Download Ecology is the study of relationships between living things and

2/6/2013
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February 6, 2013
Ecology
Study Island lesson: 3e and 3f
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Please close all other apps & web pages. No Facebook,
games, music, etc.
No off-topic chat
Be respectful of each other
Don’t share personal information
I can see all chat … even “private chat”
OH Grade 6-8, Science Standard
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Ground rules
Standard
I can statements
Ecology
Exit statement
File transfer
Questions
Life Sciences D
Explain how extinction of a species occurs when the
environment changes and its adaptive characteristics are
insufficient to allow survival (as seen in evidence of the fossil
record).
Covered by topics:
Adaptation & Natural Selection
Ecosystems: Energy Transfer & Population Dynamics
Environmental Changes & Extinction
I can…
• Explain how organisms interact with
each other and what happens as a
result of abiotic and biotic factors
• Describe how population dynamics
works and be able to describe
examples
 Ecology
is the study of
relationships between living
things and between living
things and their environment.
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Ecosystem is a system of living
things that interact with each
other and with the physical
world.
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Rabbits were introduced to Australia in 1859.
With only 24 rabbits, the population exploded to
cover the whole continent in 40 years.
Problems:
Destruction of vegetation and extinction of some
plant species
 Soil erosion
 Extinction of native animals like the bilby
and the bandicoot
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A Biome is a collection of related
ecosystems.
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Solutions:
Build a fence so they stay in one area
Introduce a disease to kill off the over-abundance.
 In 1950, the myxomatosis virus initially wiped out
between 95 and 100% of rabbits in some areas.
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 Problem: rabbits became immune to the disease
 Killed off too many, leaving some predators starving
http://www.animalcontrol.com.au/rabbit.htm
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Desert
Rainforest
Ocean
Taiga
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Tundra
Chaparral
Grassland
Temperate
Forest
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 Are
nonliving physical
factors of an environment.
An ecosystem can be as large as the
Sahara Desert, or as small as a
puddle!!!
Ecosystems are more than just the
organisms they contain. Geography,
weather, climate and geologic
factors also influence the
interactions within an ecosystem.
List
three more
examples of Abiotic
Factors:
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Abiotoic Factors include amount of water and
oxygen, temperature, amount of sunlight and
water pressure.
The abiotic factors of an ecosystem often
determine what living things can live there. For
example, animals that can survive in the Arctic
are adapted to cold climates, while animals that
can survive in deserts are adapted to dry
climates. The abiotic factors of an ecosystem
also provide most of the basic needs of plants
and animals.
So what lives here??
This place was
a bit
too…………………….
Hot, Dry but
at least you
don’t get
bothered by
people
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I do
It’s the right
temperature
and no-one but
no-one messes
with me
 Are
the living, physical
factors of an environment.
 The
place in which an
organism lives
 provides
Plants and fungi are both
biotic components of this
ecosystem.
the kinds of food and
shelter, the temperature, and the
amount of moisture the organism
needs to survive
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Ecosystems will fail if they do not
remain in balance.
No community can carry more
organisms than its food, water and
shelter can accommodate.
A food chain
is a simple
model of the
feeding
relationship
in an
ecosystem.
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To succeed in an ecosystem, plants
and animals have special structures
and behaviors called adaptations.
Ex) Chameleon
Polar Bear
Can you think of more examples of adaptation?
For example, shrubs are food for deer, and
deer are food for mountain lions. The mountain lion is
Shrubs are the
beginning of the
food chain. They
receive their
energy from
sunlight. Producer
The deer is the
first organism
of the food
chain to eat
the shrub. It
is the primary
consumer.
the second organism
of the food chain. It
eats the deer. It is the
secondary consumer.
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The first organism in
a food chain is
always a producer.
They make their own
food.
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A food web is a group of interconnected food
chains. Organisms within a food web can
belong to more than one trophic level, or
feeding level.
All the organisms in an
ecosystem that belong to the
same species
All the populations in an
ecosystem
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Populations of organisms do not grow linearly.
That is, graphs of their populations do not form
a straight line. Instead, populations grow
exponentially because the more organisms there
are, the faster the population grows.
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The presence of predators usually increases
the number of different species that can
live in an ecosystem. Predators limit the
size of prey populations. As a result, food
and other resources are less likely to
become scarce, and competition between
species is reduced.
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Needed resources that are present in limited
quantities
Can be abiotic or biotic
Reproduction rates or the presence of disease
 Availability of good soil or lack of direct sun
 Competition for food
 Over-hunting or chemical spills
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Different ecosystems can have different
limiting factors
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The maximum number of individuals of a
population that a particular environment can
support for a long time.
As a growing population reaches the limits of
the available resources in an environment, its
size levels off to "match" the amount of
resources available.
When this happens, the population has reached
its carrying capacity.
For example, if the major food source of a
population dies out, the carrying capacity for
that population will drop. Conversely, an
increase in available food can cause the
carrying capacity for an organism to increase.
The pattern of population growth will vary as
environmental conditions change. These changes
could include:
a change in the food supply
a change in the water supply
a disease epidemic
the creation of new vaccines
a change in temperature
storms, earthquakes, and other natural disasters
crowding and competition
predator-prey relationships
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Populations in an ecosystem affect one another.
A change in the number of one type of
organism will cause a change in the number of
other types of organisms. These changes can be
studied by looking at the population dynamics
of an ecosystem.
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Example of a food web:
Antelopes depend on the
leaves from the tree as their
food source. The wild dog and
the lion compete with each
other for the antelope.
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Another example would be if humans hunted
and killed many of the African wild dogs and
lions. This would cause an increase in the
antelope population because they would not
have as many predators. More antelope means
they would eat more leaves from trees. This
would decrease the amount of leaves, which is
a resource.
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If a drought in the ecosystem caused many of
the trees to die, there would not be enough
food for all of the antelope to survive. The
antelope population would decrease. If the
antelope population decreased, the number of
African wild dogs and lions would also likely
decrease because they would be losing a major
food source.
All populations within an ecosystem are
related in some way. This means that a change
in even one population in an ecosystem can
have drastic effects on the ecosystem as a
whole.
Section Summary
• A food chain models
the feeding
relationships
between species.
http://www.learner.org/courses/envsci/interactives/ecology/food_web.php
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Section Summary
Section Summary
• Consumers cannot
make food. They
obtain energy by
eating producers and
other consumers.
• Ecosystems are
maintained by the
population growth
staying at a steady
balance.
Section Summary
Links
• When the carrying
capacity of an
Ecosystem is reached,
something has to
change; birth rate,
death rate
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http://www.teachersdomain.org/resource/lsps07.sci.life.eco.oceanfoodweb/
http://www.learner.org/courses/envsci/interactives/ecology/producers_1.php
http://www.harcourtschool.com/activity/food/food_menu.html
Be sure to do a Pathway a Day.
Don’t forget Math Pathways!
Science SI: 3e and 3f this week.
I think I am an expert
I think I have a good idea
?
I think I have got some of it
Help – can you go through it
again
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3.
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