POPULATIONS AND ENVIRONMENT

Population Equilibrium – Investigating Populations

Population Equilibrium – Investigating Populations

Studying ecology is best done within the natural habitat of an organism. However, this poses a number of problems, for example habitats tend to be very big, a population might be made up of a large number of organisms, and some organisms are very elusive and hard to find. That’s why there are a number of fieldwork techniques to help deal with these issues.

Sampling

Studying a whole ecosystem would be impossible. There’s why it make more sense to take a sample. Depending on the objectives of the investigation there are two ways of sampling.

  • Random sampling: this is used when you want to take a representative sample of an area. To achieve this, an area is measured out using tape. Random numbers are generated either from tables or a computer and the numbers used as co-ordinates. The random numbers can also be used to represent the angle and distance from a starting central point. You want to aim for a large number of samples, or at least 10, to minimise the chances of skewed sample and allow for any anomalies. You should also aim to sample at least 2% of a whole area. For this kind of sampling you could use a quadrat.
  • Systematic sampling: this is for when a particular pattern is under investigation and involves you choosing where you want to take samples. For this you could use a line or belt transect.