Transcript Limits to growth - Sonoma Valley High School

Lecture 5-2
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W/B: what is the limiting
nutrient?
Many factors can limit
population growth.
They can be either
density- dependent
or density-independent
China
Habitat loss has reduced the bamboo
forests the Pandas eat.
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Become important
when population
density is high- the #
of individuals per a
certain area.
#1Competition:
for food, water,
sunlight, space can
happen within a
species and between
species
P/S: what will the puffins
compete for?
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W/B: what year had the most
wolves? What year had the most
moose?
Increases in the prey
population are
followed by increases
in the predator
population.
If the predator dies,
the prey numbers will
rise again.
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Parasites act similar to
predators, taking
nourishment at the
expense their hosts.
They weaken the host,
causing disease or
death
The parasitic wasp lays its eggs on
the moth larvae. The wasp larvae
feed on their host as they grow.
Parasitized moth larvae
(hornworm)
Parasitic wasp
Sphinx moth
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P/S: what tolerance levels were
exceeded for these species?
Affect all populations
in an area in similar
ways.
#1 Extreme weather
Storms, drought,
extreme cold can cause
many populations to
crash
Agriculture
Damming rivers
Cutting forests
Cities and streets
Pollution
 Humans have caused
rapid changes to
ecosystems, adversely
affecting many species.
3 gorges dam, China
2000 and 2006 (satellite
image)
W/B: what % of the land in this picture is ‘natural’?
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Today’s talk was about…….
I already knew about………..
I just learned that………
I wonder why…………