Download Chapter 3 Changes in the Biosphere

Chapter 3
Changes in the Biosphere
3.1 The Changing Environment
3.2 Needs of Organisms
3.3 The Ecosystem
3.1 The Changing
Environment
Objectives:
•Describe ways in which the three
layers of the biosphere change over
time.
Changes in the Lithosphere
• What is the lithosphere?
• How does the lithosphere change?
– One way is through tectonic plates.
• Tectonic plates- one of several large,
movable plates that make up the
lithosphere.
• Figure 3.1 page 35 – tectonic plates
Tectonic Plates
• Liquid rock rises through cracks between the
plates.
• Deep in the ocean when this liquid rock meets
the cool ocean water it hardens and forms new
rock.
• The new rock pushes the tectonic plates apart,
causing them to shift their position.
• When tectonic plates shift positions,
earthquakes occur.
• Mountains rise when this movement of the
plates causes the earth to buckle
Weathering and Erosion
• Besides tectonic plates; weathering and
erosion is another way the lithosphere is
changed.
• Weathering- the breaking down of rocks
by weather and water.
• Erosion- the wearing away of land by
weather and water; a natural process
where soil is lost, transported, and
reformed.
Weathering and Erosion
• What is the difference?
• Weathering and erosion shape mountain
ranges and help to form streams
• Together with tectonic plates weathering
and erosion have produced the land
formations we see today.
Changes in the Hydrosphere
• What is the hydrosphere?
• Changes to the hydrosphere in some
areas have progressed slowly and
steadily.
• Other changes occur in cycles
– Ice Ages
– El Niño
Ice Ages
• Ice age- long period of cooling during
which huge ice masses, called glaciers,
grow and extend from Earth’s polar
regions.
• During ice ages the sea levels lower.
– Why?
• Scientist have found evidence for a least five major ice
ages
– The most recent being 10,000 – 12, 000 years
• Not only do ice ages effect the hydrosphere, but the
glaciers cause significant changes to the lithosphere.
– As the glaciers move across the land the pick up
rocks. These rocks then move across the land
scraping the surface.
– When the glaciers retreat the rocks and other
materials are now deposited in another area.
• Bolder Field and Blue Mountain
El Niño
• El Niño – a disturbance of ocean winds and
currents when a warm-water current lasts for
several months along the western coast of South
America
• This current usually only lasts of few weeks, but
when it last longer it become the condition El
Niño
• It is a recurring pattern with far reaching effects
on climate and the economy
The Effect of El Niño
• The change in water temperature and the
nutrients affects the survival of fish
• When the fish begin to die then the fishing
industry suffers.
• This also effect the poultry industry which
depends on fish meal
• The climate change also damages crops
• No body knows the exact cause of El Niño
Changes in the Atmosphere
• What is the atmosphere?
• Sunlight and Earth’s rotation drive many of
the changes in the atmosphere
• Organisms have a huge effect on the
atmosphere
Early Atmosphere
• Before there was life the atmosphere was made
up of many gases:
– Water vapor
– Carbon dioxide
– Sulfur gases
• These gases are released by volcanoes, which
was the source of Earth’s early atmosphere
• As organism evolved that could combine water
vapor and carbon dioxide and release oxygen
the atmosphere changed
Atmosphere
• For about 3.5 billion years, oxygen, carbon
dioxide, water vapor, and nitrogen have
been cycling from the atmosphere to
organisms and back again.
– Much of the carbon on earth is stored in the
bodies of organisms, both alive and dead
– Coal and other fossil fuels is an example of
how carbon is stored
– When fossil fuels are burned they release this
carbon back into the atmosphere
Greenhouse Effect
• Burning of fossil fuels release carbon back
into the atmosphere causing and increase
in atmosphere temperature.
• Greenhouse effect- the trapping of
radiated heat by gases in the atmosphere.
Causes of Change to the
Atmosphere
• Human:
– Greenhouse effect
– Pollution resulting in the depletion of the
ozone layer
• Natural:
– Volcanic eruption
Review
• How does change occur in the
lithosphere?
• How does change occur in the
hydrosphere?
• How does change occur in the
atmosphere?
3.2 Needs of Organisms
Objectives
•List factors that affect an area’s ability to
support life.
•Predict how changes in the environment
might affect organisms.
What does my fish need?
• Alone or in a group of two; determine what
my fish needs to survive.
• Include everything I need to maintain a
happy, healthy fish.
• Let’s see what group will have the
happiest fish?
What do organisms need to
survive?
• For this chapter we will look at four things
that are necessary for an organisms to
survive:
– Water
– Food and Energy
– Living Space
– Climate
Water
• Fresh water is one of the most important
things organisms need to survive.
– Water is needed for plants to grow and
animals need both water and plants to
survive.
• The amount of rainfall an area receives
directly effect the number and kind of life
that exists there.
Water and Aquatic Organisms
• Aquatic organisms are as affected by the
amount of rainfall, but by the quality of the
water.
– Pollutants and amount of dissolved oxygen
have a huge effect on aquatic organism.
Food and Energy
• Almost all of the energy used by living
things originates from the sun.
• Plants capture energy from the sun during
photosynthesis.
• Animal get their energy by eating plants
and/or other animals
Food
• Contains energy, minerals, vitamins and other
chemicals.
• These material are used for building tissues and
carrying out biochemical reactions.
• Nutrients – a substance needed by the body for
energy, growth, repair or maintenance.
– Animals obtain their nutrients from the things they eat.
– Fungi, protists, plants and some animals (worms)
absorb nutrients directly into their cells
Poisons
• Some of the substance stored by
organisms are harmful, making tissues
poisonous if eaten by other organisms.
• This buildup allows poisonous to move
from one organism to another in the
environment
Living Space
• All organisms need enough space to live.
• It is from your living space that you obtain
the things you need to survive
– Plants need enough space to obtain sunlight
and enough space for their roots to spread
out to absorb water and minerals.
– If plants are too close together they may die.
Living Space
• Animals need enough living space to seek
food, water, shelter and mates.
• Some animals will claim a space as their
own.
• Territory – a living space claimed by an
individual or group of animals as their own.
These animals are referred to as territorial
animals
Territorial Animals
• Many territorial animals will mark their territory with their
scent.
– Urinating
– Defecating
– Scent glands
• Another way is through sounds or gestures.
• The size of an animals territory is determined by his
needs.
• Animals may compete with one another for territory.
Sometimes even to the death.
• The competition for space and resources is an important
factor in evolution.
Climate
• The body temperature of many organisms is
determined by the temperature of the
environment.
– When it becomes colder out – their body temperature
drops.
• Most organisms have a small temperature range
at which they can survive.
• It is this temperature range that determines
where on the globe you will find certain
organisms.
– You would not find a snake in the tundra.
Climate
• One of the adaptation the animals have to
survive in colder temperature is becoming
dormant.
• Dormant- the life processes within the
body slow down
– Plants lose their leaves and stop growing
– Bacterial growth is reduced at colder temps.
Warm-blooded organisms
• Birds and mammals maintain high body
temperatures regardless of the
environmental temperature.
• Warm-blooded animals have a wider
range of temperature tolerance and live in
more diverse climate.
Adaptation
• Maintain this higher temperature requires a lot of
energy
• Warm-blooded animals need about ten times
more food than other animals the same size
• One adaptation animals have to help them is
hibernation.
• Hibernation – dormancy in some animals when
the heart rate and breathing slow down, the
body temperature drops and the animal enters a
sleeplike state.
Hibernation
• Energy requirements are lowered during
this time.
• This enables animals to survive long, cold
periods with little food.
• Example:
– Groundhogs
– Snakes
Review
• What does an organisms need to survive?
• How might a change in a organism’s
environment effect its chance of surviving?
3.3 The Ecosystem
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Objectives:
Describe the structure of an ecosystem.
Relate the concept of habitat destruction to the
loss of biodiversity.
Species
• Species - a group of organism so similar to one
another that they can breed and produce fertile
offspring.
• All members of a species have similar need:
– Range of climate tolerance
– Size of territory
– Types of food
• Because species have the same needs they
often compete with one another.
Habitat
• Habitat – the specific environment in which a
particular species lives
• Examples:
– The top of trees in the rainforest
– Stream-shallow, slow-moving and cold
• It is within habitats the organisms find food,
shelter, temperature and all other factors
needed to survive.
• The destruction of habitats is one of the most
serious threats to species today.
Geographical Range
• Geographical Range - the total area in
which a species can live.
• Mountain lions require a habitat with
diverse plant life and a large hunting
territory with a variety of prey.
• This type of habitat use to exist all over the
US, so their geographical range was the
US.
• That is not true today; their range is much
smaller.
Populations and Communities
• Populations- all the members of a species
that live in the same geographical area
• Example:
– All the dandelions in a field are a population.
– The ants in an anthill
• Populations do not live alone in their
environment; many other populations of
organisms are also present.
Communities
• Community - all the different populations
that live and interact in the same area.
• Communities refer to the vegetation along
with the animals that live there.
• Examples:
– Grassland communities
– Desert communities
Ecosystem
• Ecosystem - includes all the communities in an
area, as well as the abiotic factors in the
environment.
• Includes: Water, soil, atmosphere and energy cycles.
• A healthy ecosystem has a wide variety of
organisms.
• Biodiversity - the variety of species in an ecosystem.
– When a habitat is destroyed everything living in it
can become extinct. When species become
extinct, biodiversity and stability are reduced
Review
• What is included in an ecosystem?
• How is habitat destruction and the loss of
biodiversity related.