Download Chapter 1 ‐ Section 2 ‐ Populations A. Competition—two or more

Chapter 1 ‐ Section 2 ‐ Populations
A. Competition—two or more organisms seek the same resource at the same time
1. Competition for food, living space, or other resources can limit the population’s size.
2. Competition is usually most intense between members of the same species.
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B. Population size—indicates whether a population is healthy and growing
1. Population density—the size of a population that occupies a specific area
2. Two ways to measure the size of a wildlife population
a. Trap‐mark‐release method
b. Sample count method
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3. Elements that affect population size
a. Limiting factor—any living or nonliving feature that restricts the number of individuals in a population
b. Carrying capacity—the largest number of individuals of one species that an ecosystem can support
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3. Elements that affect population size
c. Biotic potential—the highest rate of reproduction under ideal conditions
a. Limiting factor—any living or nonliving feature that restricts the number of individuals in a population
d. Birth and death rates
b. Carrying capacity—the largest number of individuals of e. Movement of organisms into or out of an area
one species that an ecosystem can support
C. Exponential growth—the larger a population becomes, the c. Biotic potential—the highest rate of reproduction under faster it grows
ideal conditions
d. Birth and death rates
e. Movement of organisms into or out of an area
C. Exponential growth—the larger a population becomes, the faster it grows
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1. Do any of the tanks contain too many crickets? Could you make the population density of the tree tanks equal by moving crickets from one tank to another? If so, which tank would you move crickets into? The population densities of the three tanks are: 1) 250 crickets/m2, 2) 187.5 crickets/m2, and 3) 210 crickets/m2. Tank 1 has too many crickets. You might try putting some of the extra crickets into tank 2, because it has a lower population density. Tank 3 has the maximum population density allowed.
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2. Wild crickets living in a field have a population density of 2.4 crickets/m2. If the field's area is 250 m2, what is the approximate size of the cricket population? Why would the population density of crickets in a field be lower than the population density of crickets in a tank?
Multiply the population density by the area: 2 2
250 m x 2.4 crickets/m = 600 crickets
The field's population density would be less than the tank's because the crickets have more space and less competition.
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Test your knowledge of section 2 in a self‐check quiz!
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Attachments
LS0492AA.avi