We can get a good idea of which plants are present by observing a number of small sample areas within our study area. To do this we use a square frame called quadrat. It is placed randomly in the study area and the types of plant within the quadrat are listed. The quadrat is used ten times to give a more accurate record of which plants are present in the entire study area.

The data that is collected using a quadrat call also be used to estimate how much of a particular type of plant there is within a study area.