Ecology

• Habitat


  The environment in which an organism lives
• Population


  The total number of organisms of the same species living in the same geographical area
• Community


  The populations of all the different species that live in the same habitat
• Ecosystem


  Both the biotic and abiotic parts of an environment and how they interact
• Biotic and abiotic factors

  • Biotic: living
  • Abiotic: non-living
• Biotic factors affecting a community

  • Availability of food
  • Arrival of a new predator
  • Competition between species
  • New pathogens
• Abiotic factors affecting a community

  • Light intensity
  • Temperature
  • Water
  • pH and mineral content of soil
  • Wind intensity and direction
  • Carbon dioxide levels
  • Oxygen levels
• Levels of organisation


  • Photosynthetic organisms (producers)
  • Primary consumers
  • Secondary consumers
  • Tertiary consumers
• Predators and prey


  • Predators: consumers that kill and eat other animals
  • Prey: animals that are eaten
• Sampling organisms


  1. Random sampling

  2. Use a quadrat

  3. Estimate total population
• Limiting factors can be measured using a transect line and quadrats
• The carbon cycle


  1. Carbon dioxide in atmosphere

  2. Photosynthesis

  3. Respiration

  4. Combustion

  5. Decomposition

  6. Fossil fuel formation
• The water cycle


  1. Evaporation

  2. Condensation

  3. Precipitation

  4. Transpiration

  5. Uptake by plants and animals
• Biodiversity


  The variety of all the different species of organisms on Earth
• High biodiversity makes an ecosystem more stable
• Humans are having a negative effect on biodiversity through activities like deforestation
• Types of pollution


  • Water pollution
  • Air pollution
  • Land pollution
• Waste from human activities is reducing biodiversity
• Peat bogs and peatlands contain large amounts of trapped carbon
• Destruction of peat bogs releases carbon dioxide and reduces biodiversity
• Deforestation reduces photosynthesis and releases carbon dioxide, contributing to global warming
• Global warming is caused by human activities that release greenhouse gases like carbon dioxide and methane
• Consequences of global warming

  • Loss of habitats
  • Shifts in species distributions
  • Changes in plant growth patterns
• Ways to maintain biodiversity

  • Breeding programmes for endangered species
  • Habitat protection and regeneration
  • Preserving field margins and hedgerows
  • Reducing deforestation and emissions
  • Recycling resources