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The number of individuals per unit area or volume (extremely hard to determine)
Density
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The pattern of spacing among individuals within the boundaries of the population
Dispersion
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Individuals aggregate in patches- influenced by resources availability and behavior (most common)
Clumped dispersion
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Individuals are evenly spaced- influenced by social interactions such as territoriality
Uniform dispersion
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The position of each individual is independent of other individuals (least common)
Random dispersion
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The study of birth rates, death rates, age distributions, and the sizes of populations (how births and deaths change population sizes over time)
Demography
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An age-specific summary of the survival pattern of a population- best constructed by following the fate of a cohort from birth until they are dead
Life tables
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A group of individuals of the same age
Cohort
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A graphical plot of the numbers of surviving individuals at each age in a population
Survivorship curve
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What is the maximum population size that a particular environment can support?
Carrying capacity (K)
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How does carrying capacity affect population growth?
When N=K, the population stops growing
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What is the population increase under legalized conditions- results in a J-shaped curve- cannot be sustained
Exponential growth
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What includes the carrying capacity- results in an S-shaped curve- fits few real populations but it is useful for estimating population growth
Logistic growth
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What calculates the total productive land needed for each person to survive in a sustainable world?
Ecological footprint concept
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The average ecological footprint for everyone on planet Earth is currently 3 what?
hectares
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The current ecological footprint for a person in the US is 10 what?
hectares
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How do density-dependent factors regulate population growth?
- Morality factor whose influence increases with the density of the population
- ex. predation, parasitism, disease, and competition
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What are density independent factors?
- Morality factors whose influence is not affected by population size or density
- ex. weather, drought, floods, fires
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What do age-structure pyramids show us about current and future population growth?
The show us where the most people are at different ages (relative number of individuals of each defined age group)
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