Transcript Ecology Lecture I

Ecology Lecture I
The study of complex interactions among
organisms and the world
Ecology Standards:
6a ~ Students know biodiversity is the sum total of different
kinds of organisms and is affected by alterations of habitats
6b ~ Students know how to analyze changes in an
ecosystem resulting from changes in climate, human
activity, nonnative species introduction, or changes in
population size
Human Impact
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In the late 1700’s an economist by
the name of Thomas Malthus stated
• “the human population is growing faster
than the Earth’s resources can support”
• Naturally, the rest of the world didn’t
believe these claims
• The world’s population was around 1
billion people worldwide at this time
Human Impact
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Scientists tried to predict human
population growth and vastly
underestimated it!
Today we have gone past the
predicted carrying capacity with a
world population of over 6 billion!
• Carrying capacity – the maximum number
of individuals that the environment can
normally and consistently support
Human Impact

Several human “advancements”
have made it possible for the human
population growth explosion!
• Technology
• Agriculture
• Transportation
• Medical advancements
• Sanitation
Human Impact

Oil and Coal
• These natural resources are
what humans have relied
upon for power for the last
258 years
• Oil and coal are considered
nonrenewable resources
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Nonrenewable resources –
resources that are used faster
than they are replenished
Human Impact
• If humans continue at the rate of 77
million barrels of oil per day (and
growing) we will quickly approach or
exceed our carrying capacity!

We must make a choice to invest in
renewable energy technology if we
wish to survive and preserve a
planet capable of supporting life
• Renewable energy – resources that
cannot be used up or replenish
themselves regularly
Human Impact
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Water is considered a renewable
resource because of annual rains
and snow ‘returning’ water back to
the earth
Humans are finding ways to make
water a nonrenewable resource by
polluting water sources and
overuse!
Human Impact
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Humans need resources in order
to survive
There is a problem when people
need too much!
An ecological footprint is the
amount of land and resources
necessary to maintain an
individual
• Maintenance includes: food, water,
shelter, health, energy, and waste
Human Impact

What is Global Warming?
• The trend of an increasing global
temperature

What contributes to Global Warming?
• Our earth is protected by a thin layer of
atmosphere from outer space
• Greenhouse gases are certain gases that
become “trapped” by the ozone around our
planet

Gases like CO2, Methane CH4, and water vapor
Global Warming
Levels of Organization
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An ecologist is a scientist that studies the interactions
of living things with other living things and their
surroundings
When ecologists study organisms in their
environment they look at the levels of
organization
When studying nature, scientists
recognize 5 levels of organization
Levels of Organization
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Levels of Organization:
• Organism – any individual living thing
(example: a single alligator)
• Population – a group of the same species
that live in the same area
• Community – groups of different living
species that live together in the same area
• Ecosystem – the community and all of the
non-living components such as water, soil,
mountains, etc.
• Biome – a major region of the planet that
has a defined climate (ex: deserts)
Levels of Organization
Factors in an Ecosystem
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All ecosystems are made
up of living and nonliving
components
Biotic factors – are all of
the living parts of an
ecosystem such as
plants, animals, fungi,
and bacteria
Abiotic factors – are the
nonliving components
such as temperature,
water, wind, sunlight, and
Earth’s landmasses
Factors in an Ecosystem
ECOSYSTEM
Abiotic Factors
Biotic Factors
Factors in an Ecosystem
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An ecosystem is a
complex web of
biotic and abiotic
factors
• Some ecosystems
have more diversity
than others
• Biodiversity – is the
assortment or
variety of living
things in an
ecosystem
Biodiversity
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Biodiversity is the sum total of
different kinds of organisms and it is
affected by changes in the habitat
Factors in an Ecosystem
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Certain ecosystems are
held together because of
the actions of one biotic
factor
A keystone species is a
biotic organism that has
an unusually large effect
on its ecosystem
• For example: the beaver
creating a dam and a
large body of water