Habitat ecology

• What are the two main groups of factors determining species distribution?

  Abiotic and biotic factors
• What do abiotic factors include?

  Light intensity, water, nutrients, and temperature
• What do biotic factors include?

  Competition for resources, predators, and disease
• What equipment is needed for measuring species distribution along a gradient?

  • Quadrat
  • Transect (20m rope marked at 1m intervals)
  • Clipboard
  • Equipment to measure variable
• What is the first step in the method for measuring species distribution?

  Choose a site with an abiotic gradient
• How should the quadrat be placed on the transect?

  Bottom left corner on the mark every time
• How is percentage cover recorded in the quadrat?

  Count squares with half or more covered
• What should be measured at each coordinate along the transect?

  The independent variable, like light intensity
• What should be done with the collected data after the practical?

  • Plot a graph of percentage cover against the independent variable
  • Perform statistical tests: Spearman’s Rank, T-test, Chi Squared
• What does a correlation in the graph indicate?

  The effect of the variable on species distribution
• What is an important note about correlation?

  Correlation is not necessarily causation
• What are the risks associated with the practical?

  • Biohazard: Allergies, soil bacteria, contamination
  • Slippery surfaces: Slip hazard
• What safety precautions should be taken during the practical?

  • Wash hands after practical
  • Wear appropriate footwear; don’t run
• What should be done in case of a biohazard risk?

  Wash hands after practical
• What should be done in case of a slip hazard?

  Seek appropriate medical attention
• What is the length of the transect used in the method?

  20 meters
• What is the purpose of using a photometer in the method?

  To measure light intensity at each coordinate
• How can the results of the practical be influenced?

  By a range of factors affecting the results