Transcript Ecology of Organisms - Downey Unified School District

Ecology of Organisms
Biotic and Abiotic Factors
• The living components of the environment
are called biotic factors.
• The non-living components of an
environment are called abiotic factors.
The changing environment
• Abiotic factors are not constant
• Temperature varies
• The photoperiod varies with seasons
Response to a Changing Environment
• Organisms are able to survive within a
wide range of environmental conditions
• A graph of performance vs. values of
environmental variables is called a
Tolerance Curve
Acclimation
• Some organisms
can adjust their
tolerance to
abiotic factors
through a process
called acclimation.
Control of internal conditions
• Conformers are organisms that cannot
control their internal conditions. Ex
jellyfish, reptiles.
• Regulators control internal body
conditions and keep their bodies in the
optimal range over a wide variety of
environmental conditions.
Escape from Unsuitable Conditions
• Some species can escape from unsuitable
conditions temporarily, there are also
others who remain in a state of reduced
activity called dormancy
• Another way a species can cope with an
unsuitable environment is to leave or
migrate to more hospitable areas.
Resources
• Whether a species can survive in an area
depends on the suitability of environmental
conditions as well as availability of
resources.
The Niche (nich)
• The niche is a species way of life.
• A species’ fundamental niche is the
range of conditions that they could
potentially tolerate.
• A realized niche is the range of resources
that a species actually uses.
Niche Differences
• Generalists are species with broad niches.
– Opossum
– Raccoon
• Specialists are species with narrow niches.
– Koala
p. 372
1. List three abiotic factors that can affect an
organism
2. What does a tolerance curve indicate curve
indicate about an organism
3. What is migration? Give an example of
migration.
4. How is an organism’s niche different from it’s
habitat.
5. List two factors that might cause an organism
to restrict its use of a resource.
6. Explain why two different species do not
occupy exactly the same niche.