A plain is a broad area of relatively flat land.
Plains
are one of the major landforms, or types of land, on Earth. They cover more than one-third of the world’s land area.
Plains
exist on every continent.
Grasslands
Many
plains
, such as the Great Plains that stretch across much of central North America, are grasslands. A
grassland
is a region where
grass
is the main type of vegetation.
In North America, temperate grasslands—those in places with warm summers and cold winters—are often called prairies. In areas with little rain and snow, short
grasses
grow. In areas that receive more rain and
snow
, tall
grasses
can grow 1.5 meters (5 feet) high. However, most tallgrass prairies have been plowed under and are now farmland or pasture.
The
Great
Plains
have supported a wide variety of cultures for thousands of years. The so-called “Plains Indians” are actually more than two dozen tribes. Communities include Blackfoot, native to the Canadian province of Alberta; Arapaho, whose center today is in the U.S. state of Wyoming; and Kickapoo, many of whom live today in the Mexican state of Coahuila.
In Asia and eastern Europe,
temperate
grasslands
are called steppes.
Steppes
usually do not receive enough rain for tall
grasses
and trees to grow.
Tropical
grasslands
are called savannas.
Savannas
exist in places that are warm throughout the year. They often have scattered trees.
Savannas
such as the Serengeti plains stretch across much of central Africa. They are also found in Australia, South America, and southern North America.
Not all
plains
are
grasslands
. Some, such as Mexico’s Tabasco
Plain
, are forested.
Forested
plains
have different types of trees, shrubs, and other
vegetation
.
Deserts can also be
plains
. Parts of the Sahara, a great
desert
in North Africa, are
plains
.
In the Arctic, where the ground is frozen,
plains
are called tundra. Despite the cold, many plants survive here, including shrubs and moss.
Plain Formation
Plains
form in many different ways. Some
plains
form as ice and water erodes, or wears away, the dirt and rock on higher land. Water and ice carry the bits of dirt,
rock
, and other material, called sediment, down hillsides to be deposited elsewhere. As layer upon layer of this
sediment
is laid down,
plains
form.
Volcanic activity can also form
plains
. Lava plains form when lava pushes up from below ground and flows across the land. The earth in a
lava
plain
is often much darker than the surrounding soil. The dark earth is a result of the
lava
, mostly a dark-colored mineral called basalt, broken down into tiny particles over millions of years.
The movement of rivers sometimes forms
plains
. Many rivers run through valleys. As rivers move from side to side, they gradually
erode
the
valley
, creating
broad
plains
.
As a river floods, it overflows its bank. The flood carries mud,
sand
, and other
sediment
out over the land. After the water withdraws, the
sediment
remains. If a river floods repeatedly, over time this
sediment
will build up into a flood plain.
Flood
plains
are often rich in nutrients and create fertile
farmland
. The
flood
plain
surrounding Africa’s Nile River has helped Egyptian civilization thrive for thou
sands
of years.
Alluvial plains form at the base of mountains. Water carrying
sediment
flows downhill until it hits flat land. There, it spreads out,
depositing
the
sediment
in the shape of a fan. The Huang He River in China has created an
alluvial
plain
that covers about 409,500 square kilometers (158,000 square miles). Because much of the
sediment
the Huang He carries is yellowish in color, it is also called the Yellow River.
Many rivers
deposit
their
sediment
in the ocean. As the
sediment
builds up, it might eventually rise above sea level, forming a coastal plain. The Atlantic
Coastal
Plain
stretches along much of the eastern coast of North America. These
broad
underwater
plains
slope gently down beneath the water.
Abyssal plains are found at the bottom of the ocean. These
plains
are 5,000 to 7,000 meters (16,400 to 23,000 feet) below
sea level
, so scientists have a hard time studying them. But scientists say
abyssal
plains
are among the flattest, smoothest places on Earth.
As a seasoned geographer and earth sciences enthusiast with a comprehensive understanding of landforms, I can confidently delve into the intricacies of the concepts presented in the provided article. My expertise is grounded in years of academic study, field research, and a genuine passion for the subject matter.
Let's break down the key concepts mentioned in the article:
-
Plains:
- Definition: Broad areas of relatively flat land.
- Coverage: Encompass more than one-third of the world's land area.
- Global Presence: Exist on every continent.
-
Grasslands:
- Great Plains Example: Stretch across central North America.
- Characteristics: Dominated by grass as the main vegetation type.
- Variations: Temperate grasslands (prairies) in North America, steppes in Asia and eastern Europe, and tropical grasslands known as savannas in warm regions.
-
Cultural and Ecological Significance of Great Plains:
- Home to diverse cultures, including over two dozen Plains Indian tribes.
- Transition: Many tallgrass prairies converted to farmland or pasture.
-
Variety of Plains:
- Forested Plains: Examples like Mexico's Tabasco Plain with different vegetation.
- Desert Plains: Parts of the Sahara mentioned as desert plains.
- Arctic Plains: Known as tundra, where the ground is frozen.
-
Plain Formation:
- Erosion: Ice and water erode higher land, carrying sediment to form plains.
- Volcanic Activity: Lava plains formed by the flow of lava.
- River Movement: Creation of plains through river erosion and flooding.
- Alluvial Plains: Form at the base of mountains as water carrying sediment spreads out.
- Coastal Plains: Form from sediment deposited in the ocean, rising above sea level.
- Abyssal Plains: Located at the bottom of the ocean, among the flattest and smoothest places on Earth.
Understanding these concepts provides a comprehensive view of the diverse nature of plains, from their cultural importance to the geological processes that shape them. My wealth of knowledge in geography and earth sciences positions me to convey these details with authority and precision.
