over large areas, over a long 

time, or both.

classify: To arrange by putting into 

groups according to some system.

axis: A straight line about which a 

body or geometric fi gure rotates.

equator: An imaginary circle around 

the middle of Earth at an equal 

distance from the North Pole and the 

South Pole.

conserve: To avoid wasteful or 

destructive use of something.

latitude: Distance north or south of the 

equator.
9

Figure 6. Earth spins on its axis and revolves around the sun

Figure 7. Earth is warmer near the equator, cooler near the poles

Mountain-top ice and snow

Alpine tundra (herbs, lichens, mosses)

Evergreen forest

Deciduous forest

Tropical forest

Sea Level

Elevation

Climate

Cooler

Warmer

Figure 8. The higher the land’s elevation, the cooler its climate

North Pole (90o latitude)

Cooler

temperatures

Warmer

temperatures

Earth’s

Northern

Hemisphere

Polar (ice)

Temperate forests (oceanic forests, continental forests),

steppe, deserts, mountains

Boreal forests (coniferous[with cones]),

tundra, mountains

Subtropical forests (humid forests, dry forests), steppe,

deserts, mountains

Tropical forests (rain forests, dry forests, deciduous forests),

shrubland, deserts, mountains

Equator (0o latitude)

Figure 9. Vegetation types, temperature, and latitude

around the sun (Figure 6). 

The area near the equator is 

closest to the sun. Because of 

this, Earth is warmest near the 

equator, and coolest near the 

poles (Figure 7). 

About 71 percent of Earth is 

covered with water, and most 

of this is ocean. The top level of 

any ocean is called sea level. 

The height of the land compared 

with sea level is called elevation. 

At higher elevations, the climate 

is cooler (Figure 8). 

Across Earth, different areas 

receive different amounts of 

rainfall. 

Plants need water to survive 

and have adapted over time 

to live with varying amounts of 

rainfall. Some plants, such as 

those in tropical rain forests, 

must have a lot of water to 

survive. Other plants, like those 

in deserts, do not need much 

water to survive. Desert plants 

have adapted to conserve the 

amount of water they receive. 

Drier areas have fewer plants 

and trees. Some areas have 

no plants or trees at all. The 

3 things that we have just 

explored are latitude, elevation, 

and rainfall (Figures 7-10). They 

affect what kind of forest grows 

naturally in a particular area on 

Earth (Figures 9-10 and 12).

In addition to latitude, elevation, 

and rainfall, there is another 

infl uence on Earth’s forests. This 

infl uence is changing Earth’s 

forests, no matter where on Earth 

the forests are located. It was 

this infl uence FAO was most 

interested in understanding. What 

infl uence did the scientists want 

to understand?
10

Warm

Temperature

Cool

Dry Rainfall Wet

Poles

Latitude

Equator

Deserts

Deserts

Tundra

Steppe

Steppe

Grasslands

Tropical shrublands

Tropical dry forests

Tropical

rain

forests

Deciduous forests

Deciduous forests

Tundra Tundra

Boreal forests Boreal forests

Figure 10. Vegetation types, temperature, and rainfall

If you guessed humans, you are 

right! FAO wanted to understand 

how forests are changing as a 

result of human activity. To study 

the infl uence of humans on 

forests, the scientists classifi ed 

forests into fi ve categories 

(Table 1, page 11). These 

categories were based on how 

much humans have changed 

the forest.

If humans have not changed 

a forest much at all, that forest 

is made up of native plant and 

tree species. Native species are 

those that are found in the area 

naturally (Table 1, page 11 and Figure 12 , 

page 12).

Not all forests are made up of native species, 

and not all forests get their start naturally. 

Trees are planted by people for many reasons. 

People plant trees to harvest timber in the 

future and for other wood products such as 

pulp for making paper. When people plant 

trees for these kinds of products, the resulting 

forests are called productive plantations.

Of course, trees are also planted for food 

products such as fruits and nuts, but the result 

of these plantings are mostly fruit orchards. 

Fruit orchards were not included among the 

forest categories by FAO. 

People also plant trees to achieve 

environmental benefi ts. Trees may be planted 

to protect streams and rivers and to keep soil 

from eroding, a practice called soil and water 

conservation. When people plant trees to 

conserve water quality and soil, the resulting 

forests are called protective plantations.

After FAO had classifi ed forests according 

to human activity, they were ready to 

discover how humans were infl uencing the 

world’s forests. They asked each country 

correspondent to provide information about 

the characteristics of their country’s forests 

according to the categories in Table 1 for the 

years 1990, 2000, and 2005.

GLOSSARY: 

native: Naturally occurring in an area.

species: Groups of organisms that 

resemble one another in appearance, 

behavior, chemical processes, and 

genetic structure.

ecological: Having to do with ecology, 

the study of organisms and their 

relationship with their environment.

environmental services: The 

collection of environmental processes 

that provide benefi t to life on Earth.

conservation: The care and protection 

of natural resources such as forests 

and water.

ecosystem: A community of 

organisms living in an environment as 

an interdependent system.

WHAT THEY DISCOVERED: In 2005, slightly

more than half of all forest area worldwide was

classifi ed as modifi ed natural forest (Figure 

11). Remember that modifi ed natural forests 

contain native tree species that have grown 

naturally but show some signs of human 

activity. 

In 2005, more than one-third of the world’s 

total forest area was classifi ed as primary 

forest showing no signs of human activity. 
11

The largest area of primary forest was in the 

Amazon region of South America. Seven 

percent of the world’s forests were seminatural. Productive and protective plantations 

only made up 3.8 percent of total forests 

worldwide. Of this 3.8 percent, 3 percent was 

in productive plantations.

Table 1. Categories of forests identifi ed by FAO

CATEGORY OF 

FOREST 

CHARACTERISTICS

DESCRIPTION OF FOREST 

WITHIN EACH CATEGORY

Primary forest Forests with native tree species. Evidence of human 

activities is not visible and the forest’s ecological

processes are not widely disturbed. 

Modifi ed natural forest Forests with native tree species that have grown 

naturally. There is evidence of human activities in a 

modifi ed natural forest. An example is an area where 

some trees were cut in the past. 

Semi-natural forest Forests with native tree species that have grown 

because humans have either sown seeds or planted 

small trees, or have otherwise assisted the growth of 

native tree species.

Productive forest plantation Man-made forests with mostly non-native (and in some 

cases native) tree species. These forests have been 

purposely planted by humans for the production of wood 

products or non-wood forest products. People create a 

productive plantation by sowing seeds or planting small 

trees.

Protective forest plantation Man-made forests with mostly non-native (and in 

some cases native) tree species that have been 

purposely planted by humans for environmental 

services.

You Do the Math: 

What percentage of forest 

land worldwide was 

classifi ed as either modifi ed 

natural forest or primary 

forest?

You Do the Math: 

How many hectares of 

productive plantations are 

added every year? How 

many hectares of protective 

plantations are added every 

year? 

Primary forest

Modified natural forest

Semi-natural forest

Productive forest plantation

Protective forest plantation

36.4%

52.7%

7.1%

3.0%

0.8%

Figure 11. Forest characteristics: percent worldwide in each 

category

Between 1990 and 2005, the areas of primary 

forest and modifi ed natural forest were 

decreasing worldwide. The areas of seminatural forest and forest plantations increased 

over the same period. Each year since 1990, 

about 6 million hectares of primary forest 

have been lost or modifi ed. About 2.8 million 
12

Figure 12. Some native ecosystems
13

1990 2000 2005

0 200 400 600 800 1 000 1 200 1 400 1 600

Primary

forest

Modified

natural

forest

Semi-natural

forest

Productive

forest

plantation

Protective forest

plantation

million ha

Figure 13. Changes in different categories of forests from 1990 to 

2005 (million hectares)

Describe 

the majority 

of forests 

worldwide. 

You can 

either use one or two 

categories to do this. 

What are two major trends 

in the categories of forests?

REFLECTION 

SECTION

hectares of forest plantations 

are added every year. Of these, 

87 percent are productive 

plantations (Figure 13).

Forest

Other land

Other wooded land

Water

THE WORLD'S FORESTS
14

INQUIRY 2: HOW MUCH OF EARTH’S LAND IS 

COVERED BY FORESTS?

THE SITUATION: You have learned about 

the benefi ts forests provide to people and 

other animals. (If you have not read “Thinking 

about the Environment,” please do so now.) 

In Inquiry 1, you also learned that people are 

changing the world’s forests. What you did 

not learn, however, is whether the world’s 

forests are growing or shrinking in size 

overall.

Throughout history, humans have cut down

trees and planted trees to meet their needs

(Figure 14). This is one of the benefi ts of trees! 

If humans remove more trees than they plant, 

however, the size of the forest will shrink. 

FAO wanted to know whether Earth is losing, 

gaining, or keeping about the same amount 

of forests over time. To do this, they asked 

each country correspondent to provide 

information for the years 1990, 2000, and 

2005. The information they collected included 

the total amount of forests in all categories 

for each correspondent’s country.

WHAT THEY DISCOVERED: In 2005, the 

total amount of forests worldwide was just 

under 4 billion hectares. This is equal to 

about 30 percent of the land area on Earth. If 

every person on Earth were given an equal 

piece of forest, each person would have 0.62 

of a hectare, which is about the size of a 

soccer fi eld (Figure 15). 

Some countries have a large population

and a small amount of forest. For those 

countries, each person might be given an 

area smaller than 0.1 hectare (about 1/6 of a 

soccer fi eld). In other countries, there is a 

large amount of forest compared with the 

population. In the largest of these countries, 

each person might be given over 5 hectares 

of forest, or about 8 soccer fi elds. You can 

see that the amount of forests across Earth is 

not evenly distributed among the world's 

human population.

The removal of trees and conversion of the 

land to another use is called deforestation. 

Most deforestation happens because people 

remove trees and plant food crops for people 

and for livestock (Figure 16). Worldwide, 13 

million hectares of forests are lost to 

deforestation every year.

Fortunately, people are also planting trees 

and helping forests grow back. In addition, 

some forests have naturally spread over a 

larger area without help from people. 

Do you think FAO found 

that Earth is gaining, 

losing, or keeping about 

the same amount of forests 

over time?

If more forests are lost than are being 

planted, what will happen to the benefi ts 

provided by forests?

REFLECTION 

SECTION

Figure 14. Young man watering trees to stabilize 

sand dunes 
15

You Do the Math: 

How many fewer hectares of 

forest land were being lost 

each year between 2000 and 

2005 compared with the 

decade between 1990 

and 2000?

There are 100 hectares in a 

square kilometer (km2

). 

How many km2

 did Earth lose 

per day during 2000-2005?

The size of a soccer (or

football) field is the average

amount of forest available for

each person on Earth. For countries

with a large

amount of

forest and a 

small

population,

each person

may have an 

average of 

this much

forest.

For countries with 

a large population

and a small

amount of forest,

each person may

have an average

of this much forest.

South America

Africa

Asia

Europe

North and Central America

Oceania

1990-2000

2000-2005

Annual net change in forest area

Figure 17. Changes in the amount of forest area by region 

(million hectares per year)

Figure 16. Land planted for food crops

Figure 15. Average amount of forest for every person on Earth 

and the range of forest from the smallest amount per person to 

the largest amount per person

Because some forests were 

expanding but more were 

being lost worldwide, about 7.3 

million hectares of forests - an 

area about the size of Sierra 

Leone or Panama - were lost 

every year between 2000 and 

2005. While this is not good 

news, it is better news than in 

the past. Between 1990 and 

2000, about 8.9 million 

hectares of forests were lost 

every year.

Why is it 

important to 

understand 

whether the 

amount of 

forest area 

worldwide is 

shrinking, growing, or 

staying about the same?

Look at Figure 17. Find the

region where your home is 

located.

How does your region 

compare with the rest of 

the world?

Why do you think that is?

REFLECTION 

SECTION
16

Between 2000-2005 South America lost 

more hectares of forests than any other 

region (Figure 17). Africa also lost a large 

amount of forests. On the other hand, Asian 

forests grew by one million hectares every 

year between 2000 and 2005. Asia’s 

increase in forests was the result of a 

planned effort to plant trees in that region. 

Most of the trees were planted in China.

Figures 18-21 show four world maps. The 

fi rst map (Figure 18) is easy to recognize, 

because each country is its normal size and 

shape. The countries within each region are 

similarly colored. Find your own country and 

region on this world map. What general color 

is the region in which your country is located? 

The maps in Figures 19-21 are called 

cartograms. In cartograms 19-21, the country 

size and shape is distorted to show the 

country’s forest area, forest growth and forest 

loss in relation to the country's size. In Figure 

20, the cartogram shows forest growth in 

Figure 18. Land area of countries across the world. Map by Worldmapper

Figure 19. Amount of forest area in each country in 2005. Map by Worldmapper
17

square kilometers between 1990 and 2005. 

Compared with their normal size and shape, 

the larger countries and regions experienced 

more forest growth during that period. 

In Figure 21, the cartogram shows forest 

loss in square kilometers between 1990 

and 2005. Compared with their normal size 

and shape, the larger and more distorted 

countries experienced more forest loss. Find 

your country and region in the cartograms 

in Figures 20 and 21. Did your country gain 

or lose forests? Did your region gain or lose 

forests? Now compare these cartograms with 

the blue and green bars in Figure 17. What 

do Figures 17, 20 and 21 tell you about the 

forests in Asia?

Figure 20. Amount of forest growth in each country between 1990 and 2005. Map by Worldmapper

Figure 21. Amount of forest loss in each country between 1990 and 2005. Map by Worldmapper

GLOSSARY: 

distort: To twist out of a normal shape.
18

INQUIRY 3: HOW MUCH CARBON IS HELD BY 

THE WORLD’S FORESTS?

THE SITUATION: Carbon dioxide is a gas 

that is made up of carbon and oxygen. 

Carbon dioxide has always been present in 

Earth’s atmosphere. Carbon dioxide plays an 

important role in regulating Earth’s climate 

through a process called the carbon cycle 

(Figure 22). Earth will cool if the carbon cycle 

removes too much carbon dioxide from the 

atmosphere. If the carbon cycle generates 

too much carbon dioxide, Earth will warm.

As you can see from the carbon cycle, carbon 

is both held on Earth and released into the 

atmosphere as carbon dioxide. 

Since the end of the last ice age, the amount 

of carbon dioxide in the atmosphere has 

remained fairly constant. In recent years 

however, the amount of carbon dioxide in the 

atmosphere has been rising. The rising 

amount of carbon dioxide may be related to 

the increase in some types of human activity, 

such as burning fossil fuels. 

From Figure 22, you can see that trees and 

forests play an important part in the carbon 

cycle. As a tree grows, it absorbs carbon 

dioxide from the atmosphere. The carbon 

becomes a part of the living tree, including its 

Do you think Earth’s 

climate could be changing 

due to human activity? 

Why or why not?

REFLECTION 

SECTION

Carbon dioxide in atmosphere

Plant and animal

respiration (during which

carbon dioxide is 

released)

Soil respiration

(during which

carbon dioxide is 

released)

Decaying organisms

on and in soil 

(plants and animals)

Fossil fuels (deep underground)

Plants capture

carbon through

photosynthesis

Transport and 

factory emissions 

from burning 

fossil fuels

Animals

eat plants

Oceans capture

carbon dioxide

Figure 22. The carbon cycle

roots. Most of the carbon stays in the tree 

until the tree is destroyed by fi re or decay 

(Figure 23). Other plant matter in forests also 

contains carbon. Examples include fallen 

leaves, fallen dead wood (Figure 24), and 

shrubs. The soil also contains carbon.

Scientists believe that higher levels of carbon 

dioxide in the atmosphere are causing the 

world’s climate to change. Since trees absorb 

carbon dioxide when they grow and other 

material in forests contain carbon, forests 

help reduce the amount of carbon dioxide 

being released to the atmosphere. FAO 

wanted to discover how much carbon is held 

by forests worldwide. The amount of carbon 

held in a tree is equal to about half the tree’s 

weight after all water has been removed. The 

amount of carbon, therefore, can be 

calculated if the number and size of trees and 

GLOSSARY: 

fossil fuel:

Fuel, such as 

coal, petroleum, 

or natural gas, 

formed from the 

fossilized remains 

of plants and 

animals.
19

4. Some of the carbohydrate 

glucose is sent to the roots.

2.

1. 

3.

5. The ne roots absorb 

water and nutrients 

from the soil and send 

them through the coarse 

woody roots to the trunk, 

branches, and leaves of 

the tree.

6. Some of the below ground carbon stays in the 

roots, and some is released into the soil as carbon 

dioxide. Some of this stays in the soil. Some is 

released back into the atmosphere.

Figure 3. The movement or cycling of carbon by trees. 

 Some carbon dioxide 

is captured by leaves 

during photosynthesis 

and turned into glucose,

a carbohydrate.

Carbon dioxide in atmosphere

carbon dioxide taken 

from atmosphere

carbon dioxide 

released 

KEY

 When leaves, branches, 

trunk and roots use the 

glucose for energy, some 

of the carbon is released 

as carbon dioxide.

Figure 23. Trees absorb, hold, and release carbon

the amount of water 

held in different sizes of 

trees can be estimated.

WHAT THEY 

DISCOVERED: 

Of the 229 countries 

and territories reporting 

to FAO, 151 countries 

provided estimates of 

the amount of carbon 

contained in their 

forests. This accounted 

for 80 percent of the 

world’s forests. Based 

on this information, FAO 

estimated the amount of 

carbon being held by the 

remaining 20 percent of 

the world’s forests. 

Then they added all of 

the information together.

The amount of carbon is 

measured in 

gigatonnes, and is 

written Gt. One Gt is 

equal to 1 billion tonnes. 

One tonne is equal to 

1,000 kilograms or 

2,205 pounds. In 2005, 

the total amount of 

carbon in forests was 

estimated to be 638 Gt 

(Figure 25). 

This is more than the 

total amount of carbon 

in the entire 

atmosphere! This fi gure 

includes all forest 

vegetation, roots, dead 

wood, and the carbon 

contained in the soil. 

Worldwide, there was a 

slight decline in the 

amount of carbon in the 

world’s forests from 1990 

to 2005.

Fig 24. Plant matter found on the forest fl oor contains carbon

Africa

Asia

Europe

North and 

Central America

Oceania

South America

C in biomass C in dead wood C in litter C in soil

0 20 40 60 80 100 120 140 160 180 200

Gt

Fig 25. The total amount of carbon in forests by region in 2005 (Gt)
20

You Do the Math: 

Although elephants vary in size and 

weight, let’s say the average weight of 

an elephant is four tonnes (Figure 26).

How many elephants would it take to 

equal one Gt?

To calculate this, divide 1,000,000,000 

by 4.

How many elephants would it take to 

equal the weight of carbon in all of the 

world’s forests?

REFLECTION

SECTION

In Inquiry 2, you learned 

that more forests are being 

lost than are gained each 

year. Now read the last 

sentence on page 19. Does that sentence 

make sense in light of what you know about 

the loss of forests? Why or why not?

FAO scientists found that the amount of 

forests worldwide is declining. They also 

found the amount of carbon held by forests 

is declining. If, as most scientists believe, 

climate change is caused largely by an 

increasing amount of carbon dioxide in the 

atmosphere, what conclusion might you 

reach about the need for a greater or lesser 

amount of forest land?

Fig 26. The average elephant weighs about four tonnes
21

INQUIRY 4: HOW WELL ARE WE MANAGING 

OUR FORESTS WORLDWIDE?

THE SITUATION: As you know, forests 

provide many benefi ts to people and other 

animals. For forests to provide these benefi ts, 

however, they must be managed so that they 

remain healthy and sustainable. Although 

there are many ways to identify what makes 

forests healthy and sustainable, FAO 

selected 6 criteria (Figure 27).

Extent of forest resources

Biological diversity

Forest health and vitality

Productive functions of forests

Protective functions of forests

Socioeconomic functions of forests

Figure 27. The 6 criteria of sustainable forest 

management used by FAO

For each of the 6 criteria, FAO identifi ed 

information that served as indicators of 

sustainable forest management. Sustainable 

forest management is management that 

keeps forests healthy now and into the future. 

An indicator is a representation of something 

else. For example, when you complete a 

school assignment, you receive a grade or 

other assessment of your work. The grade 

or assessment is an indicator of your school 

achievement, but it is not the achievement 

itself. Indicators are the many ways a teacher 

has to assess how well you have done. In the 

same way, FAO identifi ed ways to measure 

how well we are doing globally to manage our 

forests. Table 2 describes the indicators of 

sustainable forest management used by FAO 

in their study, according to the 6 criteria.

Fig 28. Forests that retain their biological 

diversity are more sustainable

GLOSSARY: 

sustainable: The quality of surviving 

or being maintained over a specifi c 

time period. 

criteria: Standards on which a 

judgment or decision may be based. 

biological diversity: A measure of 

the differences between the types and 

numbers of living things in a natural 

area.

socioeconomic: Of, relating to, or 

involving a combination of social and 

economic factors.

indicator: Something that measures or 

shows something.

medicinal: Being or acting like a 

medicine.

social service: A process or service, 

usually sponsored by a government, 

that benefi ts humans.

fodder: Coarse food for cattle, horses, 

or sheep, etc., like straw or hay.
22

CRITERIA INDICATORS

Extent of forest 

resources

Area of forest in hectares.

Area of other wooded land in hectares.

Total volume of wood in all trees of a minimum size. Measured from 

the ground to a particular diameter of the trunk.

Amount of carbon in the living part of the forest in tonnes.

Biological diversity Area of primary forest in hectares.

Area of forest in hectares designated primarily for the conservation of 

biological diversity.

Total forest area in hectares, excluding area of productive forest 

plantations.

Forest health and 

vitality

Area of forest in hectares affected by fi re.

Area of forest in hectares affected by insects, diseases, and other 

disturbances.

Productive 

functions of forests

Area of forest in hectares designated primarily for production.

Area of productive forest plantations in hectares.

How much wood is produced for wood products, measured by the total 

volume of trees and how much of that volume is designated for wood 

products.

How much wood is harvested every year, measured by volume.

How much of non-wood forest products is collected or harvested each 

year, measured by volume.

Protective 

functions of forests

Area of forest identifi ed primarily for protection of soil and water in hectares.

Area of protective forest plantations in hectares.

Socioeconomic 

functions of forests

Value of total wood removed, measured in United States dollars ($).

Value of total non-wood forest products removed, measured in United 

States dollars ($).

Total employment having to do with forest production, measured in 

number of people employed.

Area of forest under private ownership measured in hectares.

Area of forest designated primarily for social services measured in 

hectares.

Table 2. Criteria and indicators of sustainable forest management used by FAO

You learned about the extent of the world’s 

forests in Inquiry 2. If forests are to be 

sustainable into the future, they must 

not continue to shrink in size. Therefore, 

the extent of the world’s forests, at the 

subregional, regional, and global levels, is a 

measure of forest sustainability. 

Biological diversity is a measure of the 

differences between the types and numbers 

REFLECTION 

SECTION

What characteristic do all of 

the indicators listed in Table 

2 have in common? Hint: 

The common characteristic 

has something to do with 

their ability to be compared across regions.
23

of living things in a natural area. For example, 

if an area has more types of plant species 

than another area, it is more biologically 

diverse in plant life. Areas that have kept their 

natural level of biological diversity are usually 

considered healthier and are better able to 

withstand threats now and into the future. 

Therefore, biological diversity is a measure of 

forest sustainability (Figure 28, page 21).

Forest health and vitality is also a measure of 

forest sustainability. This was measured by 

how much forests were negatively affected by 

fi re, diseases, or insects (Figure 29).

If a forest is productive, it provides useful 

products to people. These products include 

timber, fuelwoods, foods (fruits, mushrooms, 

bushmeat), medicinal plants, fodder, and 

other products (glossary on page 21). If a 

forest is to provide these products now and 

into the future, it must be carefully managed 

so that it remains healthy. The amount 

of land that is managed to provide forest 

products over time provides a measure of its 

productivity and its sustainability.

If a forest is managed for protective benefi ts, 

it must be safe from a range of threats 

and uses. Protective benefi ts include 

environmental benefi ts, such as clean water, 

clean air, and healthy soil. The amount 

of land being managed for these benefi ts 

over time is another measure of forest 

sustainability (Figure 30).

Forests also provide fi nancial and social 

benefi ts to people. One measure of 

sustainable forest management is the amount 

of employment provided by forests over time. 

This employment may be in or away from 

the forest. Social benefi ts include things like 

education, recreation, and inspiration. If a 

forest is managed for these benefi ts over 

time, FAO considered it to be a positive 

indicator of sustainable forest management 

(Figure 31).

Using these 6 criteria and 21 indicators 

of sustainable forest management, FAO 

scientists assessed the world’s forests by 

Figure 31. Forests that provide recreation for 

people over time are more sustainable

Figure 30. Forests managed to provide 

environmental benefi ts over time, such as clean 

water, are more sustainable

Figure 29. Forests negatively affected by fi re are 

less sustainable
24

Table 3. Trends in progress toward sustainable forest management for regions and subregions of the world

Themes and variables

 Positive change (greater than 0.5% per year)

 No major change (between -0.5% and 0.5% per year)

 Negative change (less than -0.5% per year)

- Information not available

NWFP = Non wood forest products

Africa

Asia

Europe

North and 

Central 

America

Oceania

South 

America

Eastern and 

Southern

Northern

Western and 

Central

East

South and 

Southeast

Western and 

Central

Carribbean

Central

North

Extent of forest resources

Area of forest            

Area of other wooded land           - 

Growing stock of forests           - 

Carbon stock per hectare in forest biomass         - - - 

Biological diversity

Area of primary forest            

Area of forest designated primarily for 

conservation of biological diversity           - 

Total forest area excluding area of 

productive forest plantations            

Forest health and vitality

Area of forest affected by fi re - - -      -  - 

Area of forest affected by insects, diseases 

and other disturbances - - -     - -  - 

Productive functions of forest resources

Area of forest designated primarily for 

production           - 

Area of productive forest plantations            

Commercial growing stock           - 

Total wood removals            

Total NWFP removals - - -      - - - 

Protective functions of forest resources

Area of forest designated primarily for protection           - 

Area of protective forest plantations            

Socio-economic functions

Value of total wood removals -  -    -    - 

Value of total NWFP removals -  - -     -  - 

Total employment            -

Area of forest under private ownership           - -

Area of forest designated primarily for social 

services           - 

REFLECTION 

SECTION

Think about a forest that is 

near you or that you have 

visited. Based on FAO’s 

criteria and indicators, would 

you say this forest is sustainable? Why?

region and subregion. When they were 

fi nished, they had an idea of how well 

forests are being managed so they will be 

sustainable now and into the future.
25

REFLECTION 

SECTION

Do you think it is 

important to consider 

subregions of the world 

when trying to understand 

progress toward 

sustainable forest management? 

Why or why not?

Using Table 3, consider the indicators

of forest sustainability for your own

subregion or region. For which indicator 

is your subregion or region doing well? 

What should it improve?

WHAT THEY DISCOVERED: At fi rst, FAO 

examined the information by regions. Then 

they looked at areas smaller than regions, 

called subregions. The researchers found 

that when they looked at subregions, the 

picture was sometimes different than when 

they looked at an entire region. For example, 

a national effort to plant trees in China 

showed an overall increase in forests in Asia, 

but not all subregions of Asia had an increase 

in forests. FAO wanted to know if subregions 

showed positive or negative trends in 

sustainable forest management. The 

scientists found both positive and negative 

trends across the world (Table 3, page 24). 

FAO also compared trends in forest 

management in rural areas of the world 

experiencing the highest poverty levels. They 

found a higher proportion of negative trends 

in sustainable forest management for the 

poorest rural areas of the world.

As you can see, FAO found that the answer 

to their question is not clear. In some areas, 

progress is being made. In others, progress 

is not being made. Table 3 tells whether the 

trends are positive (

), negative (), or about 

the same (

) in each region or subregion of 

the world.
26
EDUCATOR RESOURCES 27

Note to Teachers
28

The Natural Inquirer is an integrated science education journal for students aged 11-14. 

In the United States where the journal was fi rst published, the Natural Inquirer presents 

research from scientists working in the United States Department of Agriculture’s Forest 

Service. This edition of the Natural Inquirer presents the results of a worldwide effort to 

understand the world’s forests, organized by the United Nations Food and Agriculture 

Organization, or FAO. The report from which this Natural Inquirer is written is the Global 

Forest Resources Assessment 2005. It contains information from 229 countries and 

territories around the world.

You can access the FAO report at http://www.fao.org/forestry/fra2005/. 

This journal is organized into four Inquiries. Each Inquiry presents a category of fi ndings 

from the Global Forest Resources Assessment 2005. Each Inquiry builds on the previous 

inquiry’s information, and each should be considered a separate lesson. A lesson plan for 

each Inquiry follows this "Note to Teachers". The educational concepts, which immediately 

follow the "Refl ection Answer Guide", summarize suggested key learning objectives for the 

journal.

To be most effective, the Inquiries should be presented in the order outlined in the journal. 

At the beginning of the journal, three sections set the context for learning. “Welcome to 

the World’s Forest Edition of the Natural Inquirer!” provides an introduction to the journal. 

“Thinking about the Environment” presents benefi ts of forests and sets the stage for why 

it is important to understand forests at a global scale. “Thinking about Science” presents 

the method used by FAO to gather the information presented in the Inquiries. To be most 

effective, students should read these sections before they begin the Inquiries. A short 

lesson plan for these sections is presented on page 29.

Each Inquiry is comprised of 2 main sections: "The Situation" and "What They 

Discovered." "The Situation" introduces the question asked by FAO. This section also 

presents background information that leads to the research question. Whenever there is 

a scientifi c question to be answered, there is a situation that led to the development of the 

question.

"What They Discovered" presents the answer to the research question. This section 

includes tables and photographs as well as text. Embedded within this section are 

“Refl ection Sections,” which ask questions aimed at encouraging students to think 

critically about what they are reading. You may use these questions to check student 

comprehension. In some instances, a "You Do the Math" section provides an opportunity 

for students to integrate math with their scientifi c learning. 

Before beginning any of the Inquiries, have your students read "Welcome to the World’s 

Forests Edition of the Natural Inquirer! " This section introduces the journal and provides 

opportunity for students to begin thinking about the world’s forests within their own 

subregion, region, and as a part of the global landscape. Students should only have to 

read this section once. Before they leave this section, have them locate their own region 

and subregion of the world.

EDUCATOR RESOURCES

Note to Teachers
29

Lesson Plan Welcome to the World’s Forests Edition 

of the Natural Inquirer!

Lesson Plan for Thinking About the Environment

Lesson Plan for Thinking About Science

Lesson Plan for Introduction to the Inquiries

Have your students read the fi rst paragraph. 

(When students read this journal, they may 

read silently or you may select students 

to read paragraphs out loud.) Next, have 

students “do the math” and give the answer. 

(In 2008, the UN was 63 years old.)

Students should then read the next 

paragraph. Then hold a discussion about the 

meaning of the word “improve.” What does 

it mean to them? What might improvement 

mean to a country in transition and 

modernization?

Students should read the next paragraph. 

Ask them to identify the main idea of the 

paragraph. 

The next paragraph begins with “Trees 

are often planted...” Have students read 

this paragraph and follow up with a class 

discussion. Questions to get you started: 

“How is your life improved by forests?” “What 

do you think is the topic of this journal?”

Examine Figure 1. Has anyone seen a forest 

plantation? Have them tell about it.

Have students read the next paragraph in 

preparation for examining Figure 2. Have 

them locate their region and if appropriate, 

their subregion.

Have students read the fi rst paragraph. 

Questions to generate discussion include: 

“What is the main idea of the paragraph?” 

“Who or what benefi ts from forests?”

Examine Figure 3. What does the photograph 

show?

Now do the Refl ection Section on page 7. 

Students may read silently and write a list of 

benefi ts. Their lists should be shared with the 

class, where a master list can be created. As 

your class reads through the journal, add to 

the list of benefi ts. 

Read fi rst the paragraph. Ask students to 

think of a time in the last 3 days when they 

collected information. This can be numeric or 

non-numeric. Challenge students to think of 

numeric data recently collected. For example, 

they may have checked the temperature, 

the cost of something, or the distance to a 

location.

Read the next paragraph. Check for student 

comprehension by asking questions about 

using a standardized unit of measurement. 

(When you come to an italicized word, check 

to make sure all students understand its 

meaning). 

The following 2 paragraphs will also explain 

standardized units of measurement. After 

students read the paragraph, ask someone to 

explain the main idea of the paragraphs.

The fi nal paragraph in this section introduces 

country correspondents. After students read 

this paragraph, have them clarify the role of 

the country correspondent in relation to FAO 

scientists.

Have students read this entire section 

silently. After they have fi nished, check 

comprehension by asking them if the 

correspondents used the same unit of 

measurement as FAO. If students understand 

the term, they will know that the same unit of 

measurement was either necessary, or FAO 

had to be able to transform any data received 

into a standardized unit of measure. 
30

Before beginning Inquiry 1, have students 

read "Thinking About the Environment" and 

"Thinking About Science". This will give 

students an introduction to the importance 

of global forests and to FAO’s effort to 

understand the world’s forests.

Need: Journal, paper, pencils, a globe or world 

map with lines of latitude, internet or library 

access, and copy of the Table on page 31.

Have students read the title and fi rst paragraph 

of "The Situation". Check comprehension 

by asking the difference between weather 

and climate. Ask students to identify the two 

ways that FAO could have classifi ed forests, 

based on the information in this paragraph. 

Check comprehension of the word classify. It 

is important for students to fully understand 

classifi cation before continuing.

Have students read and answer the question 

in the next paragraph. 

After reading the paragraph that follows, have 

students examine Figures 6 and 7. Explain 

latitude, especially as it relates to the equator 

and Earth’s climate. Now do the activity 

below to determine your latitude

DETERMINING LATITUDE.

Using a globe or a world map, have students 

identify where on Earth they are located. 

Primarily, have them identify their latitude, 

or distance from the equator. Some maps 

may show latitude in degrees, minutes, and 

seconds. Others may only show degrees 

and minutes, or just degrees. Have them 

identify the closest degree of latitude to their 

geographic location. After they have located 

their latitude, determine how far between the 

equator and one of the poles their location 

is. (Latitude is 0 degrees at the equator, 90 

degrees at the poles.)

Students should read the paragraph that 

begins, “About 71 percent of Earth....”. After 

reading the paragraph, they should examine 

Figure 8.

Lesson Plan for Inquiry 1

After reading the next paragraph, ask 

students to identify the paragraph’s main 

idea. Then, ask them to describe the natural 

area close by. How much rainfall does it 

receive? Ask students to describe the trees 

and vegetation growing close to home.

Students should read the next paragraph, 

then examine Figures 9, 10 and 12. 

Next, have students do research in the library 

or on the internet to discover their elevation 

and amount of annual rainfall. Elevation is 

the height of the land above sea level. Using 

Figures 9, 10 and 12, have them identify what 

kind of forest, if any, should naturally grow 

nearby.

Using the picture of the distribution of the 

world's forests on page 13, you can further 

check the understanding of the students by 

asking them to explain why they think that 

there are no forests in North Africa.

Now, using Figure 5, have students identify 

into which ecozone forests close to home 

should be placed. 

Read the paragraph beginning with “In 

addition to latitude,...” Hold a class discussion 

based on the last sentence in the paragraph. 

Then read the next paragraph.

Using Table 1, hold a class discussion on 

the closest forest to their home. Into which 

FAO category would they place this forest? 

Explore the advantages and disadvantages 

of each forest type. Students can work in 

small groups to do this. Do plantation forests 

look different than more natural forests? 

How? Do students think different animals 

might live in different types of forests? Why 

or why not? What evidence do they have to 

support their answer?

The next four paragraphs should be read by 

students, and a short class discussion should 

be held between each paragraph. This will 
31

bring students to the end of The Situation. 

Some ideas for discussion include:

Paragraph 1: How many of the 5 

categories contain trees 

planted by humans? Is this a 

surprise? Why or why not?

Paragraph 2: Do you think fruit orchards 

should have been included 

by FAO in their study? 

Why or why not?

Paragraph 3: Discuss the difference 

between primary forests 

and protective plantations.

Paragraph 4: Discuss the idea of 

understanding trends and 

examining trend data. 

WHAT THEY DISCOVERED

Read the entire section. Use your globe, a 

world map, or Figure 2 to locate the Amazon 

area of South America. Read the next 

paragraph and examine Figures 11 and 13. Ask 

students to identify which category of forest is 

comprised of the least amount of land.

Have them “do the math (fi rst problem 

only).” Students can use Figure 11 to do this 

calculation. Ask a student to explain what this 

means about the current character of most of 

the world’s forests. 

Have students “do the math” (second 

problem) and briefl y discuss the meaning of 

the results.

REFLECTION SECTION:

In small groups, have students discuss the 

two "questions" and appoint a representative 

to make a short presentation to the class. 

You can use this presentation as an informal 

assessment of student comprehension. 

EXTENSION: 

Kenya’s Green Belt Movement (www.

greenbeltmovement.org) has developed a 

program to reforest Kenya. The program 

suggests what types of trees should be 

planted for what purposes and where. Using 

the Table below (developed by the Green Belt 

Movement), have students identify into which 

of FAO’s 5 categories of forests each type of 

planting should be placed. 

Remember that in every case and in the 

Table below, humans are planting trees. 

Therefore, none will be categorized as 

primary forest or modifi ed natural forest. 

PURPOSE BEST SUITED 

SPECIES

PRIMARILY 

PLANTED IN FAO CATEGORY

Environmental 

conservation

Native Public places

Household needs Fast growing

non-native

Farms

Fodder Fast growing 

non-native

Farms

Medicine/herbs Native Public places

Food security Non-natives and fruit 

trees

Farms

Shade Native Farms

Increase biological 

diversity

Native 

(to support birds, 

animals, and plants)

Public places

Protecting cultural 

sites

Native Public places
32

Before beginning Inquiry 2, have students 

read "Thinking About the Environment" and 

"Thinking About Science" if they have not yet 

done so. These sections will give students 

an introduction to the importance of global 

forests and to FAO’s effort to understand the 

world’s forests.

Need: Journal, pencils, paper, copy of the 

Table below.

Read paragraph 1. Ask students: What is the 

main idea from this paragraph? (The main 

idea is that we have not yet learned whether 

forests are growing or shrinking in size 

worldwide.)

Read paragraph 2. Hold a class discussion 

about the idea of renewable resources. Here 

are some questions to get the discussion 

started. “What are renewable resources, 

and what makes forests renewable?” “What 

are some other renewable resources?” 

“What are some non-renewable resources?” 

“What is the advantage of using renewable 

resources?”

Examine Figure 14. Ask if any students have 

planted trees. If so, ask them to share their 

experiences.

Lesson Plan for Inquiry 2

Have a student read the next paragraph, 

beginning with "FAO wanted to know..." Then 

hold a class discussion using the Refl ection 

Section. This may also be done in small 

groups.

Ask students to read the fi rst 2 paragraphs in

"What They Discovered" and examine Figure 

15. Using the Table below, have students 

calculate the amount of forest per person for 

each region. Have students compare their 

region with other regions. Order the regions 

from the most forest per person to least forest 

per person.

Now hold a class discussion based on these 

questions:

1. Where is my region on the list? Is it 

near the top or bottom, or near the 

middle?

2. How does my region compare with 

other regions in the world?

3. What are some of the reasons my 

region is ranked where it is on the 

list?

4. How might the country I live in 

compare with my region as a whole? 

(If you have access to the internet, 

visit and download the FRA 2005 

Global Tables in excel from the main 

REGION POPULATION 

(2004)

FOREST AREA 

(HECTARES)

AMOUNT OF 

FOREST PER 

PERSON

Africa 868 182 000 635 412 000

Asia 3 837 943 000 571 577 000

Europe 723 495 000 1 001 394 000

North and Central 

America 508 064 000 705 849 000

Oceania 32 764 000 206 254 000

South America 364 668 000 831 540 000
33

page. Table 1 contains population 

Figures and Table 3 the area of 

forest. Using these resources, your 

students can calculate an estimated 

amount of forest per person for any 

country included in the report.)

Have students read the remaining 

paragraphs and examine Figure 17. After 

examining Figure 17, have your students 

look at Figures 18, 19, 20 and 21. You may 

have to explain these maps to your students. 

For more information about these maps, visit 

http://www.worldmapper.org/about.html.

Have them “do the math” to determine how 

many fewer hectares are being lost now than 

in the past. Hold a class discussion about 

these numbers. What do they tell us? Is this 

good news? Why or why not? (Students 

may break into small groups for these 

discussions.)

Have students read the last paragraph and

examine fi gures 17, 20 and 21 and answer 

the questions. (Refer to page 37 for 

answers). Hold a class discussion based 

on the refl ection questions. Here are some 

additional questions to get the discussion 

started:

1. What is happening in our region or 

subregion that is leading to the loss 

or gain of forests? 

2. Do you think this trend might change 

in the future? Why or why not?

3. What might happen to cause a 

change in the trend?

Hold small group discussions about whether 

your current regional or subregional trend is 

desirable or should be changed. Remember 

that not all deforestaion is bad. Some forests 

may have to be converted to agriculture to 

provide enough food or to provide land for 

roads, houses and ports. In these groups, 

have students identify 3 advantages and 

disadvantages to the current trend. Have each 

group develop 2 action items that will either 

support or try to change the trend. Each group 

will identify a spokesperson to present their 

action items and rationale to the class. 

As a class, identify any action items that can 

be taken by the students.

EXTENSION: The Green Belt Movement

Using the internet, visit:

http://www.greenbeltmovement.org. 

Have students research this site and others 

to discover how one African woman has 

made a difference by planting trees. If 

possible, explore options for planting trees 

near your school or in your community. 
34

Before beginning Inquiry 3, have students 

read "Thinking About the Environment" 

and "Thinking About Science" if they have 

not yet done so. This will give students an 

introduction to the importance of global 

forests and to FAO’s effort to understand the 

world’s forests.

Need: Journal, pencils, and paper.

Have students read the fi rst paragraph 

and ask them to study the carbon cycle 

(Figure 22). Discuss the carbon cycle in 

your classroom. Before moving forward, 

make certain your students understand that 

all living things contain carbon, and that 

carbon moves from the atmosphere, through 

living matter, into the soil and water, and is 

released again into the atmosphere. 

Ask students to read the next paragraph.

Ask them to identify the main idea of the 

paragraph. 

Now have them read the next paragraph 

(beginning with "From Figure 22") and 

examine Figures 23 and 24. Ask students 

if they can guess why FAO wanted to 

estimate the amount of carbon held by the 

world’s forests. To do this, your students 

must connect information from the previous 

paragraphs. The logical conclusion should 

be that forests absorb and hold carbon, and 

therefore may help address climate change.

Have students read the next paragraph. That 

paragraph should confi rm the conclusion 

made in the previous exercise.

Have students read the next paragraph 

beginning with "Scientists believe...". Check 

their understanding by emphasizing that 

after all water is removed from a tree’s living 

parts, about half of the remaining weight is 

carbon. Ask students if they think humans 

have carbon in them as well. (This question 

will allow you to check their comprehension.) 

About 18 percent of a human body is carbon. 

Remind your students that carbon is the most 

abundant element on Earth, because all living 

Lesson Plan for Inquiry 3

things contain carbon. 

Using the Refl ection Section on page 18, hold 

a class discussion about the evidence for 

climate change. Students may have differing 

opinions on this, and they should examine 

their own reasons for believing as they 

do. What evidence are they using? Is that 

evidence credible? How do they know?

Have students read all paragraphs in "What 

They Discovered" and look at Figure 25. Ask 

them if they can guess what "biomass" is. For 

the purposes of this graph, biomass is the 

living material of trees. (Biomass usually refers 

to living and once-living material.) Ask students 

if they can guess why South America has 

more carbon in biomass than other regions 

of the world. (South America contains a large 

area of rain forest, which contains a

massive amount of leafy green biomass).

Now have students “do the math.” 

Considering how many elephants it would 

take to equal the amount of carbon in the 

world’s forests, ask them if they think there 

is more carbon in plant or in animals on 

Earth. Earth’s human population is almost 7 

billion, but your students must consider that 

other animals live on Earth as well. (After 

comparing the numbers and considering 

the size of other animals, students should 

conclude that worldwide, plants must contain 

more carbon than animals.)

Now ask students to consider the refl ection 

questions. This may be done in small groups. 

For the fi rst question, students should 

conclude that the two pieces of information 

are compatible. That is, as more forest land 

is lost than is gained, it makes sense that the 

amount of carbon in the world’s forest should 

be declining. Ask students to discuss the 

second question in small groups and report 

their conclusion to the class.

Based on this Inquiry, students should identify 

the holding of carbon as another benefi t of 

forests. This benefi t should be added to the 

classroom list of forest benefi ts.
35

Before beginning Inquiry 4, have students 

read "Thinking About the Environment" 

and "Thinking About Science" if they have 

not yet done so. This will give students an 

introduction to the importance of global 

forests and to FAO’s effort to understand the 

world’s forests.

Need: Journal, pencils, paper.

Have students read the fi rst sentence under 

"The Situation". Have them read the defi nition 

of sustainable. Hold a class discussion about 

what sustainability means. Some ideas you 

can use include:

1. Have students brainstorm words, 

phrases, or concepts that mean 

sustainability to them. This could be 

things like regular meals, going to 

school, being a member of a family, 

etc. 

2. Now challenge students to think 

about environmental sustainability. 

What does environmental 

sustainability mean to them? 

3. Have students review the defi nition 

of criteria. Make certain students 

understand what criteria means 

before continuing.

4. Examine Figure 27. Have students 

guess what each of these terms 

might mean. 

Now have students read the paragraph 

following Figure 27. Discuss the term 

“indicator” with them. In small groups, 

have students identify 3 criteria and two 

indicators for each criteria. The criteria can 

be something from their own life. Examples 

of criteria might include maturity, human 

intelligence, good farming weather, etc. For 

each of the criteria identifi ed, ask students to 

identify 2 indicators that can be measured. 

Measurable indicators are ones to which you 

can apply a specifi c number and a unit of 

measurement. 

Lesson Plan for Inquiry 4

Before continuing, make certain students 

understand what criteria and indicators are. 

Have students examine Table 2 (page 

22) and answer the refl ection question.

Then, ask students if any of the indicators 

are not measurable. Ask students to think 

about whether FAO researchers could 

determine how sustainable the world’s forest 

management is today if the indicators were 

not measurable. Hold a discussion about 

measurement in science. Although most 

science is based on measurement, not all 

scientifi c studies use measured evidence. At 

the scale of the planet, or even regionally and 

subregionally, however, it would be diffi cult 

to determine sustainability without consistent 

measurement. 

Have students break into 6 small groups. 

Assign one of the next 6 paragraphs to each 

group. Each of these paragraphs describes 

in more detail one of the FAO’s criteria for 

sustainability. Each group will read and 

discuss their paragraph, then explain the 

criteria to the class. The fi rst paragraph 

begins with “You learned about the extent...” 

The last of the six paragraphs begins with 

“Forests also provide fi nancial...” As an 

extension, students may use the internet or 

library to do additional research about their 

criteria. For the criterion on forest health, 

note that not all forest fi res are negative. 

Some forest types, for example, depend on 

occasional fi re to remain healthy. Emphasize 

that this criterion is focused on threats to 

forest health, not on all forest fi res.

Read the next paragraph ("Using these 6 

criteria..."). Ask students if they agree with 

the FAO’s criteria for sustainable forest 

management. Ask students to contribute 

any additional criteria for sustainable forest 

management.

Have students complete the refl ection 

question on page 24. You may do this as a 

class, or use the six small groups from the 
36

previous exercise. If there are no forests 

nearby, select a forest type with familiar 

characteristics.

Have students read the fi rst paragraph after 

What They Discovered. Students should 

refer to Table 3 on page 24. Ask students if, 

based on what they have read so far, they are 

surprised that scientists found both positive 

and negative trends across the world. Why or 

why not?

Read the next paragraph. Hold a class 

discussion about rural poverty and forest 

sustainability. 

Discuss the implications of this fi nding. 

Have students read the remainder of the 

article, including an examination of Table 3. 

Using Table 3, have students identify their 

own region or subregion (if applicable). Have 

them look down the column at the indicators 

for their region or subregion. In small groups, 

have students develop a method to compare 

columns. Have each group share their 

assessment with the class. 

Hold a discussion about forest sustainability 

in their region or subregion. Include the 

refl ection questions in the discussion. Does 

their analysis suggest that something needs 

to be done? If so, discuss options for action. 

Are there any actions that individual students 

or the class can take?

EXTENSION: If the class has identifi ed any 

actions that can be taken, give students 

time to plan and implement their action. 

For example, they might write letters to the 

government in support of reforestation. They 

might decide to plant trees in their community. 

They might start a Green Belt Movement in 

their community. Any action taken should 

be carefully considered for its practicality, 

keeping available resources in mind. 
37

Note: The refl ection questions are meant to 

encourage students to think critically about 

what they have read. There are no right or 

wrong answers.

THINKING ABOUT THE ENVIRONMENT

What are some of the benefi ts forests provide 

to your community? 

Students should answer this based on their 

own experience. Students may do this in 

groups or individually, or you may hold a 

class discussion. Students should think 

not only of nearby forests, but should also 

consider the benefi ts gained from forests 

more distantly located from the community.

INQUIRY 1

Describe the majority of forests worldwide. 

You can either use one or two categories to 

do this. 

Just over half of forests worldwide are 

modifi ed natural forests. These forests have 

native trees that have grown naturally. There 

is evidence of human activity in these forests, 

even though they have native trees that 

have grown naturally. A little over one-third of 

forests worldwide are primary forests. These 

forests also have native trees that have 

grown naturally and there is no visible sign 

of human activity in these forests. Therefore, 

over 80 percent of forests worldwide are 

made up of native trees that have grown 

naturally, and most of these forests show 

signs of human activity.

What are two major trends in the categories 

of forests? 

The amount of forest with naturally-growing 

native trees is decreasing. The amount of 

forest worldwide that has been planted by 

humans is increasing. 

INQUIRY 2

Do you think FAO found that Earth is gaining, 

losing, or keeping about the same amount of 

forests over time? 

This question can be discussed as a class or 

in small groups. Whatever answer students 

Refl ection Answer Guide

give, they should be able to back up their 

answer with logically-constructed arguments 

for why they answered as they did. 

If more forests are lost than are being 

planted, what will happen to the benefi ts 

provided by forests? 

The amount of benefi t provided by forests will 

be reduced.

Why is it important to understand whether the 

amount of forest land world wide is shrinking, 

growing, or staying about the same? 

Because forests provide benefi ts to people 

and other living beings. If we know that 

forests are shrinking in size worldwide, we 

can take action to stop that trend.

Look at Figure 17. Find the region and 

subregion where your home is located. How 

does your region or subregion compare with 

the rest of the world? Why do you think that is?

This must be answered individually by each 

classroom, group of students, or individual 

student. When giving reasons, the student 

should be able to support his or her claim 

with logical thinking.

Now compare cartograms 20 and 21 with 

the blue and green bars in Figure 17. What 

do Figures 17, 20 and 21 tell you about the 

forests in Asia?

Figure 17 shows that Asia lost forests from 

1990-2000 (blue bars) but gained forests 

from 2000-2005 (green bars). This Figure 

doesn't say in which countries these changes 

have occurred. Cartograms 20 and 21 show 

that the greatest increase in forests has 

occurred in China, while many other countries 

in Asia are still losing forests.

INQUIRY 3

Refl ection Section: Do you think Earth’s 

climate could be changing due to human 

activity? Why or why not? 

Students should be aware that the burning of 

fossil fuels by humans is causing the amount 

of carbon dioxide in the atmosphere to rise. 
38

This rise in carbon dioxide is believed to be 

one of the major causes of global climate 

change. While most scientists believe this to 

be the case, some people believe the recent 

changes in weather patterns are not caused 

by an increase in carbon dioxide. Therefore, 

students should state what they think and be 

able to support their claim with a logicallyconstructed argument.

In Inquiry 2, you learned that more forests are 

being lost than are gained each year. 

Now re-read the last sentence on page 19. 

Does that sentence make sense in light of 

what you know about the loss of forests? 

Why or why not? 

It should make sense to students that if the 

amount of forests worldwide is decreasing, 

the amount of carbon held in the world’s 

forests would be declining as well.

FAO scientists found that the amount of 

forests worldwide is declining. They also 

found the amount of carbon held by forests 

is declining. If, as most scientists believe, 

climate change is caused largely by an 

increasing amount of carbon dioxide in the 

atmosphere, what conclusion might you 

reach about the need for a greater or lesser 

amount of forest land? 

Students should recognize that trees 

and forests play a role in holding carbon 

on Earth and keeping some of it out of 

the atmosphere. They should conclude, 

therefore, that if would be wise to protect our 

current forests and if possible, increase the 

amount of forests.

INQUIRY 4

What characteristic do all of the indicators 

listed in Table 2 have in common? Hint: The 

common characteristic has something to 

do with their ability to be compared across 

regions. 

They can all be measured.

Think about a forest that is near you or that 

you have visited. Based on FAO’s criteria 

and indicators, would you say that forest is 

sustainable? 

This is an individual question and must be 

answered individually. Students should be 

able to support their answer with logical 

reasons.

Do you think it is important to consider 

subregions of the world when trying to 

understand progress toward sustainable 

forest management? Why or why not? 

This question can be answered individually, 

within a small group, or in a class discussion. 

Students should be able to support their 

answer with logic. Since subregions are 

smaller and more homogeneus than 

regions in general, students should realize 

the importance of examining sustainable 

management at a subregional level.

Using Table 3, consider the indicators of 

forest sustainability for your own subregion or 

region. For which is your subregion or region 

doing well? What should it improve? 

This answer will depend on the geographic 

location of the student.
39

Educational Concepts Addressed by the Inquiries

Note: These educational concepts have been 

adapted from the North American Association 

for Environmental Education’s Excellence in 

Environmental Education: Guidelines for Learning,

and focus on learning by students aged 11-14.

Inquiry Skills:

Questioning Skills

Learners are able to identify, develop, or explain 

inquiry questions based on personal experience, 

discussion, or reading.

Learners are able to summarize environmental 

problems or situations based on personal 

experience, discussion, or reading.

Data Collection Skills

Learners are able to understand and/or use 

measurement tools or metrics.

Learners are able to choose and synthesize 

materials from second-hand sources, such as 

books, journals, newspapers, and the internet.

Data Organization Skills

Learners are able to read and explain data 

summarized in tables, charts, graphs, or maps. 

Learners are able to draw conclusions and 

develop explanations based on data or 

information.

Learners are able to distinguish between 

description and explanation.

Learners are able to propose explanations and 

evaluate the strengths and weaknesses of these 

explanations.

Learners are able to compare and contrast data 

representing different geographic locations.

Knowledge of Earth Systems and 

Processes:

Earth As a Physical System

Learners understand and are able to describe 

the following physical Earth processes:

- global carbon cycling

- carbon cycling in trees

- climate change (its cause and potential effects)

- latitude and its relation to tree species

- elevation and its relation to tree species.

Environment and Society:

Human/Environment Interactions

Learners understand and can explain how 

human-caused changes to forests have 

consequences: immediately and in the future,

and locally, regionally, and globally.

Natural Resources (forests)

Learners understand that natural resources (forests) 

are unevenly distributed across the planet.

Learners understand and can describe the 

multiple benefi ts offered by forests.

Learners understand that forests can change 

because of natural and man-made activity.

Learners understand that a variety of forests 

exist on Earth, and this variety may be created 

naturally or may be man-made.

Technology

Learners understand the increasing human 

ability to shape and control the environment 

as a function of the development and use of 

technology. 

Environmental Issues

Learners understand that environmental issues 

occur at all scales, and that people in other 

places in the world experience environmental 

issues similar to the ones they are concerned 

about locally.

Skills for Understanding and Addressing 

Environmental Issues:

Understanding and Addressing 

Environmental Issues

Learners are able to apply their knowledge of 

ecological and human processes and systems 

to identify the consequences of specifi c 

environmental issues.

Learners understand the nature of trade-offs, 

and are able to analyze the risks and benefi ts 

of human environmental actions.

Learners are able to predict the consequences 

of inaction or failure to resolve an 

environmental issue.

Learners are able to identify and evaluate 

solutions and courses of action to address 

environmental issues.

Decision-making and Citizenship Skills

Learners are able to identify, justify, and clarify 

their views on environmental issues.

Learners are able to evaluate the need for 

citizen action and decide whether they should 

or could be involved.

Learners are able to set realistic goals for action.
40

WHAT DOES FAO DO?

FAO’s Member Nations have given the Organization the task of helping them create a world 

where no one goes hungry.

So what exactly is FAO doing to help build a world without hunger? Its work can be divided 

into four main activities: 

Information

First and foremost, the world needs reliable information about how many people are hungry, 

who they are and where they live. To help bring an end to hunger, countries need to have 

up-to-date and trustworthy information about all sorts of things: food production, prices and 

trade, land use, nutrition levels, food aid and population. FAO is the world’s leading source for 

this sort of information and has been so for more than 50 years. 

Find out more about how FAO provides the world with information (http://www.fao.org/kids/en/

information.html). 

Advice

Having mountains of information is essential. But you also need to know how to make sense 

of all this data to put it to practical use. When governments request assistance, FAO’s 

experts offer advice on how to establish policies on agriculture, forestry, fi sheries and rural 

development that can truly benefi t the hungry. 

A meeting place

Individual countries working on their own can’t bring an end to world hunger. It’s a global 

problem that requires international cooperation on many issues, including agriculture, 

fi sheries, forestry, trade and the environment. FAO provides the common ground where rich 

and poor countries can come together to reach international agreements that can help the 

world’s hungry. 

Field work

FAO also helps countries bring technical knowledge and expertise directly to farmers to 

the fi eld. The Organization coordinates thousands of fi eld projects throughout the world. It 

mobilizes and manages millions of dollars provided by industrialized countries, development 

banks and other sources to make sure these projects are effective. 

A great many of these projects are carried out in response to humanitarian emergencies 

arising from natural disasters or armed confl ict. Find out more about FAO’s work in 

emergencies (http://www.fao.org/kids/en/emergencies.html). 

A broad range of expertise

To get an idea of some of the specifi c topics that FAO deals with, visit the links below. We 

guarantee you’ll come across some surprises. 

Forestry http://www.fao.org/kids/en/forestry.html 

Fisheries http://www.fao.org/kids/en/fi sheries.html 

Food forever http://www.fao.org/kids/en/forever.htm

Emergencies http://www.fao.org/kids/en/emergencies.html

Clean energy http://www.fao.org/kids/en/energy.html

Social justice http://www.fao.org/kids/en/socialjustice.html

AIDS http://www.fao.org/kids/en/aids.html

Global warming http://www.fao.org/kids/en/gw.html

Poverty http://www.fao.org/kids/en/poverty.html

Globalization http://www.fao.org/kids/en/globalization.html

Food safety http://www.fao.org/kids/en/safety.html

 http://www.fao.org/kids/en/
41

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EDITORIAL REVIEW BOARD

The Natural Inquirer Editorial Review Board is made up of students between the ages of 

12 and 13. The Editorial Review Board reads an early copy of the Natural Inquirer and 

makes suggestions for improvement. This is Mrs Ashley Potter's 7th grade Science class, 

Morgan County Middle School, Madison, Georgia, USA.