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Using Quadrats

• The distribution of an organism is the places where an organism can be found. Differences in distribution between organisms is largely down to environmental factors, in which organisms need certain conditions to survive and thrive in.
• There are two ways of measuring the distribution of organisms:
• Measure how common an organism is in two sample areas using quadrats
• See how distribution changes across an area by placing quadrats along a transect
• Both these give quantitative data
• Quadrats are simply a square frame which encloses a given area. To compare organism distribution, follow these steps:
• Place a 1m^2 quadrat on a random point in the first sample area
• Count all the organisms in the quadrat
• Repeat steps 1 to 2 as many times as possible
• Work out a mean number of organisms in the first sample area
• Repeat steps 1 to 4 in the second sample area
• Compare the 2 means

Using transects

• You can also use lines called transects to help find out about how organisms are distributed across an area:
• Mark out a line in the area you want to study using a tape measure
• Collect data along the line
• Count all the organisms youre interested in that are touching the line
• You could also collect data using quadrats, for example, placing them together or at intervals