Download Fundamental niche - Gull Lake Community Schools

Shaping Communities
5.3
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Shaping Communities
5.3
 Niche  a species way of life, or role/function the species plays
in its environment… “occupation”
 How does “it” use the physical environment?
 How does “it” interact with other species?
 Others…
 Fundamental niche: range of conditions and resources a
species can tolerate and potentially use (no influence of
competition, predation, etc.)… very broad
 Realized niche: range of resources it actually uses (influenced
by competition)… narrow, more specific
 generalists (organisms with broad niches)
vs
specialists (organisms with narrow niches)
 Ex. koala and opossum (which is which?)
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Competition for resources 
 Winner/Loser: competitive exclusion (one
species eliminating another through
competition).

Ex. invasive species vs. native species
 Coexisting: division of resources (aka
“resource partitioning”); fundamental niche
vs. realized niche.

Ex. fig. 9 pg. 114
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Ecosystem Resiliency (stability)
predation, keystone species, & biodiversity
 Predation can reduce the effects of competition among
species
 Ex. mussels (good competitors for space in ocean)
--sea stars eat mussels
--when sea stars are present, a variety of species are
able to live in the same area that the mussels live
(intertidal zone)
 Ex. sea otters (eat sea urchins)
--sea urchins eat kelp
--kelp forests provide habitat for many aquatic animals
--predict what would happen if the sea otters were
removed from the ecosystem
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 Keystone species: one that is critical to
an ecosystem b/c it affects the survival and
number of many other species in its
community (ex. sea otters and sea stars
from previous slide).
 Biodiversity…# of species w/i a
community.


higher biodiversity  increased resiliency
(“healthy” ecosystem).
predation helps increase biodiversity
…explain how this is possible.
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