Practical- measuring population size in and habitat

• Feeding relationships between organisms in an ecosystem can be seen in food chains
• Sampling allows us to measure the abundance and distribution of species in an ecosystem
• To measure species richness on the school field in areas where grass is regularly and irregularly cut:

  • Choose a starting point in an area where the grass is often cut
  • Use random numbers to generate coordinates for the first quadrat
  • Count the number of different plant species within the quadrat
  • Repeat the process 15 times with different random numbers
  • Compare results by calculating the mean for each location
• Results:

  • On the cut school field: total of 25 plant species and a mean of 1.7 per quadrat
  • On the uncut school field: total of 52 plant species and a mean of 3.5 per quadrat
• Conclusions:

  • The mean number of plant species in the cut school field is lower than in the uncut school field
  • Greater species richness is observed in uncut areas of the school field
• Limitations in drawing conclusions:

  • Only 15 quadrats were used, more quadrats would provide more confidence in the conclusions