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Interactions in Ecosystems
Birth of an Ecosystem
Surtsey Island, Iceland
http://www.youtube.com/watch?v=4MmX_i7S9u4
Ecosystem Interactions
Competition:
Is the interaction between two or more organisms competing for the
same resource in a habitat.
Competition can happen between the same species. Example:
Male mountain goat competing for the right to mate.
Competition can happen between different species. Example:
Raccoons and ravens can both feed on eggs from the same bird’s nest.
Ecosystem Interactions
Predation
Occurs when one organism eats another organism to
obtain food.
What are some examples of the methods animals use to avoid
predation?
Chameleon – colour change to blend with surroundings
Porcupine – throws needles
Deer – can usually outrun a bear
Types of Symbiosis
Mutualism
Commensalism
Parasitism
Mutualism
• In Mutualism both species benefit from the
symbiotic partnership.
Commensalism
• Commensalism occurs when
one species benefits from a
relationship and the other
organism is neither harmed
nor does it benefit in any way.
Parasitism
• Parasitism occurs when one species
benefits at the expense of another
species. Parasites live on or inside the
host and obtain some or all of the nutrition
from the host.
Identify the type of Symbiotic
Relationship.
Commensalism
Mutualism
Parasitism
Ecosystem’s Carrying
Capacity
As a population grows, each individual gets a
smaller share of the resources in the area.
equilibrium is number of deaths in a population
equal to the number of births.
After a while, there are fewer births and more
deaths. Eventually, the number of births equals
the number of deaths.
When this happens, the habitat is said to have
reached its carrying capacity.
Carrying capacity is the maximum number of
individuals that an ecosystem can support.
Limiting Factors
Is an environmental factor that prevents an
increase in the number of organisms in a
population.
Examples of Abiotic
Limiting Factors:
Amounts of:
• sunlight
• water
• soil
• air
• storms
Examples of Biotic
Limiting Factors:
• competition among organisms
for resources
• presence of predators
• presence of disease-causing
organisms.
Sustainable Ecosystem