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Ecology
Ecology
• Ecology – is the
scientific study of the
interactions among
organisms and between
organisms and their
environments.
Habitats
• The place where an organism lives and that provides
the things the organism needs is called its habitat!
– Food, water, and shelter.
• Biotic Factors – The living parts of an ecosystem.
– Animals, plants, fungi, bacteria.
• Abiotic Factors – The nonliving parts of an
ecosystem.
– Water, Sunlight, Oxygen, Temperature, and soil.
Organism
• The smallest unit of
ecological study.
– Wildebeest
Populations
• A population is a group
of individual organisms
of the same species
living in a particular
area.
– Herd of Wildebeest
Exponential Growth
• Occurs when the
population multiplies by
a constant factor at
constant time intervals.
Limiting Factors
• A factor that restricts
the growth of a
population.
– Space
– Food availability
– Disease
Community
• All of the organisms
inhabiting a particular
area make up a
community.
Ecosystem and Biosphere
• An ecosystem includes
the abiotic and biotic
factors in an area.
• The biosphere is the
sum of all Earth’s
ecosystems.
How do organisms get energy?
• Every organism requires energy to carry out
life processes such as growing, moving, and
reproducing.
– Producers (autotroph) – synthesize their own food
through the process of photosynthesis.
– Consumers (heterotrophs) – obtain their energy
by eating other organisms.
– Decomposers -
Types of Consumers
• Herbivore – eats plants.
• Omnivore – eats plants
and animals.
• Carnivore – eats
animals.
Food Chains
• The pathway of energy
transfer form one
organism to another is
called a food chain.
• What would happen if
one organism is
overhunted and
removed from the food
chain?
• What is the source of
all energy?
Food Web
• A pattern of feeding represented by
interconnected and branching food
chains is called a food web.
Energy Pyramid
• Emphasizes the energy loss from one
organism to the next in a food chain. Only 10
% is passed on to the next level, the rest is lost
to the ecosystem in the form of heat.
Types of Relationships among species!
• Predation – an
interaction in which one
organism eats another.
There are two
individuals that
participate.
• Predator and Prey
• Fox is a predator and
the rabbit is the prey.
Symbiotic Relationships
• A symbiotic relationship is a close interaction
between species in which one of the species
lives in or on the other.
– Parasitism – one benefits and the other is harmed.
– Mutualism – both species benefit
– Commensalism – one benefits and the other is
neither helped or harmed
Ecological Succession
• The process of community change is called
ecological succession.
• What would happen if you left the field
behind Heritage uncut for a couple of years?
Primary Succession
• When a community
arises in a lifeless area
that has no soil.
• Pioneer species are the
first to colonize barren
rock.
• Climax community takes
hold several hundred or
thousand years later.
The forest has grown to
its full capacity.
Secondary Succession
• When a disturbance
damages an existing
community but leaves
the soil intact, the
change that follows is
called secondary
succession.
– Fires
– Land cleared for farming,
then abandoned.
The Carbon and Oxygen Cycle
• Carbon starts its cycle in the
atmosphere as Carbon
Dioxide.
• Plants take in the carbon
dioxide and make organic
compounds known as glucose.
• That glucose gets passed on to
consumers through the food
chain.
• They then release carbon
dioxide back into the
atmosphere through the
process of cellular respiration.
Human Activities can alter
ecosystems!
Population Growth
• As the human population continues to grow,
the environment will be negatively impacted
by the following.
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Habitat destruction
Deforestation
Air Pollution
Acid Rain
Water pollution
Global Warming
Introduced Species
Reduced Biodiversity
Overexploitation
Deforestation
• The clearing of forest
for agriculture, lumber,
and other uses also
affects the carbon cycle
by eliminating plants
that absorb CO2 for
photosynthesis.
Alternatives to Clear cutting
• Don’t cut down every
single tree!!!!!!
• Selective Cutting
Greenhouse Effect
• They process by which
atmospheric gases trap
heat.
• Greenhouses trap heat.
Global Warming
• The overall rise in Earth’s
average temperature.
– Caused by increasing
carbon levels in the
atmosphere.
• What causes increased
carbon levels in the
atmosphere?
– Deforestation
– Burning of Fossil Fuels
• Effects of Global
warming
– Rising sea levels
– Large effects on weather
– Loss of Species
Acid Rain
• Precipitation that carries
acid to the Earth’s surface.
– Smokestacks and automobile
exhaust pipes release
nitrogen and sulfur
compounds into the
atmosphere. They then
combine with water and form
acid rain.
– Can lower pH of soil and
aquatic ecosystems causing
species to become extinct.
• Acid Rain
Water and Air Pollution
• Burning Fossil Fuels –
Releases chemicals into
the atmosphere.
• Fertilizers – end up in
water supplies.
Introduced Species
• Starlings and house sparrows are introduced
species from Europe. They competed with the
bluebird population drastically reducing its
population.
Snakeheads
• Snakeheads are very aggressive and are
outcompeting all native fish populations.
Examples include Bass, Pickerel,
Overexploitation
• The practice of overhunting.
– Elephants were hunted for their tusks
What can Humans do to reduce
our negative impact on the
environment?
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Selective cutting
Make our homes more energy efficient
Use cars get higher gas mileage
Tougher regulations