Transcript Changes to Populations

 Take your Population Lab out for me to check
 Ecological Community
 Groups of interacting organisms
 Pond Community (lilly pads, frogs, fish, snakes, elodea, etc)
 Forest Community (trees, shrubs, squirrels, birds, deer, etc)
 Coral Reef Community (coral, sponges, sharks, fish, algae, etc)
 Habitat
 Area where community of organisms live.
 Requires 4 components:
 Food, water, cover, space
 Ecosystem
 Interactions of communities of organisms with each other
and their habitat.
 Increase Population
 1) Birth
 2) Immigration (entering a population)
 Decrease Population
 3) Death
 4) Emigration (leaving a population)
 See if you can create an equation using these 4
terms for Population Growth, Population
Decrease, Population Stability
 Populations Increase:
 When Immigration + Births > Death + Emigration
 Population Remains Stable:
 When Immigration + Births = Death + Emigration:
 Populations Decrease:
 When Immigration + Births < Death + Emigration
 Anything that
prevents the
growth of a
population
 What would
happen without
limiting factors?
 The
maximum
population a
species can
maintain in a
certain area
without
damaging the
ecosystem.
 29 introduced in
1944
 More than
6,000 by 1963
 Down to 42 by
1966
 Territorial
Animals need
a large
amount of
space.
 Loss of
Habitat
causes the
decline of
many species.
Who took my towel?
 Loss of trees/wooden posts caused a huge decline
 Between 1935-1985 numbers declined by 90%
Answer- Food, water, cover, and space.
 Leads to death via
dehydration,
starvation
 Some animals will
emigrate
 Organisms that rely
on one type of food
are severely affected
 Temperature
changes can
affect plants
and animals
 Floods and
storms can
cause death &
destruction of
habitat
 Mosquitoes
breed in
standing
water
 Rainfall
creates
puddles of
standing
water
Impact of Temperature
Rise on Robusta Coffee
in Uganda.
*Developing countries,
whose economies often
rely heavily on one or two
agricultural products, are
especially vulnerable to
climate change.
*This graphic shows that
With an increase of only
2 degrees Celsius, there
would be a dramatic
decrease in the amount
of land suitable for
growing Robusta coffee
in Uganda.
 Protection from predators
 Protection from weather
Some organisms prefer edge,
because they need the cover
and specific species of plants
that grow there to feed on…
Other species have their
habitats Fragmented by roads,
fields, farms, etc.
 Ruffed Grouse- Requires
brushy forests for cover and
food. Most of Pa’s forest were
logged (cut down) 80 to 100
years ago.
 They grew into brushy forest
allowing grouse populations
to increase.
 Forests are now maturing
reducing cover and food
causing populations to
decline.
 Land development has also
reduced populations
 An increase in the number of predators to an area
will impact prey species.
 Predicted that in one year
house cats kill 1 billion
songbirds! WATCH THIS
 Spread quickly through high density populations
 Can devastate populations with low genetic diversity
 Mosquito
born disease
 5,697 crows
reported
dead in NYS
in 1999
 Fungus that has killed over one million bats
 90-100% of some species of hibernating bats are in
danger of being killed.
 Plants that cannot tolerate too much or too little light
can be affected
 Aspen Pine Poplar = intolerant,
will dominate young forests
 Beech, Fir, Hemlock, Maple =
tolerant will dominate older forests
 Close
proximity to
humans
causes some
species to
emigrate
 Other species
thrive
 Think of an example where an organism does not
have enough limiting factors.
 What is the organism, how does this affect the
habitat around that organism?
 Limiting factors lead to competition among
organisms for available resources
 A loss in a limiting factor can contribute to a decline
in populations
 Increased due to exotic species
Exotic Species
 Watch this…
http://www.youtube.com/watch?v=b98JmQ0Cc3k&fe
ature=related
 What is the solution? Is there one? Use the debate
form I give you with directions to come up with
solutions…if there are any…if we need them.