natural resources lands

Lands
NATURAL RESOURCES
NATURAL RESOURCES
Agriculture
Animals
Energy
Forests
Lands
Minerals
Plants
Water and Atmosphere
LANDS
Taming the Wilds
Julie Kerr Casper, Ph.D.
Lands
Copyright © 2007 by Julie Kerr Casper, Ph.D.
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r
etrieval systems, without permission in writing from the publisher. For information contact:
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Library of Congress Cataloging-in-Publication Data
Casper, Julie Kerr.
Lands : taming the wilds / Julie Kerr Casper.
p. cm (Natural resources)
Includes bibliographical references and index.
ISBN-10: 0-8160-6356-7 (hardcover)

ISBN-13: 978-0-8160-6356-7
1. Land use-Environmental aspects-Juvenile literature. I. Title. II. Series.
HD108.3.C37 2007
333.73-dc22 2006037262
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Concepts of Land Resources
The History of Land Use
Renewable and Nonrenewable Resources
The Development of Land Resources
Multiple Uses of the Land
The Importance of Land Resources
Management of Land Resources
Conservation of Land Resources
Conclusion: Future Issues and
Sustainable Resources
Appendix
Glossary

Further Reading
Index
1
2
3
4
5
6
7
8
9
Contents
Preface
Acknowledgments
Introduction
vi
x
xi
1
3
0
55
73
100
121
139
166

186
199

201
215
218
T
he Earth has been blessed with an abundant supply of natural
resources. Natural resources are those elements that exist on
the planet for the use and benefit of all living things. Scientists
commonly divide them down into distinct groups for the purposes of
studying them. These groups include agricultural resources, plants,
animals, energy sources, landscapes, forests, minerals, and water and
atmospheric resources.
One thing we humans have learned is that many of the important
resources we have come to depend on are not renewable. Nonrenewable
means that once a resource is depleted it is gone forever. The fossil
fuel that gasoline is produced from is an example of a nonrenewable
resource. There is only a finite supply, and once it is used up, that is the
end of it.
While living things such as animals are typically considered renew-
able resources, meaning they can potentially be replenished, animals
hunted to extinction become nonrenewable resources. As we know
from past evidence, the extinctions of the dinosaurs, the woolly mam-
moth, and the saber-toothed tiger were complete. Sometimes, extinc-
tions like this may be caused by natural factors, such as climate change,
Preface
Natural Resources:
Priceless Gifts from the Earth
Mankind did not weave the web of life.
We are but one strand in it. Whatever we
do to the web, we do to ourselves . . .
All things are bound together.

—Chief Seattle
vi
drought, or flood, but many extinctions are caused by the activities of
humans.
Overhunting caused the extinction of the passenger pigeon, which
was once plentiful throughout North America. The bald eagle was
hunted to the brink of extinction before it became a protected species,
and African elephants are currently threatened with extinction because
they are still being hunted for their ivory tusks. Overhunting is only
one potential threat, though. Humans are also responsible for habitat
loss. When humans change land use and convert an animal’s habitat
to a city, this destroys the animal’s living space and food sources and
promotes its endangerment.
Plants can also be endangered or become extinct. An important
issue facing us today is the destruction of the Earth’s tropical rain
forests. Scientists believe there may be medicinal value in many plant
species that have not been discovered yet. Therefore, destroying a plant
species could be destroying a medical benefit for the future.
Because of human impact and influence all around the Earth, it
is important to understand our natural resources, protect them, use
them wisely, and plan for future generations. The environment—land,
soil, water, plants, minerals, and animals—is a marvelously complex
and dynamic system that often changes in ways too subtle to perceive.
Today, we have enlarged our vision of the landscape with which we
interact. Farmers manage larger units of land, which makes their job
more complex. People travel greater distances more frequently. Even
when they stay at home, they experience and affect a larger share of the
world through electronic communications and economic activities—
and natural resources have made these advancements possible.
The pace of change in our society has accelerated as well. New

technologies are always being developed. Many people no longer spend
all their time focused in one place or using things in traditional ways.
People now move from one place to another and are constantly devel-
oping and using new and different resources.
A sustainable society requires a sustainable environment. Because
of this, we must think of natural resources in new ways. Today, more
vii
PREFACE
than ever, we must dedicate our efforts to conserve the land. We still live
in a beautiful, largely natural world, but that world is quickly changing.
World population growth and our desire to live comfortably are exert-
ing pressures on our soil, air, water, and other natural resources. As we
destroy and fragment natural habitats, we continue to push nonhuman
life into ever-smaller pockets. Today, we run the risk of those places
becoming isolated islands on a domesticated landscape.
In order to be responsible caretakers of the planet, it is important to
realize that we humans have a partnership with the Earth and the other
life that shares the planet with us. This series presents a refreshing and
informative way to view the Earth’s natural resources. Agriculture: The
Food We Grow and Animals We Raise looks at agricultural resources to
see how responsible conservation, such as caring for the soil, will give
us continued food to feed growing populations. Plants: Life From the
Earth examines the multitude of plants that exist and the role they play
in biodiversity. The use of plants in medicines and in other products
that people use every day is also covered.
In Animals: Creatures That Roam the Planet, the series focuses on
the diverse species of animals that live on the planet, including the
important roles they have played in the advancement of civilization.
This book in the series also looks at habitat destruction, exotic species,
animals that are considered in danger of extinction, and how people

can help to keep the environment intact.
Next, in Energy: Powering the Past, Present, and Future, the series
explores the Earth’s energy resources—such as renewable power from
water, ocean energy, solar energy, wind energy, and biofuels; and non-
renewable sources from oil shale, tar sands, and fossil fuels. In addi-
tion, the future of energy and high-tech inventions on the horizon are
also explored.
In Lands: Taming the Wilds, the series addresses the land and how
civilizations have been able to tame deserts, mountains, Arctic regions,
forests, wetlands, and floodplains. The effects that our actions can
have on the landscape for years to come are also explored. In Forests:
More Than Just Trees, the series examines the Earth’s forested areas and
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viii
PREFACE
how unique and important these areas are to medicine, construction,
recreation, and commercial products. The effects of deforestation, pest
outbreaks, and wildfires—and how these can impact people for genera-
tions to come—are also addressed.
In Minerals: Gifts From the Earth, the bounty of minerals in the
Earth and the discoveries scientists have made about them are exam-
ined. Moreover, this book in the series gives an overview of the critical
part minerals play in many common activities and how they affect our
lives every day.
Finally, in Water and Atmosphere: The Lifeblood of Natural Systems,
the series looks at water and atmospheric resources to find out just how
these resources are the lifeblood of the natural system—from drinking
water, food production, and nutrient storage to recreational values.
Drought, sea-level rise, soil management, coastal development, the
effects of air and water pollution, and deep-sea exploration and what it

holds for the future are also explored.
The reader will learn the wisdom of recycling, reducing, and reus-
ing our natural resources, as well as discover many simple things that
can be done to protect the environment. Practical approaches such as
not leaving the water running while brushing your teeth, turning the
lights off when leaving a room, using reusable cloth bags to transport
groceries, building a backyard wildlife refuge, planting a tree, form-
ing a carpool, or starting a local neighborhood recycling program are
all explored.
Everybody is somebody’s neighbor, and shared responsibility is
the key to a healthy environment. The cheapest—and most effective—
conservation comes from working with nature. This series presents
things that people can do for the environment now and the important
role we all can play for the future. As a wise Native-American saying
goes, “We do not inherit the Earth from our ancestors—we borrow it
from our children.”
ix
W
hile we deal with different aspects of the land every day,
most people are not aware of just how much we depend on
the land and its natural resources. We depend on the land
as a source of many services—some obvious, others not so obvious.
Obvious uses are to grow food on, to graze our animals on, and for the
necessary building materials to construct our roads and homes with.
Other, more subtle, values are the aesthetic characteristics enjoyed
every time someone sets foot outside to enjoy nature, hike, camp, fish,
or participate in any form of outdoor recreation.
I hope to instill in you—the reader—an understanding and appre-
ciation of the land and its vital role in our environment. Perhaps mak-
ing you more aware of the land and all that it does for each one of us

every day will plant in you the seeds of conservation toward this pre-
cious resource and encourage environmental awareness and the desire
to protect this resource and use it wisely on a long-term basis—a con-
cept called land stewardship.
I would sincerely like to thank several of the federal government
agencies that study, manage, protect, and preserve the land each day—
in particular, the Bureau of Land Management (BLM), the U.S. Forest
Service (USFS), the National Park Service (NPS), the U.S. Department
of Agriculture (USDA), the Natural Resources Conservation Service
(NRCS), and the U.S. Fish and Wildlife Services (FWS) for providing
an abundance of learning resources on this important subject. I would
also like to acknowledge and thank the many universities across the
country (and their geography, ecology, and geology departments) as
well as the private organizations that diligently strive to protect our
precious land resources, not only at home but worldwide.
Acknowledgments
x
T
he lands of the Earth hold vast resources. From mountains to
deserts to forests to coastlines and grasslands, each environ-
ment—or ecosystem—offers a wide range of goods and services.
It is difficult to assign a total dollar value to the land’s resources. Some
values are quantifiable, such as the value of timber in forests, the graz-
ing potential in grasslands, or the food that is grown on farms. The
value of other resources is not as obvious, such as the aesthetic and
recreational values of hiking trails and campgrounds in mountains,
natural water filtration through aquifers, habitat for wildlife, carbon
storage, biodiversity, soil fertility, or the land’s role in the water cycle.
Some of these resources are renewable; others are not—but they are all
important to the environment.

Each component of an ecosystem plays a part in how the entire
ecosystem functions; and many components are interrelated. If one land
resource is mismanaged or depleted, it will often cause a ripple effect,
upsetting the balance in other areas and damaging the entire system.
Human impacts can have a tremendous influence on the land—both
directly and indirectly. Cutting down a forested area to build a housing
development and a road network is a direct effect. Polluting the atmo-
sphere with greenhouse gases, which can pollute the environment, upset
natural chemical balances such as the carbon cycle, and eventually lead
to climate change that then affects the landforms and resources in that
area, would be an indirect effect. When climate change causes drought,
it can destroy farmers’ ability to grow crops on the land.
The Earth’s landscapes can also tell a story. By understanding vari-
ous landforms, it is possible to study past climates and determine which
types of natural environments existed in the geologic past. Humans’
Introduction
xi
influence on the land tells its own story. For example, archaeologists use
these concepts to study past civilizations to determine not only what
their lifestyle was, but also what type of climate and vegetation existed at
the time. Studying the landscape can answer many historical questions
concerning the influence of both natural and human factors.
Lands: Taming the Wilds addresses the important resource issues
that we face today with the landscape, as well as future management
of the land in order to preserve and protect its resources and provide
responsible stewardship of the land for future generations to enjoy.
Chapter 1 presents the concepts of how the Earth’s landmasses have
changed over the geologic past, the effects of climate on the land, the
role of ecosystems, and the resulting distribution of resources.
Chapter 2 looks at the history of land use and its impact on civiliza-

tion and then examines more closely the evolution of land exploration
and use in the United States.
Chapter 3 addresses the renewable and nonrenewable resources
that are associated with rangeland, riparian corridors, wetlands, des-
erts, grasslands, wilderness areas, and parks and preserves. It also
addresses natural resource exploration and extraction.
Chapter 4 discusses the development of land resources and the role
of several natural systems, such as the rock cycle, the role of soil, the
water cycle, the nitrogen cycle, the carbon cycle, and the food chain.
It also looks at natural hazards and the consequences of development
within those areas.
Chapter 5 focuses on use of the land, such as rangeland and graz-
ing, agriculture and factory farming, the value of riparian areas, the
impacts of urbanization, the use of fragile desert resources, irrigation
and salinity, deforestation, pollution, and invasive species.
Chapter 6 illustrates the importance of land resources and the
goods and services that come from them, such as food, energy, carbon
storage, tourism, wildlife habitat, medicines, minerals, clean water, soil
stabilization, biodiversity, recreation, scenic beauty, and open space.
Chapter 7 looks at the management of natural resources and the
roles and responsibilities of the various government agencies through-
out the country, as well as the responsibilities of each individual. It
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xii
INTRoduCTIoN
examines resource decision-making issues and the technologies avail-
able today to enable scientists and managers to be efficient stewards
of the land. It examines emerging and cutting-edge management tech-
nologies involving geographic information systems (GIS), mathematical
modeling techniques, remote sensing technologies, and real-time moni-

toring tools.
Chapter 8 addresses the conservation of precious land resources.
It presents the concepts of land stewardship and sustainability and the
roles of designated wilderness, natural preserves and refuges, and
nat
ional parks throughout the country. It also takes conservation to a
personal level and illustrates how each individual can promote effec-
tive conservation.
Finally, Chapter 9 looks at future issues and sustainable resources.
I
t focuses on the importance of reducing, recycling, and reusing; con-
trolling land degradation; new technologies and developments; and our
responsibility to work with nature to create a productive and healthy
future.
xiii

CHAPTER
1
1
ConCepTs of
Land ResouRCes
I
n order to understand the land and the natural resources that land-
masses have to offer, it is necessary to have an understanding of how
they came to be. It is important to examine the types of natural
landscapes—or biomes—that exist, the basic processes of soil forma-
tion, and practical uses of the land.
Origin Of Landmasses
The continents on the Earth have not always been in the same geo-
graphical locations that they are in today. At one point in geologic

time, the world was made up of a single continent, called Pangaea. This
“super continent” eventually separated and drifted apart, forming the
seven different continents that exist today.
In 1912, Alfred Wegener, a German meteorologist, was the first
scientist to propose the theory of the drifting continents. He used
the theory of Pangaea’s existence along with climate-related field data
LANds
2
Plate tectonics has been at work since the Earth was formed. These reconstruc-
tions illustrate the movement of the continents from 620 million years ago to
the present.
CoNCEPTs oF LANd REsouRCEs
3
collected from rocks. He believed that the continents are made of
lighter rocks that rest on heavier crustal material—similar to an iceberg
floating on water. Wegener proposed that the positions of the conti-
nents are not rigidly fixed, but instead, move at a slow rate—roughly
one yard (one meter) per century.
It was not until the 1960s, that geologists gained the technology to
understand the processes at work that could move the Earth’s plates.
The concepts of seafloor spreading and plate tectonics emerged as
powerful new hypotheses to explain the features and movements of
the Earth’s surface. Scientists concluded that the Earth’s surface was not
composed of one large sheet, but was composed of more than 12 major
pieces of crust. These pieces of crust are called plates.
Each rigid plate, or slab, of lithosphere averages at least 50 miles
(80 kilometers) thick. These plates move relative to one another at
speeds of a few inches (centimeters) per year—at roughly the same
rate as a human fingernail grows. Although these velocities are slow by
human standards, they are extremely rapid by geologic ones. Plates can

move 30 miles (50 km) in one million years, and the plates have already
been in motion for 100 million years. Scientists recognize three com-
mon types of boundaries between the moving plates: (1) divergent, or
spreading; (2) convergent; and (3) transform, or sliding.
Divergent or Spreading Plates
Some adjacent plates are pulling apart, such as the Mid-Atlantic
Ridge, which separates the North and South American Plates from the
Eurasian and African Plates. This pulling apart causes a phenomena
called seafloor spreading as new material is added to the oceanic plates.
The best-known divergent boundary is the Mid-Atlantic Ridge. This
ridge is a submerged mountain range, which extends from the Arctic
Ocean to beyond the southern tip of Africa, but is just one segment of
the global mid-ocean ridge system that encircles the Earth. The rate of
spread along the Mid-Atlantic Ridge averages 1 inch (2.5 cm) per year,
or 16 miles (25 km) in a million years.
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4
Convergent Plates
Plates moving in opposite directions meet and collide with each other.
One of the plates is dragged down, or subducted, beneath the other. The
area where the plate sinks under the adjacent plate is called the subduc-
tion zone. Convergence can occur between oceanic-continental plates,
oceanic-oceanic plates, and continental-continental plates. An example
of a convergent plate is the Nazca Plate (oceanic), which subducts under
the South American Plate to create the majestic Andes Mountains in
South America. When plates push together, the Earth’s crust tends
to buckle and be pushed upward or sideways. This is also how the
Himalayan mountain range was formed. The Himalayas, towering as
high as 29,000 feet (8,854 m), form the highest continental mountains
in the world. Strong, destructive earthquakes and the rapid uplift of

mountain ranges are common. When an oceanic plate subducts under
another oceanic plate, a trench is formed. Trenches can be hundreds of
miles (km) long and 5 to 7 miles (8 to 10 km) deep, cutting into the
ocean floor.
Transform or Sliding Plates
The transform, or sliding, boundary is where one plate slides hori-
zontally past another. Most transform faults are found on the ocean
floor, offsetting some of the active spreading ridges and producing
zigzag plate margins. Shallow earthquakes are associated with them.
The best-known example of a sliding plate is the San Andreas Fault
Zone in California. The San Andreas, which is 800 miles (1,300 km)
long, slices through two-thirds of the length of California. Along it, the
Pacific Plate has been grinding horizontally past the North American
Plate for 10 million years, at an average rate of 2 inches (5 cm) per
year. Land on the west side of the fault zone (Pacific Plate) is moving
in a northwesterly direction relative to the land on the east side of the
fault zone (North American Plate). Because the plates are internally
rigid, they interact mostly at their edges. All plates move relative to
each other.
CoNCEPTs oF LANd REsouRCEs
5
The fOrCe ThaT drives TeCTOniC PLaTes
The tectonic plates do not randomly drift or wander about the Earth’s
surface; definite, yet unseen forces drive them. Scientists believe that
the relatively shallow forces driving lithospheric plates are also working
with forces that originate much deeper in the Earth.
From seismic and other geographical evidence and laboratory
experiments, scientists generally agree with Harry Hess’s theory that
the plate-driving force is the slow movement of hot, softened mantle
Although the Earth appears to be made up of solid rock, it is actually made

up of three distinct layers: the crust, mantle, and core. Each layer has its own
unique properties and chemical composition.
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6
that lies below the rigid plates. Scientists also accept that the circu-
lar motion of the mantle carries the continents along, much like a
conveyor belt.
Below the lithospheric plates, the mantle is partially molten and
can slowly flow in response to steady forces applied for long periods
of time. When solid rock in the Earth’s mantle is subjected to heat and
pressure in the Earth’s interior over millions of years, it can be softened
and molded into different shapes.
The movement within the mantle moves as a convection cell in a
circular motion, similar to heating a pot of thick liquid to boiling. The
heated liquid rises to the surface, spreads, and begins to cool; then it
sinks back to the bottom of the pot where it is reheated, rises again, and
repeats the process. Convection in the Earth is much slower than that
of boiling, thick liquid, however. In order for convection to occur, there
This illustration shows significant plate tectonic processes and landforms, such
as mid-oceanic ridges, hot spot volcanoes, subduction zones, mountain build-
ing, and volcano formation.
CoNCEPTs oF LANd REsouRCEs
7
must be a source of heat. Heat within the Earth comes from two main
sources: radioactive decay and residual heat.
Radioactive decay is a spontaneous process that involves the loss of
particles from the nucleus of an isotope (the parent) to form an isotope
of a new element (the daughter). Radioactive decay of naturally occur-
ring chemical elements (such as uranium, potassium, and thorium)
releases energy in the form of heat, which slowly migrates toward the

Earth’s surface. Residual heat is gravitational energy left over from the
formation of the Earth 4.6 billion years ago.
How and why the escape of interior heat becomes concentrated in cer-
tain regions to form convection cells is somewhat of a mystery. Scientists
do believe, however, that plate subduction plays a more important role
than seafloor spreading in shaping the Earth’s surface features and caus-
ing the plates to move. The gravity-controlled sinking of a cold, denser
oceanic slab into the subduction zone, dragging the rest of the plate along
with it, is considered to be the driving force of plate tectonics.
Scientists know that forces deep within the Earth’s interior drive
plate motion. However, because these powerful forces are buried so
deeply, no mechanism can be tested for directly and proved beyond a
doubt. The fact that the tectonic plates have moved in the past and are
still moving today is known, but the details of why and how they move
will continue to challenge scientists in the future.
Because the Earth’s plates have been in motion for millions of
years, there has been plate movement of hundreds of miles (hundreds
of km). For example, seafloor spreading over the past 100 to 200 mil-
lion years has caused the Atlantic Ocean to grow from a tiny inlet of
water between the continents of Europe, Africa, and the Americas into
the vast ocean that exists today.
The oceanic trenches are the deepest parts of the ocean floor.
One of the most famous trenches is the Mariana Trench, located in
the Pacific Ocean just east of the Mariana Islands near Japan, where
the faster-moving Pacific Plate converges against the slower-moving
Philippine Plate. The Challenger Deep, at the southern end of the
Mariana Trench, plunges deeper into the Earth’s interior—35,838 feet
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8
(10,923 m)—than Mount Everest, the world’s tallest mountain, rises

above ground. The Challenger Deep is the deepest known point in the
oceans, and is caused by the subducting ocean crust dragging the edge
of the continental crust down with it as it descends. It gets its name
from the British survey ship Challenger II, which initially located the
deep water off the Mariana Islands in 1951. Its exact depth was dis-
covered by the Japanese in 1984, from data obtained by an instrument
called a multi-beam echo sounder. The pressure is tremendous at this
depth—scientists believe it is 16,000 pounds per square inch.
Oceanic-oceanic plate convergence also results in the formation of
volcanoes. Over millions of years, the erupted lava builds up on the
ocean floor until the submerged volcano rises above sea level to become
The Earth is made up of a dozen or so major plates and several minor plates.
Tectonic plates are constantly on the move. The fastest plate races along at 6
inches (15 cm) per year while the slowest plates crawl at less than 1 inch (2.5
cm) per year. Most plates are part continental and part oceanic.
CoNCEPTs oF LANd REsouRCEs
9
an island volcano. Earthquakes are common along these areas, as well.
The most famous example of this is the Pacific Ring of Fire—a ring of
active volcanoes ringing the Pacific basin as a result of plate tectonics.
Not all plate boundaries are as simple as the three types of bound-
aries mentioned above, however. In some regions, the boundaries are
not well defined because the plate movement deformation occurring
there extends over a broad belt—called a plate boundary zone. These
areas typically have larger plates with several smaller fragments of
plates, called microplates, involved.
raTes Of mOTiOn
Scientists can determine the rates of plate movement over geologic
time by analyzing the ocean’s floor “magnetic striping.” Small grains
of magnetite, which are found within the volcanic basalt that makes

The Pacific Ring of Fire is a zone of frequent earthquakes and volcanic erup-
tions that encircles the basin of the Pacific Ocean. It is shaped like a horseshoe
and it is 24,856 miles (39,993 km) long. It is associated with a nearly con-
tinuous series of oceanic trenches, island arcs, and volcanic mountain ranges
and/or plate movements. It is sometimes called the circum-Pacific seismic belt.
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10
up the ocean floor, act like magnets. The grains of magnetite naturally
align themselves with the orientation of the Earth’s magnetic field.
When the magma solidifies, it effectively records the Earth’s magnetic
orientation (polarity) at the time it cools. Because the ocean plates are
moving away from the magma source (seafloor spreading), it creates
a “stripe” of basalt with the magnetite aligned to the current “north”
pole. Scientists know that the Earth’s polarity reverses in intervals over
time (the North becomes South and vice versa). When these polar-
ity reversals occur, the magnetic striping records the flip-flops in the
Earth’s magnetic field. In other words, a sequence of basalt may have its
grains oriented to the North followed by a sequence that has its grains
oriented to the South. Because scientists can calculate the approximate
duration of each reversal, they can calculate the average rate of plate
movement during a given time span.
Evidence of past rates of plate movement can also be obtained
from geologic mapping studies. If a rock formation of known age is
mapped on one side of a plate boundary and can be matched with the
same formation on the other side of the boundary, then measuring the
distance that the formation has been offset can give an estimate of the
average rate of plate motion.
The effeCTs Of CLimaTe On The Land
Climate is the characteristic condition of the atmosphere near the
Earth’s surface at a certain place on Earth. It is the long-term weather

of that area. This includes the region’s general pattern of weather
conditions, seasons, and even weather extremes such as hurricanes or
droughts. Two of the most important factors determining an area’s
climate are air temperature and precipitation.
The world’s different habitats—or biomes—are controlled by cli-
mate. The climate of a region will determine what vegetation will grow
there, what animals will inhabit the area, and what resources naturally
occur. The climate system is based on the location of hot and cold air
mass regions and the atmospheric circulation patterns created by the
trade winds and westerlies.