Copyright Pearson Prentice Hall 6-1 A Changing Landscape Copyright Pearson Prentice Hall
Population and growth patterns The size of a population is always changing. Four factors affect the size of a population. -immigration -births -emigration -deaths Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Population growth is based on available resources. Exponential growth is a rapid population increase due to an abundance of resources. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Logistic growth is due to a population facing limited resources. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Carrying capacity is the maximum number of individuals in a population that the environment can support. A population crash is a dramatic decline in the size of a population over a short period of time. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Ecological factors limit population growth. A limiting factor is something that keeps the size of a population down. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Density-dependent limiting factors are affected by the number of individuals in a given area. Predation Competition Parasitism and disease Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Density-independent limiting factors limit a population’s growth regardless of the density. Unusual weather Natural disasters Human activities Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Earth as an Island Earth as an Island All organisms on Earth share a limited resource base and depend on it for their long-term survival. To protect these resources, we need to understand how humans interact with the biosphere. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Human Activities What types of human activities can affect the biosphere? Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Human Activities Some human activities that affect the biosphere include: hunting and gathering agriculture industry urban development Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Agriculture The Green Revolution The green revolution was an effort in the mid-twentieth century to increase global food production through modern plant breeding and agricultural techniques. Over the last 50 years, the green revolution has helped world food production double. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Agriculture Challenges for the Future While increasing world food supplies, modern agriculture has created ecological challenges. For example: Monoculture leads to problems with insect pests and diseases. Finding enough water for irrigation is difficult. Copyright Pearson Prentice Hall
Industrial Growth and Urban Development Human society and its impact on the biosphere were transformed by the Industrial Revolution, which added machines and factories to civilization. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall
Industrial Growth and Urban Development The energy to power machinery comes mostly from fossil fuels—coal, oil, and natural gas. Suburban growth consumes farmland and stresses native plants and animals. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall 6-1 Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall 6-1 Today, the most important source of environmental change on the planet is the green revolution. wild plants. humans. abiotic factors. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall 6-1 The practice of planting a single crop in the same place year after year is called uniculture. monoculture. the green revolution. plant breeding. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall 6-1 One problem with modern agriculture is that chemical fertilizers don’t work. chemical pesticides can damage beneficial insects. it has decreased world food production. new varieties of plants require little water. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall 6-1 One impact of early hunting and gathering groups in North America might have been changing the climate from very cold to much warmer. the elimination of forests. a mass extinction of large mammals about 12,000 years ago. the development of large civilizations in Central and South America. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall 6-1 Most of the energy for industry comes from a. the sun. nuclear power plants. moving water. fossil fuels. Copyright Pearson Prentice Hall
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