Download Interactions - ScienceGeek.net

Interactions
in
Ecosystems
Habitat
• All of the biotic and abiotic
factors in the area where an
organism lives
Lion habitat
Ecological Niche
• All of the physical, chemical, and
biological factors that a species needs
to survive, stay healthy, and reproduce
– Food
– Abiotic conditions
– Behavior
Competitive Exclusion
• When two species are competing for the
same resources, one species will be
better suited to the niche, and the
other species will be pushed into
another niche or become extinct
• Invasive species may outcompete
organisms that are native to a particular
region
Predation
• The process by which one species
captures and feeds upon another
– Heterotrophs can prey on autotrophs and
other heterotrophs
Predator – Prey Cycles
• Prey
outnumber
predators
• Increasing
numbers of
prey promote
increases in
predator
populations
Symbiosis
• A close ecological relationship
between two or more organisms of
different species that live in direct
contact with one another
–Mutualism
–Commensalism
–Parasitism
Mutualism
• An interspecies interaction in which
both species benefit
– Flowers and pollinating insects
– Humans and intestinal E. coli
– Clown fish and anemones
Commensalism
• A relationship between two organisms in
which one receives an ecological benefit
from another, while the other neither
benefits or is harmed
• Many ecologists believe that
commensalism is rare, and that most
such relationships are probably subtle
mutualism or parasitism
Parasitism
• A relationship in which one species
benefits while the other is harmed.
• Many parasites have complex lifecycles
involving more than one host
Seen “Alien” ?
The Parasitic Life Cycle of the Tse-Tse
Fly
Tapeworm lifecycle