Ecology
Ch2 Sec 3
Page 39-42
Ecology links
Life Science &
Earth Science

Ecology is the study of the complex
relationships between living things and
their nonliving, or abiotic, environment
Ecosystems

A community of organisms and the
environment that the organisms inhabit
is an ecosystem

From the Greek oikos—eco
– Means house
Distribution of
Ecoystems
Ecosystems have
ABIOTIC COMPONENTS
BIOTIC COMPONENTS
Sunlight
Primary producers
Temperature
Herbivores
Precipitation
Carnivores
Water or moisture
Omnivores
Soil or water chemistry (e.g., P, NH4+)
Detritivores
etc.
etc.
Elements

Producers—produce their own
food
– Plants



Consumers—get their energy
from eating other organisms
Some consumers get their
energy breaking down dead
organisms—decomposers
Healthy systems have a balance
of producers, consumers, and
decomposers
Balancing Forces in
Ecosystems
Organisms use matter and energy
 Because those amounts are limited so
is the number of organisms


The largest population that an
environment can support at any given
time is called the carrying capacity
Ecological Responses
to Change
Events such as forest fires can disrupt
ecosystems
 Often organisms move elsewhere if
other land is available and return when
the area has recovered

Succession
Primary—entrance of life to a formerly
lifeless area—after a lava flow, after a
glacier
 Secondary—reentry of life after a
disaster
 Climax community—when the
ecosystem reaches a point of
equilibrium

Primary Succession
Secondary Succession
Climax Community

Occurs after many years when the
ecosystem reaches maturity and
populations remain relatively constant.
Energy transfer
The ultimate source of energy is the
sun
 Plants capture energy by a chemical
process known as photosynthesis
 This energy then flows through the
ecosystem through the plants

Energy pyramid
Energy is changed in
a series of chemical
reactions
The amount of energy
decreases in each
transfer as some is
lost
Food web

A diagram that
shows the feeding
relationship among
organisms in an
environment
Human Stewardship


Changes in
ecosystems can
affect the ability of
an area to sustain a
human population
Ecological balances
can be affected by
human activity
Check out these sites
 Food
web info
http://www.vtaide.com/png/foodchains.
htm
Extension
Extensions are information as to where
to find extra material about an
interesting subject.
 If you find a topic you are very
interested in, consider doing extra
credit research over the topic.
