10.3.3 Human population and Habitat Destruction

• What is a population in ecological terms?

  A group of organisms of one species, living in the same area, at the same time
• What is a community in ecology?

  All of the populations of different species in an ecosystem
• How is an ecosystem defined?

  A unit containing the community of organisms and their environment, interacting together
• Why have human populations increased?

  Due to improved medical care, clean water, sewage treatments, vaccinations, improved housing, food storage, and modern food production methods
• What are some factors contributing to the increase in human populations?

  • Improved medical care/medicine/drugs and antibiotics
  • Clean or treated water
  • Sewage treatments
  • Vaccinations
  • Improved housing conditions
  • Improved food storage/transport/availability
  • Modern food production methods

  
• What is the relationship between human population growth and food demand?

  More people means more demand for food
• What are some modern food production methods that have increased agricultural productivity?

  Efficient use of machinery, inorganic fertilizers, pesticides, selective breeding, and monoculture
• What are the impacts of using inorganic fertilizers in agriculture?

  • Increased yields
  • Can lead to eutrophication
• What is monoculture in agriculture?


  Growing just one single crop in large fields
• What is intensive livestock production?

  A farming method where large numbers of livestock, such as chickens, are kept in a small area
• What are the advantages and disadvantages of intensive livestock production?

  Advantages:

  • Low costs for buildings

  
  

  Disadvantages:

  • Poor welfare of animals
  • Easy spread of disease
  • Regular use of antibiotics leading to resistance
  • Waste and sewage pollution in waterways

  
• What are some impacts of increasing human populations?

  Overcrowding, lack of access to clean water, rapid fossil fuel use, increased pollution, food shortages, and habitat destruction
• Why are habitats destroyed?

  • More land needed for crop growth
  • Hedges removed to make fields larger
  • Land needed for resource extraction
  • Pollution damages aquatic habitats
• What are the impacts of deforestation?

  Soil erosion, reduction in soil fertility, flooding and landslides, increased carbon dioxide levels, climate changes, and loss of habitats leading to extinction
• What are the consequences of soil erosion due to deforestation?

  • Loss of topsoil
  • Decreased agricultural productivity
  • Increased sedimentation in waterways
• How does deforestation contribute to climate change?

  • Increases carbon dioxide levels in the atmosphere
  • Reduces the number of trees that can absorb CO2