Investigating Ecosystems

Question 1

Describe how the distribution and abundance of organisms can be measured using a point quadrat

Answer 1

• a point quadrat is a horizontal bar on two legs with a series of holes at set intervals along its length
• point quadrats are placed on the ground at random points within the area you’re investigating
• points are dropped through the holes in the frame and every plant that each pin touches is recorded
• the number of individuals of each species is recorded in each quadrat
• the percentage cover of a species can also be measured by calculating the number of times a pin has touched a species as a percentage of the total pins dropped

Question 2

Describe how the distribution and abundance of organisms can be measured using a line transect

Answer 2

A tape measure is placed along the transect and the species that touch the tape measure are recorded

Question 3

Describe how the distribution and abundance of organisms can be measured using a belt transect

Answer 3

• interrupted belt transect - at regular intervals a quadrat is placed next to the line and species are tallied
• continuous belt transect - data is collected along the transect using frame quadrats placed next to each other

Question 4

Describe how the distribution and abundance of organisms can be measured using a frame quadrat

Answer 4

• a frame quadrat is a square frame divided into a grid of smaller squares
• they’re placed on the ground at random points within the area you’re investigating - can be done by selecting random coordinates
• the number of individuals of each species is recorded in each quadrat
• the percentage cover can also be measured by counting how much of the quadrat is covered by the species