Transcript ppt

Interactions of
Organisms
Make two lists:
Living and Nonliving
What is Ecology?
• Study of interactions between
organisms and their environments
• Many factors affect the interactions of
organisms:
• Abiotic Factors (nonliving factors)—water,
temperature, light, nutrients
• Biotic Factors (living factors)—other
organisms living in the same environment
4 Levels of Ecological Study
Population
Community
• Group of individuals of
the same species
living in a particular
area
• All the organisms
living in a particular
area
Ecosystem
Biome
• A community along
with all abiotic
(nonliving) factors in a
particular area
• Major terrestrial area
and their ecosystem
Example of organization…
Population
Coyote Population
Community
All the organisms living in the desert
(coyotes, snakes, cacti, sage brush, hawks, etc)
Ecosystem
community + the abiotic factors (water, air, soil, etc)
Biome
The complete Desert Biome
Size of a Population
Size can be affected by:
1.
2.
3.
4.
Birth Rate (natality)
Death Rate (mortality)
Immigration: movement into an area
Emigration: movement out of an area
Stable Population…population with no
overall growth
• Births + Immigration = Deaths + Emigration
• Name two factors that can cause a
population to grow.
• What is the difference between
emigration and immigration?
• What term is used to represent all the
living organisms in an area?
• What is meant by abiotic factors?
Interactions Within a
Community
Competition
Predation
Symbiosis
Competition
• Competing for…
– Food, water, shelter, homes, space
• Interspecies Competition
– Competition BETWEEN different species
• Intraspecies Competition
– Competition WITHIN the same species
Predation:
Predator-Prey Interaction
What is it?
Interaction between
species when one
organism is the resource
(food) of the other
The size of the population of each is dependent
on the other
• Lots of prey….increase in predators
• Lots of predators…..decrease in prey
Symbiosis
Interaction of two organisms living together
Mutualism
Both Benefit
Commensalism
Parasitism
One benefits—One
unaffected
One benefits—One
harmed
1. Mutualism
• Both organisms benefit from the
interaction
• Examples:
– Flowering plants & Insects
– Nitrogen-fixing Bacteria & Legume plants
2. Commensalism
• An interaction when one benefits while the
other is neither harmed nor benefited
• Usually physical attachment of the
benefiting organism to the other (host)
Barnacles & Sea
Animals
• Protection
• Food Source
Tropical Fish & Sea
Anenomes
• Protection
• Not affected by the
stinging tentacles of
the sea anenome
3. Parasitism
• An interaction when one benefits while the
other is harmed
• Benefiting organism: parasite
• Harmed organism: host
• Examples:
– Lice
– Tapeworms