population ecology
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Population Ecology. Population Density Number of individuals of a species per unit at a given time Population dispersion (spacing) Clumped dispersion Uniform dispersion Random dispersion. Dispersion of individuals with a population. Dispersion in a sand pine population in Florida. - PowerPoint PPT PresentationTRANSCRIPT
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition CHAPTER 51 Introduction to Ecology: Population Ecology
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition Solomon • Berg • Martin
Population Ecology
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition CHAPTER 51 Introduction to Ecology: Population Ecology
Population DensityNumber of individuals of a species per unit at a given time
Population dispersion (spacing)• Clumped dispersion• Uniform dispersion• Random dispersion
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition CHAPTER 51 Introduction to Ecology: Population Ecology
Dispersion of individuals with a
population
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition CHAPTER 51 Introduction to Ecology: Population Ecology
Dispersion in a sand pine population in Florida
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition CHAPTER 51 Introduction to Ecology: Population Ecology
Four factors that produce changes in population size:
1. Natality: Birth Rate2. Mortality: Death Rate3. Immigration: Entering a territory4. Emigration: Leaving a territory
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition CHAPTER 51 Introduction to Ecology: Population Ecology
Carrying capacity (K) is the largest population that can be maintained
–Exponential population growth (J-shaped curve)
–Logistic population curve (S-shaped curve)
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition CHAPTER 51 Introduction to Ecology: Population Ecology
Exponential population growth
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition CHAPTER 51 Introduction to Ecology: Population Ecology
Carrying capacity and population growth
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition CHAPTER 51 Introduction to Ecology: Population Ecology
Density-dependent factors:• Factors that regulate population
growth by affecting a large proportion of the population as population rises
• Examples include predation, disease, and competition
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition CHAPTER 51 Introduction to Ecology: Population Ecology
Density-dependent factors and negative feedback
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition CHAPTER 51 Introduction to Ecology: Population Ecology
Density-independent factors:• Factors that limit population growth
but are not influenced by changes in population density
• Examples include hurricanes, blizzards, floods, volcanic eruptions, drought, etc
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition CHAPTER 51 Introduction to Ecology: Population Ecology
Human Population Growth• World population reached 6.3 billion
in 2003. Today is almost 7.0 billion• Per capita growth rate has declined
from peak in 1965 of about 2% per year to 1.3%
• Scientists predict zero population growth by the end of the 21st century
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition CHAPTER 51 Introduction to Ecology: Population Ecology
Human population growth
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition CHAPTER 51 Introduction to Ecology: Population Ecology
Population characteristics• Highly developed countries
–Low birth rate, low infant mortality, low fertility rate, long life expectancies, and high GPP
• Developing countries–High birth rate, high infant mortality,
high fertility rate, short life expectancies, and low GNI PPP
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition CHAPTER 51 Introduction to Ecology: Population Ecology
Comparison of 2003 population data in developed and developing countries
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition CHAPTER 51 Introduction to Ecology: Population Ecology
Birth and death rates in Mexico, 1900–2000
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition CHAPTER 51 Introduction to Ecology: Population Ecology
• Age structure influences dynamics• Young age structure causes a
positive population growth momentum as large pre-reproductive age group matures
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition CHAPTER 51 Introduction to Ecology: Population Ecology
Age structure diagramsAge structure diagrams
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition CHAPTER 51 Introduction to Ecology: Population Ecology
• Developing countries tend to have over-population which degrades the environment. (Mexico, Brazil, India, China etc)
• Developed countries tend to have over-consumption which degrades the environment. (USA, Germany, France, Britain, etc)