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Applying Population Ecology: The Human Population

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Presentation on theme: "Applying Population Ecology: The Human Population"— Presentation transcript:

1 Applying Population Ecology: The Human Population
Chapter 5 Applying the principles of population dynamics and sustainability to the growth of the human population

2 Current Population Trends
World population = 6.4 billion (6,400,000) in 2004 Doubled since 1963 = 3.2 billion In 2050 could be 7.2 – 10.6 billion Amplifies all environmental problems Largest increase expected in developing countries (approximately 97%) Decreasing in some developed countries Rate actually decreased between , but the population has still doubled from 3.2 –6.4 billion

3 Rate = 80 million new people/year
+ New York City every month + Germany every year + United States every 3.7 years

4 Washington State Population
Our jobs as scientists have certainly changed from those days of when our early explorers ventured into our state. And they will keep changing with our growing population, as the pressures on our resources keep growing as well.

5 Population projections
For the next 20 years

6 Factors Affecting Human Population Size
Population change equation Population change = (Births + Immigration) – (Deaths + Emigration) Crude birth rate = births per 1000 people in population per year Crude death rate = deaths per 1000 people in population per year

7 Varies between regions
Total Fertility Rate (TFR) - Number of children a woman has during her lifetime, averaged for population. same as biotic potential (r) Replacement Level Fertility - Number of children needed to replace everyone in the population. Varies between regions 2.1 with low infant mortality 2.5 with high infant mortality Zero Population Growth - Birth rate equals death rate.

8 Sex Ratio - Age Distribution
Sex Ratio- Relative number of males and females in a population Age Distribution - Number of individuals of each age in a population Together they tell how a population will grow

9 Population Age Structure
Developing Countries Developed Countries Growth is determined by teenagers – the population wave of the future. 30% of pop’n <15 years = 1.9 billion more into reproductive years.


11 Population Trend Comparisons
Developed Countries Low infant mortality rate Life expectancy 77 years Total fertility rate = 2.0 21% population <15 12% population >65 Per capita GDP = $36,110 Developing Countries High infant mortality rate Life expectancy 52 years Total fertility rate = 5.7 44% population <15 3% population >65 Per capita GDP = $800

12 Human Population Issue
Several factors determine the impact of a society on natural resources. Population size Population density Degree of technological development Demography - Study of populations and their characteristics. Larger ecological footprint in U.S. than in developing countries. Why?

13 Environmental Impact

14 The fertility rates have significantly fallen since 1950.

15 Factors Affecting Birth Rates and Total Fertility Rates
Children in Labor Force Cost of raising and educating children Availability of pension systems Urbanization Education and employment for women Infant mortality rate Average marrying age Abortion Availability of birth control

16 Major social factor determining family size is the role of women in society.
Early marriages foster high fertility rates. Lack of education opportunities for women reduces their options. When level of education increases, fertility rates fall. The most important factor is the ability of women to control the size of their family. Access to birth control is key.


18 United States Population Picture
US population has a post-war baby boom period, significantly affecting pop. trends. 20 yr period following WWII By 2030, 20% of US pop will be over 65

19 U.S. Birth Rates:





24 US Immigration rates Immigration accounts for 41% of pop’n growth in the U.S. Should we have tougher immigration laws to help preserve our natural resources?

25 Demographic Transition
As countries become industrialized, death rates, then birth rates decline.

26 Case Study: Slowing Population Growth in India
Generally disappointing results 1952 – 400 million 2004 – 1.2 billion Poor planning Bureaucratic inefficiency Low status of women Extreme poverty Lack of support Culture – Indian women believe you need children to work, care for when they are old.

27 Case Study: Slowing Population Growth in China
Economic incentives (food, large pensions, better housing, salary bonuses, free schooling) Free medical care Free sterilization Locally administered Very intrusive and coercive Problem with parents selecting for males Fertility rate decreased from 5.7 in 1972 to 1.7 in 2004.


29 Cutting Global Population Growth
Family planning Improve health care Elevate the status of women Increase education Involve men in parenting Reduce poverty Sustainability

30 Global Megacities Number of large cities growing. World’s urban population will increase from 3.1 billion to 5 billion from

31 US metropolitan areas

32 Undesirable Impacts of Urban Sprawl

33 Loss of crop land, forest
land, and wetlands

34 Fragmenting fish and wildlife habitats

35 Increased impervious surfaces means more flooding

36 And soil erosion

37 And a larger ecological footprint

38 Beneficial is all a matter of one’s

39 Urban Land-Use Planning and Control
Property taxes Zoning Smart growth Urban growth boundary Greenbelts

40 Growth Management Act 1990 The GMA requires state and local governments to manage Washington’s growth by identifying and protecting critical areas and natural resource lands, designating urban growth areas, preparing comprehensive plans and implementing them through capital investments and development regulations. GMA is passed to help protect areas critical for natural resources by concentrating growth in urban areas

41 Public voices concerns at GMA hearing - Sounding off: Land division and road upgrades among issues addressed at four-hour hearing

42 Transportation Mass transit vs. automobile
What makes one or the other feasible? Why is most of the US developed around cars? When did it happen? Where does mass transit work? What are the pros and cons to each?

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