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Published byBrianne Cummings Modified over 9 years ago
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POPULATION ECOLOGY: AN INTRODUCTION
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I. CHARACTERISTICS OF POPULATIONS A. Density and Abundance – Abundance refers to the number of individuals, N.
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I. CHARACTERISTICS OF POPULATIONS A. Density and Abundance – Abundance refers to the number of individuals, N. – Density refers to the number of individuals per unit area
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I. CHARACTERISTICS OF POPULATIONS A. Density and Abundance – Relation to body size
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I. CHARACTERISTICS OF POPULATIONS A. Density and Abundance l large species occur at lower densities l relationship exists with metabolic rate:
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I. CHARACTERISTICS OF POPULATIONS A. Density and Abundance B. Vital Rates
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I. CHARACTERISTICS OF POPULATIONS A. Density and Abundance B. Vital Rates – Fertility rate (# female live births/female/unit time) (also natality and fecundity)
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I. CHARACTERISTICS OF POPULATIONS A. Density and Abundance B. Vital Rates – Fertility rate – Mortality rate (deaths/indiv/time)
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I. CHARACTERISTICS OF POPULATIONS A. Density and Abundance B. Vital Rates – Fertility rate – Mortality rate – Immigration rate (in/indiv/time)
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I. CHARACTERISTICS OF POPULATIONS A. Density and Abundance B. Vital Rates – Fertility rate – Mortality rate – Immigration rate – Emigration rate (out/indiv/time)
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I. CHARACTERISTICS OF POPULATIONS A. Density and Abundance B. Vital Rates C. Age Structure – proportion of individuals of various ages
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I. CHARACTERISTICS OF POPULATIONS A. Density and Abundance B. Vital Rates C. Age Structure D. Sex Ratio – ratio of males to females – example 60:40
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II. DENSITY-INDEPENDENT POPULATION GROWTH A. Growth in a Constant Environment with Unlimited Resources – population doubles monthly – N after 4 months = ?
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A. Growth in a Constant Environment with Unlimited Resources time N 0 3 1 6 2 12 3 24 4 48 after 4 months
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II. DENSITY-INDEPENDENT POPULATION GROWTH A. Growth in a Constant Environment with Unlimited Resources – finite rate of change ( ) = 6/3 = 12/6 = 24/12 = 48/24 = 2
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II. DENSITY-INDEPENDENT POPULATION GROWTH Geometric model:
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II. DENSITY-INDEPENDENT POPULATION GROWTH Exponential model:
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II. DENSITY-INDEPENDENT POPULATION GROWTH Growth rate is independent of N
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II. DENSITY-INDEPENDENT POPULATION GROWTH – Intrinsic rate of increase
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II. DENSITY-INDEPENDENT POPULATION GROWTH B. The Importance of Considering Environmental Variation – Red deer and spring temperature
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II. DENSITY-INDEPENDENT POPULATION GROWTH B. The Importance of Considering Environmental Variation – Cotton rats on the northern fringe
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II. DENSITY-INDEPENDENT POPULATION GROWTH B. Importance of Environmental Variation SpeciesSpring Captures Cotton rats22% Prairie voles99% White-footed mice 83% Deer mice 80% Harvest mice 66%
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