Transcript Human Population Growth

Warm-up
What is one fact about your biome you
remember from the research on your
biome?
What if humans suddenly
went extinct?
 https://www.youtube.com/watch?v=7ZPK
w9fKhD0
Succession intro activity
 What would happen if the SAHS football
field was abandoned?
 Draw pictures (using color) to show what
the field might look like in the future…10
years…25…50…100 years down the
road.
Ch. 3 Communities &
Biomes
Succession
 Series of predictable changes
that occurs in a community over
time
Primary Succession
 The 1st stage
 On land where there are no
living organisms.
 Pioneer Species: 1st species to
populate the area
Secondary Succession
 When a disturbance changes
the existing community, things
must grow again
 Ex. Land is cleared for
farming, then abandoned,
trees begin to grow again
Biomes
 Complex of terrestrial
community that covers a
large area
 Has a certain soil & climate
 Has particular plant & animals
Warm-Up
An uncut lawn becomes a meadow and
eventually a forest. This process is an
example of ___________.
A.
B.
C.
D.
Primary Succession
Secondary Succession
Limiting Factor
Tundra
Biome Presentations
• Respect every group.
• I will deduct points from your entire group
if you talk or interrupt other presentations.
• Write one fact from each presentation to
turn in.
• Relax (not all of you) and have fun while
you are PRESENTING but take notes
while you watch.
Ch. 4:
Populations
Characteristics of
Populations
 Geographic
Distribution
 Density
 Growth rate
Factors that Affect
Population Growth
 # of Births
 # of Deaths
 # of individuals that enter or leave the
population.
Exponential Growth
 Individuals
reproduce at a
constant rate
 Unlimited
growth
 J shaped curve
Logistic Growth
 As resources become less available, the growth
of a population slows or stops
 Carrying capacity: The largest number of
individuals that an environment can support.
 S shaped curve
Carrying capacity
Time (hours)
Concept Map
Section
5-1
Population
Growth
can be
Logistic
growth
Exponential
growth
characterized by
No limits on
growth
Unlimited
resources
represented by
Constant
growth rate
J-shaped
curve
characterized by
Limits on
growth
which cause a
Falling
growth rate
represented by
S-shaped
curve
Limiting Factors
 A factor that
causes population
growth to
decrease.
 Nutrients,
competition,
predation,
parasitism, water,
humans
Density Dependent
Factors
 Depend on population size
 Competition, predation, parasitism,
disease
How do increases and
decreases in the moose
population affect the wolf
population?
60
2400
50
2000
40
1600
30
1200
20
800
10
400
0
1955
1960
1965
1970
1975
Moose
1980
Wolves
1985
1990
1995
Density Independent
Factors
 Affect all populations in similar ways
(do not depend on size)
 Weather, Seasons, Natural Disasters,
Human Activities
Human Population Growth
 Until about 500 years ago, the world’s
human population remained fairly stable.
Then, as advances in medicine,
agriculture, and technology occurred, the
human population began growing very
rapidly. Today, the world’s human
population is greater than 6 billion
people, and it continues to grow, but at a
slower rate.
Human Population Growth
Industrial
Revolution
begins
Agriculture
begins
Plowing
and
irrigation
Bubonic
plague
Age Distribution
U.S. Population
Males
Rwandan Population
Females
Males
Females
 The human population is increasing by about
1.4% each year. If the population is 6 billion
(6,000,000,000) this year. How large will the
population be next year?
 6,000,000,000 X 0.014 = 84,000,000 people,
so the population would be 6,084,000,000
people.
 If the human population continues to grow at a
rate of 1.4 percent per year, the population
would double in size (to 12 billion people) in
only 51 years!
What effect might this increase in
population have on the environment
and on other people?
 What will happen when humans reach their
carrying capacity on Earth?
 What do you think the carrying capacity of
humans on the Earth is?