Transcript Interactions within Communities

Interactions within
Communities
SBI4U
Ecological Niches
• Community
• All populations in a given ecosystem
at a specific time
• Types of niches
• Ecological niche
• The role of an organism within the
biotic and abiotic factors of the
environment
• Fundamental niche
• The theoretical role an organism can
reach within the environment
• Realized niche
• The actual role an organism can
achieve due to limiting factors in the
environment
Types of Interactions
• Interspecific Competition
• Interactions between individuals of
different species for common
resources
• Intraspecific Competition
• Interactions between individuals of
the same species for common
resources
Coevolution
• Process in which one species evolves in response to the
evolution of another species.
• Eg. Hummingbird beaks that have adapted ‘evolved’ over time to
have the shape of the plant/flower the pollinate.
Types of Interactions
• Types of interactions
• Competition
• Interactions that may be harmful to both
species
• Predation/Herbivory
• Beneficial to one species, loss of life for the
other
• Symbiosis
• Parasitism
• Beneficial to one species, harmful but not
lethal for the other
• Mutualism
• Beneficial to both species
• Commensalism
• Beneficial to one species but does not affect
the other
Competition
• Interference competition
• Different species aggressively
fighting over resources
• Exploitative competition
• One species out consuming the other
for resources
• Resource partitioning
• Avoidance of competition by
occupying different ecological niches
Predation
• A predator-prey relationship is
when one species feeds on
another and the relationship
can affect the population of
both species
• Some species have developed
defense mechanisms
• Camouflage, chemical defence,
behavioural defense, mimicry,
spines & armour.
• E.g. horns, hooks, spines,
needles, as well as chemical
defences, also hiding and
camouflage
Symbiosis
• Mutualism
• Obligatory mutualism is when both species
need each other for survival
• Commensalism
• A relationship where one species benefits and
the other neither benefits or is harmed
• Parasitism
• Microparasites
• Microscopic parasites (plasmodium)
• Macroparasites
• Larger parasites (tapeworm)
• Endoparasites
• Parasites that feed inside the body
• Ectoparasites
• Parasites that feed outside the body
• Social parasites
• Parasites that manipulate other organisms to
complete their life cycle (cowbird)
How are these species influencing each other?
How are these species influencing each other?
How are these species influencing each other?
How are these species influencing each other?
Interspecific Interactions
SPECIES A
Positive (+)
Positive (+) MUTUALISM
-cowbirds + cows
Neutral (0)
COMMENSALISM
-barnacles on whales
Negative (-) PREDATION or
PARASITISM
- only the predator or the
parasite benefit
SPECIES B
Neutral (0)
Negative(-)
NEUTRALISM
- probably nonexistent
AMENSALISM COMPETITION
- bread mould
- both species have
produces penicillin decreased fitness
that kills bacteria
Disruption of Equilibrium
• Things tend to stay as they are
• Natural disasters and the introduction of
invading species
• Purple loosestrife
• Rabbits in Australia
• Ecological disturbances that that change the
equilibrium
Credits
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http://commons.wikimedia.org/wiki/File:Edge-of-a-wood.JPG
http://commons.wikimedia.org/wiki/File:CulexNil.jpg
http://commons.wikimedia.org/wiki/File:Water_Buffalo_fight.jpg
http://commons.wikimedia.org/wiki/File:Wolves_and_bones.jpg
http://commons.wikimedia.org/wiki/File:Common_clownfish_curves_dnsmpl.jpg
http://commons.wikimedia.org/wiki/File:Jenga.gif
http://commons.wikimedia.org/wiki/File:Homework_-_vector_maths.jpg
http://commons.wikimedia.org/wiki/File:Red-billed_oxpeckers.jpg
http://commons.wikimedia.org/wiki/File:Hummingbird_Texas.jpg