23.5 Measuring the distribution and abundance of organisms

• Define the term abundance

  The number of individuals of one species in a particular area
• Define the term distribution

  Where a particular species is within the area you are investigating
• How could you ensure that your sampling method is random?

  Use a random number generator for coordinates
• What is a transect?

  A transect is a line across an area of land
• Name 2 types of quadrat

  Frame quadrat and point quadrat
• How could you capture fish?

  Use a net
• How could you capture insects?

  Use a sweep net
• How could you capture butterflies?

  Make a pitfall trap
• Name 2 pieces of apparatus needed for calculating percentage cover of plant species

  Frame quadrat and measuring tape(transect) (could have species index)
• How can distribution of organisms be measured?

  Using line or belt transect - non-random, systematic sampling
• Should measuring distribution be random or non-random?

  Non-random
• Give the equation to calculate the estimated plant abundance within an area of 1m2.

  (number of individuals in sample) ÷ (area of sample in m2)
• What method is used to find the animal abundance in an area?

  Capture-mark-release-recapture technique
• Name an assumption you make when you use the mark-release-recapture method

  Marking the organism does not impact its survival / no migration / organisms randomly distribute after first release