Ecology

• Abiotic Factors


  The non-living parts of the environment that can

  often have a major influence on living organisms

  • Light intensity
  • temperature
  • moist levels
  • soil pH and mineral content
  • wind intensity and direction
  • CO2 level of plants
  • Oxygen Levels for Aquatic Animals
• Biotic Factors


  What can affect the community are:

  • availability for food
  • new predators arriving
  • new pathogens
  • one species outcompeting another so the numbers are no longer sufficient to breed.
• Light 


  • Plants grow only when there is enough light
  • Photosynthesis
  • The length of a day is the main stimulus that plants use to detect the time of the year.
  • Germination of seeds, flowering and growth occur at specific times of the year and can only happen when conditions are suitable.
• Measuring Light intensity


  • Light meters can be used to measure light intensity. The meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.
  • Errors can be made when measuring light intensity by accidentally shading the light meter. The reliability of the results can be checked by taking many samples.
• Temperature 


  Temperature affects the rate of growth and reproduction in living organisms.

  • Has an effect on biological processes.
  • Most organisms function best within a specific range of temperatures.
  • Temperatures vary between night and day, and also vary during seasons.
  • The temperature of the air can be measured with a thermometer. The temperature of the soil can be measured with a temperature probe.
• Moisture Levels


  -Water makes up 70% of the weight of most living things.

  -Essential chemical reactions take place in water.

  -Water transports dissolved substances inside and between cells.

  Vegetation is dense where water is plentiful.

  The distribution of animals is determined by the type and variety of vegetation.

  Water is recycled in and between ecosystems.
• Soil Analysis


  Soil is important for plant growth as it provides water and mineral salts and holds the plant firmly in the ground

  The type of soil will determine the type of plant that will grow there

  Mineral content, pH, moisture, particle size and composition all need to be done back in the lab.

  To do this we need to collect a soil sample from each area we visit. The sample will need to be sealed in a plastic bag until we perform tests on it.
• Wind intensity and direction

  • Moving air
  • Wind is greater at high altitudes which can effect the growth of trees
  • Wind assists in the pollination of flowers and distribution of fruits and seeds

  Some plants adaptations to survive in wind:

  Sunken stomata

  Needle like leaves

  Thick waxy cuticles
• Atmospheric oxygen and Carbon Dioxide

  Atmospheric gases like oxygen, nitrogen and carbon dioxide:

  All organisms require oxygen for respiration.

  Carbon dioxide is used by green plants to make food by the process of photosynthesis.