ecosystems

• Carbon cycle


  • Carbon dioxide in atmosphere
  • Carbon dioxide in oceans
  • Decomposers
  • Decay
  • Respiration
  • Photosynthesis
  • Fossil fuels
  • Combustion
  • Planting trees
  • Soil carbon sinks
• Symbiosis


  Mutually beneficial relationship between two organisms of different species
• Symbiotic relationships

  • Ants and aphids
  • Parasitism
• Crop rotation


  1. Changing what a field is used for each year

  2. Giving one field a break to gain nutrients again

  3. Adding chemical fertilizers to provide plants with nutrients for healthy growth
• Fertilizers (NPK) are added to the soil to provide plants with molecules for growth and healthy development
• Excessive use of fertilizers can be bad (pollution)
• Preventing decay

  1. Airtight conditions (reduce oxygen flow)

  2. Refrigeration

  3. Smoking/salting/pickling

  4. Adding sugars
• Encouraging decay


  1. Warm conditions

  2. Oxygen for respiration

  3. Bacteria/fungi
• Aerobic respiration


  Glucose + Oxygen → Carbon dioxide + Water
• Anaerobic respiration


  Glucose → Ethanol + Carbon dioxide
• Symbiotic relationship


  Plants get nitrogen, bacteria get carbohydrates and a habitat
• Nitrogen is essential for the formation of amino acids in proteins
• Root hair cells of plants absorb nitrates from the soil by active transport
• Eutrophication


  1. Excessive nutrients from fertilizers end up in rivers

  2. Algae growth covers water and prevents sunlight

  3. Photosynthesis stops, oxygen levels drop

  4. Biodiversity decreases
• Biodiversity


  The enormous variety of life on Earth
• Fish farming


  • Reduces carbon emissions
  • Renewable
  • Increases food security
  • Reduces biodiversity
  • Sustainability issues
• Ways to reduce food poverty

  • Buy locally (reduced carbon footprint)
  • Eat less meat (vegan/vegetarian)
  • Eat sustainable food
• More meat eaten as population and general wealth increased
• Advantages of fish farming


  • Protects fish, monitored water quality, improved quality of life
• Disadvantages of fish farming

  • Disease, overcrowding, sustainability issues
• Biological control of invasive species


  1. Promote growth of native species to outcompete invasive species

  2. Introduce predators to control invasive species
• Accidental introduction of invasive species can harm native ecosystems
• Photosynthesis is required for life
• Respiration increases as microorganisms break down grass, releasing water vapor
• Fungi and bacteria are mainly responsible for decay
• As oxygen levels drop, the rate of decay drops because oxygen is needed for respiration