Chapter 3
Section 1:
The Changing Environment
Structure of an Ecosystem
In addition to abiotic factors, a(an)
ECOSYSTEM
includes
COMMUNITIES
Made up of
Different
POPULATIONS
Of organisms that are
Members of different
SPECIES
OBJECTIVE

Describe the ways in which
the layers of the biosphere
change over time.
Vocabulary
• Tectonic Plates
• Weathering
• Erosion
Introduction
• Earth is approximately 4.6 billion years
old
• Humans have existed for about 100,000
years
• Many rapid changes have taken place due
to results of human activity
Changes in the
Lithosphere
How are land
formations
created?
Movement of the
tectonic plates
Weathering
Erosion
Tectonic
Plates
Several large, movable
plates that make up the
lithosphere.
Tectonic Plates
Weathering
The breaking down of
rocks by weather
and water.
Weathering
Weathering
Weathering
Erosion
The wearing
away of land by
weather and
water; a natural
process where
soil is lost,
transported,
and reformed.
Erosion
Changes In The
Hydrosphere
ICE AGES
EL NIÑO
An Ice Age is a long period of
cooling during which huge ice
masses, called glaciers, grow
and extend from Earth’s
polar regions, covering much
of the planet’s surface.
Ice Ages
Ice Ages
• During the ice age, sea levels lower.
• As glaciers melt, sea levels rise.
• After an ice age, the glaciers melt and
shrink back toward the poles.
• Most recent ice age ended between
10,000 and 12,000 years ago.
Significant changes due to
glaciers
• Changes the shape of the land
• Scraping of ice across the land
• Displacement of rocks
• Large scale weathering and erosion
• Deposit of foreign minerals
EL NIÑO
EL NIÑO
• A current of warm, nutrient-poor water
that flows southward along the coast of
South America. Occurs every year near the
end of December
• Normally last for a couple weeks.
• When this current lasts for several months,
the condition is called El Niño.
EL NIÑO
• One of many recurring patterns of change in
the ocean.
• Change in water temperature and nutrient
content affects the survival of fish.
• Drop in fish means loss of income for the
fishing industry.
• Reduced supply of fish also means increased
costs for other industries that depend on
fish meal, such as poultry and egg farming.
• Climatic changes also damage crops.
CHANGES IN
THE
ATMOSPHERE
Background
Information
• Sunlight and Earth’s rotation drive many of the
daily and seasonal changes in the atmosphere.
• Before life on Earth, erupting volcanoes was the
source for Earth’s atmosphere.
• Organisms evolved and were able to combine
water, carbon dioxide, and energy from the sun
to produce food (Photosynthesis).
• This process released the first Oxygen (O2) into
the atmosphere.
Erupting Volcanoes
http://dsc.discovery.com/videos/volcanovideo/
Greenhouse Effect
• The trapping of radiated heat by gases in the
atmosphere.
• One way in which humans may be changing
Earth’s atmosphere.
• Loss of ozone (O3) from the stratosphere
and increased pollution in the troposphere
are other examples of atmospheric changes
caused by humans.
SECTION 3.1
REVIEW
Question #1:
Through what process does weather affect
the shape of land?
Answer:
Weather affects the shape of the land
through erosion.
Question #2:
In what ways does El Niño affect the
economy?
Answer:
By affecting climate and water quality,
farming and fishing industries are
affected.
Question #3:
Describe how ice ages are related to changes
in the lithosphere, hydrosphere, and
atmosphere.
Answer:
In age ices, the state of water changes in the
hydrosphere, air bubbles are trapped, and
land is eroded in the lithosphere.