Transcript Population Ecology Power Point

POPULATION ECOLOGY
Population Density
• is a measurement of population
per unit area
Population
Total land area
What is this population density
per these unit areas?
10 m
1nm
What affects population growth?
• 1. Number of births.
• 2. Number of deaths.
• 3. Number of individuals that
enter or leave the population.
Exponential Growth
J curve
• Exponential Growth animation
Conditions for Exponential
Growth
• 1. plenty of food
• 2. plenty of space
• 3. protected from predators and
disease
Exponential Growth Videos
Bacteria Growth Video
• TeacherTube Videos - Bacterial Growth
• **BBC - Learning Zone Class Clips Bacterial growth – Biology
• Bacterial Culture
• (click on animation of bacterial culture)
• Bacterial Culture
• If the environment is optimum,
the two daughter cells may
divide into four in 20 minutes.
Oh my! 1, 2, 4, 8, 16, 32, 64...
Then why isn't the earth
covered with bacteria?
Logistic Growth
S curve
Logistic Growth (ani)
• At first the population increases,
then resources become
limited…growth at a slower rate.
Carrying Capacity
• Largest number of
individuals that an
environment can support.
Rabbits Over Time
INTERPRETING ECOLOGICAL DATA
• Graph 1: Rabbits Over Time
a. The graph
shows an S
(logistic)
Shaped growth
curve.
b. b. The carrying
capacity for
rabbits is ~65
c. During which
month were the
rabbits in
exponential
growth?June
Average Toe Length
INTERPRETING ECOLOGICAL DATA
• a. In 1800, about how many
people surveyed had a 3 cm
toe? ~58
• How many in 2000? ~10
b. The data shows the
*Stabilizing selection has
occurred?
c. In 2000, what is the average
toe length? ~4.5
• What is the average toe length
in 1800?
about the same, broader range
• #see next slide
•Graph 2:
Average Toe
Length
Mode of Natural Selection
INTERPRETING ECOLOGICAL DATA
• Graph 3: Mexico and US
• a. In Mexico, what
percentage of the
population is between 0-4
years of age? 16 In the
US? 7
• b. Which population is
growing the fastest?
Mexico
• c. Which age group has the
smallest number in both
countries? 80+
Tagging Geese
INTERPRETING ECOLOGICAL DATA
• Chart 4: Trapping Geese
• ecologists marked 10 geese
• a. Use the formula to calculate the
estimated number of geese in the area
studied? 60(10) / 6 = 100
b. This technique is called Mark &
Recapture
c. Supposing more of the geese found in
the trap had the mark, would the estimated
number of geese in the area be greater or
lesser? less (bottom number would be
greater in formula)
Trapping Geese
recaptured
YEAR
GEESE TRAPPED
# WITH MARK
1980
10
1
1981
15
1
1982
12
1
1983
8
0
1984
5
2
1985
10
1
Mushroom Plots
INTERPRETING ECOLOGICAL DATA
• Chart 5: Mushroom Plots
• She plots a 10 x 10 area and randomly
chooses 5 spots,
• a.Calculate the number of mushrooms
in the forest based on the grid data:
Average per grid = 3, 100 plots; total =
300
• b. This technique is called Random
Sampling
Snake and Mice Populations
The maximum number
of individuals a
habitat can support
is called the
Carrying Capacity.
Population Growth =
Mice Born – Mice Death
INTERPRETING ECOLOGICAL DATA
• Chart 6: Snakes & Mice (see next slide)
• a. During which year was the mouse
population at zero population growth?
2000, closest to zero
• b. What is the carrying capacity for
snakes ? 15
c. What is the carrying capacity for
mice? 600-620
• d. What is the rate of growth for mice
during 1970? +500 During 1980? -100
YEAR
SNAKES
MICE DIED
2
MICE
BORN
1000
1960
1970
10
800
300
1980
30
400
500
1990
15
600
550
2000
14
620
600
2001
15
640
580
200
Limiting Factors
• Density Dependent
large, dense
populations are
more strongly
affected than small,
less crowded ones.
• EXAMPLES:
Food
Predators
Water
Disease
Living space
• Density Independent
• Factors that can
affect a population
no matter what size
it is
• EXAMPLES:
Hurricane
• Forest fire
• Clear cutting
• Building dam
Density-Dependent Limiting
Factors
•
•
•
•
•
Competition
Predation
Parasitism
Disease
Living Space
Limited Food
Predation
DD or DI?
fire
predator
• DI
• DD
• DD
Density of
plants
DD or DI?
cannibalism
Cutting
trees
disease
• DD
• DI
• DD
LIMITING FACTORS
WORKSHEET:
Read Yellow Perch in Lake
Winnipeg
HUMAN POPULATION GROWTH
• http://www.gov.mb.ca/conservation/sustain
/limfac.pdf
• The world population is the population of
humans on the planet Earth. It is currently
estimated to be 6,874,700,000 by the
US Census Bureau.
Human Population
• How will the world population change in
the future?
• Is the
population
distributed
evenly
around the
earth?
Human Population
• Energy 365 Technology Basics: Population
Growth : Video : Discovery Channel
• Visuals: NOAA's nighttime lights of the
world data set
China’s One-Child Policy
• It officially restricts the number of
children married urban couples can
have to one, although it allows
exemptions for several cases, including
rural couples, ethnic minorities, and
parents without any siblings
themselves.[
计划生育政策
Indoor Air Pollution of Poorer
Countries
Access to safe water and
sanitation are two of the most
fundamental indicators of public
health.
Widespread HIV infection in subSaharan Africa is changing the
region's demographic structure
and impinging on its economic
performance.
Before the 19th century, world population grew
very slowly because high fertility was offset by
high mortality. Improvements in population
health, triggered partly by the industrial
revolution, ushered in a period of rapid
population growth.
Disease Can Even Jump Species
The Plague
Caterpillar Eating Maple Leaves
Lynx vs. Hare
Predator Prey Model
• Predator Prey
• Can change numbers of
rabbits and foxes over years
Clumped
Uniform
Random
Pattern of Distribution: RANDOM
Pattern of Districution:
CLUMPED
Pattern of Distribution: UNIFORM
“Mark and Recapture”
• Method used to estimate population size
• Total no. captured X no. marked
(total number recaptured with mark)
Capture-Mark-Recapture
Random Sampling
• Each member of the population has an
equal and known chance of being
selected.
•
http://www.cee.vt.edu/ewr/environmental/teach/smprimer/design/randanim.gif
Resources
Can be replaced or
be regenerated
Cannot be replenished
RENEWABLE RESOURCE
• A natural resource is a renewable
resource if it is replaced by natural
processes at a rate comparable or
faster than its rate of consumption
by humans.
• Geothermal
timber
• Water
leather
• Wind
solar
Geothermal Plant in Iceland
NONRENEWABLE RESOURCE
• Cannot be produced, grown, or
generated at a rate as fast as it is
used.
• Gasoline
coal
natural gas
“Sustainable
Development”
• Using natural
resources without
depleting them
Replant trees
•
Fighting poverty
Biomass energy
Harming our Resources
• Desertification- =productive land turned
into desert by over farming,
overgrazing
Harming our Resources
• Deforestation-loss of forests
Acid Rain
has a pH of
about 5.5.
• sulfur dioxide (SO2) and
nitrogen oxides (NOx) are the
primary causes of acid rain.
Sources of Acid Rain?
pH
ranges
SMOG
• Smoke + fog = smog
L.A.
BIODIVERSITY
Why is Biodiversity Necessary?
•The more bio-diverse
an ecosystem is, the
more likely it is to
survive.
Why is Biodiversity Necessary?
• For example, in a corn field with one
type of corn (not bio-diverse), if a
disease wiped out that corn, all
organisms living there would die.
Why is Biodiversity Necessary?
• In an ocean (very bio-diverse), if one
type of plant died, another kind could
fill its niche.
Species of Many Kinds Provide
us medicines, industrial
products, and foods
Drugs from
Nature
Biological Magnification
Concentrations
of harmful
substances
increase at
higher trophic
levels
DDT
• dichlorodiphenyltrichloroethane
is one of the most well-known
synthetic pesticides.
delousing
Used
19481972
Mosquito
fogger
Criticisms of DDT
-Decline in bird populations
(thin egg shells)
-Increases in cancer
-Slow growth of algae
-Retained in earthworms and
plankton – passed through
biological magnification
-Reproductive toxicity
-Poisoning
-Does not get through
human skin, but will
collect in fat if ingested
Banned 1972 Because
• 1. Caused cancer in Humans
• 2. Deleterious effect on freshwater
fish, estuary organisms, wild birds,
and other wildlife.
Rachel
Carson
spoke
against
DDT
Invasive Species
• Non-native plants or animals invading an
area
Invasive Species
• Zebra Mussels were carried in
on ships from Russia and
became abundant in the Great
Lakes.
Invasive Species
• Purple loosestrife
invades marshes
and lakeshores,
replacing cattails
and other wetland
plants.
• Kudzu – from
Japan to stop
erosion
KSU’s Black
Squirrels
• In February 1961, Larry Wooddell, the
superintendent of KSU's™ 500 acres, and
Biff Staples, a Davey Tree expert,
ventured to Ontario, Canada to obtain 10
cages with black squirrels. Both men
worked with the Canadian Wildlife Service
and American and Canadian Customs for
permission to move the squirrels.
Black Squirrels
• By 1964, the Kent Record-Courier
observed that there were up to 150
squirrels in the area.
Ozone Depletion
• Ozone (O3)
• Protects the
earth from UV
Banned CFC’s
• Chlorofluorocarbons in
aerosols
Break off an o
from O3
ANIMATIONS
• CFC and Ozone animation
• CFCs attacking O3
Global Warming
• Increase in the
average
temperature of the
Earth’s nearsurface air and
oceans
• Coastlines rise
Evidence of Global Warming
Sea Ice Melts.
Evidence of Global Warming
• NASA's Gravity Recovery and Climate
Experiment show Greenland lost 150 to
250 cubic kilometers (36 to 60 cubic miles)
of ice per year between 2002 and 2006,
while Antarctica lost about 152 cubic
kilometers (36 cubic miles) of ice between
2002 and 2005.
Evidence of Global Warming
• The carbon dioxide content of the Earth’s
oceans has been increasing since 1750,
and is currently increasing about 2 billion
tons per year. This has increased ocean
acidity by about 30 percent
Evidence of Global Warming
• Global temperatures have risen
Evidence of Global Warming
Evidence of Global Warming:
Glacial Retreat
Evidence of Global Warming:
More Frequent Hurricanes
Frequency of
Hurricanes.
Evidence of Global Warming:
Atmospheric Carbon Dioxide
Concentration. :
• Global sea level rose about 17
centimeters (6.7 inches) in the last
century. The rate in the last decade,
however, is nearly double that of the
last century.
Evidence of Global Warming
• The oceans have absorbed much of this
increased heat, with the top 700 meters
(about 2,300 feet) of ocean showing
warming of 0.302 degrees Fahrenheit
since 1969.