adaptations, interdependence and competition

• Ecosystem


  The interaction between a community of living organisms and their environment
• Community


  All the organisms that live in a habitat (plants and animals)
• Population


  All of the members of a single species that live within a geographical area
• Species


  A type of organism that is the basic unit of classification. Individuals of different species are not able to interbreed successfully
• Levels of organisation within an ecosystem

  • Producer
  • Primary consumer
  • Secondary consumer
  • Tertiary consumer
• Producer


  Plants and algae, which photosynthesise
• Primary consumer


  Herbivores, which eat producers
• Secondary consumer


  Carnivores, which eat primary consumers
• Tertiary consumer


  Carnivores, which eat secondary consumers
• Interdependence


  The fact that all organisms that live in an ecosystem depend upon each other, for food, protection, shelter, etc, in order to survive
• Food chain


  A sequence (usually shown as a diagram) of feeding relationships between organisms, showing which organisms eat what and the movement of energy through trophic levels
• Photosynthesis


  A chemical process used by plants to make glucose and oxygen from carbon dioxide and water, using light energy. Oxygen is produced as a by-product of photosynthesis. Algae subsumed within plants and some bacteria are also photosynthetic
• Competition


  Photosynthesising plants and algae in an ecosystem compete for light, space, water and minerals from the soil. Animals in an ecosystem compete for food, mates and their territory
• Intraspecific competition


  The competition between organisms within the same species
• Stable community


  A community in which the size of the populations of all species remain relatively constant over time
• Quadrat

  A square frame of known area used for sampling the abundance and distribution of slow or non-moving organisms.
• Abiotic factors affecting communities

  • Light intensity
  • Temperature
  • Soil pH and mineral content
  • Moisture levels
  • Availability of oxygen and carbon dioxide
• biotic factors affecting communities

  • new predators
  • availability of food
  • new pathogens
  • interspecific competition
• abundance


  the abundance is the number of organisms in an ecosystem and their distribution is affected by abiotic factors. These are factors that are non-living.
• competition in animals

  • food
  • territory
  • mates
• quadrats - random sampling

  1. Divide the area to be sampled into a grid using measuring tapes placed at right angles to each other.
  2. Use random numbers to generate coordinates within the grid on which to place the quadrats.
  3. Place a quadrat at each coordinate.
  4. Count the numbers/estimate percentage cover of each species in each quadrat.
  5. Use a key to identify each species.
  6. Record results in a table.
  7. Calculate the average of each species.
• quadrats - a belt transect

  The belt transect method is used when there is a gradual change from one side of a habitat to another, like the change in light between the outer edges of a forest to the centre.
• procedure of a belt transect

  1. Extend a measuring tape from one side of the habitat to another.
  2. Place a quadrat at 0m on the tape.
  3. Count the numbers/estimate percentage cover of each species.
  4. Use a key to identify each species.
  5. Record results in a table.
  6. Move the quadrat along the measuring tape.
  7. Repeat step 3-5 at regular intervals along the measuring tape.
  8. Continue until the full length of the measuring tape has been sampled.
  9. Calculate the average of each species.
  10. A bar chart can be drawn to show the data obtained.
• what do plants compete for?

  light, space, water and mineral ions from the soil
• surviving and reproducing

  • plants need light, co2, water, oxygen and mineral ions to produce glucose to give them the energy they need to survive
  • animals need food from other living organisms, water and oxygen
• plant adaptations

  structural - having characteristics that can hurt animals so they wont get preyed on

  behavioural - epiphytes in rainforests live high above the ground to collect water + nutrients from the air

  physiological - sweet/strong scented nectar in order for pollen dispersal
• animal adaptations


  herbivores -have teeth for grinding up plant cells

  carnivores - have teeth for tearing flesh

  they also have adaptations to attract mates
• extemophiles

  they have adaptations that enable them to live in environments with extreme conditions of salt, temperature and salty water
• animals in cold climates

  the smaller the surface area to volume ratio the easier it is to reduce the transfer of energy to the environment and minimise cooling. this explains why so many artic mammals are relatively large