Download Population Dynamics

4/17/2015
(7)
Science concepts. The student knows the
relationship between carrying capacity & changes
in populations and ecosystems.
The student is expected to:
(A) relate carrying capacity to population
dynamics.
(B) Calculate birth rates & exponential
growth of populations.
(C) Analyze & predict the effects of nonrenewable resource depletion.
(D) Analyze & make predictions about the
impact on populations of
geographic locales
due to disease, birth & death rates, urbanization, &
natural events such as migration and
seasonal changes.
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Levels of Biological Organization
Biosphere
Biome
Ecosystem
Community
Population
Organism Species
Population
Group of individuals of the same species
occupying the same area at the same time
Population
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Population density is the number of
individuals that live in a defined area.
• Population density is a measurement of the number of
individuals living in a defined space.
• Ex: 100 coyotes per square mile
We took a sampling of deer & counted 200 deer over 10
square miles. What would be this deer population’s
density?
200/10 = 20 deer per square mile
Geographic DISTRIBUTION shows what
regions of the world organisms are found
in.
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Geographic DISPERSION of a population shows
how individuals in a population are spaced.
Clumped
dispersion
• Population dispersion refers to
how a population is spread in
an area.
Uniform
dispersion
Random
dispersion
• There are three types of dispersion.
– clumped
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• There are three types of dispersion.
– uniform
• There are three types of dispersion.
– random
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Test Review
Test on Wednesday
Study:
Journal notes
Texas Ecoregions (Pineywoods – Edwards Plateau)
Quizzes
Chapter 14 worksheets
Population Growth Rate
•
•
•
•
+ Natality = births (b)
- Mortality = deaths (d)
+ Immigration = moving in (i)
- Emigration = moving out (e)
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Population Growth
Recruitment
Losses
Natality
Immigration
Mortality
Emigration
(birth rate)
(in)
(death rate)
(out)
Population Graph
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Carrying Capacity (K)
• The largest number of individuals that a given
environment can support
Exponential Growth
• When individuals reproduce at a constant rate
• Under ideal conditions with unlimited
resources
• J-shaped
curve
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Logistic Growth
• When growth slows or stops after a period of
exponential growth
• As resources become less available
• S-shaped
curve
Limits to Growth
• Limiting Factor
• Factor that causes population growth
to decrease
Write the following on the separate colors:
• Density-Dependent Limiting Factor
– Depends on population size
• Density-Independent Limiting Factor
– Affects all populations in similar ways, regardless
of population size
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Limiting Factors
Density
Dependent
Competition
Predation
(Hunting)
Density
Independent
Unusual Weather
Natural Disasters
Parasitism
Seasonal Cycles
Disease
Human Activity –
damming rivers,
clear-cutting,
Biotic Potential
• The size that a population would reach if all
offspring were to survive
– Ideal conditions
– No limiting factors
• Populations vary in their capacity for growth.
When environmental factors are optimal,
populations grow.
Maximum Natality – Minimum Mortality
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Predator Prey Relationship
Age Structure
• Distribution of individuals by age
– Pre-reproductive
– Reproductive
– Post-reproductive
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K-Selected
• Stable populations
• Remain at/near Carrying Capacity = Logistic Growth
• Late successional species = Climax Species
Life Strategies
R-Selected
• HIGH population growth rates = Exponential Growth
(biotic potential)
• Population greatly fluctuates
above/below Carrying Capacity
• Early successional species = Pioneer Species
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General
Characteristics
R-Selected
K-Selected
Organism
Size
Small
Large
Low
High
(little or no parental care)
(much parental care)
# of Offspring Produced
Many (quantity)
Few (quality)
Timing of Maturation
(Reproductive Age)
Early
Late
Life Expectancy
Short
Long
Exponential
Logistic
(J curve)
(S curve)
Reproductive Rates
Type of Growth Curve
Niche
Generalists
Specialists
(adapt quickly to changes)
(stable habitats)
Pests (invasive)
T/E Species
Species Type
K-Selected
R-Selected
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