Quadrats Fieldwork

Question 1

What are quadrats?

Answer 1

Square frames that can be used to estimate population sizes.

Question 2

How do you calculate the mean?

Answer 2

Add up all the values and then divide by the number of recordings that have been made.

Question 3

How do you calculate the median?

Answer 3

The middle value in a numerically ordered series.

Question 4

How do we calculate the mode?

Answer 4

The mode is the most common value in a series.

Question 5

What is the formula to calculate population?

Answer 5

population = number counter x (total survey area/area sampled)

Question 6

How do we use quadrats to estimate a population size?

Answer 6

1. Divide the habitat up into a series of quadrat- sized cells.
2. Randomly select a given number of cells, then go out into the habitat and place the quadrat in the positions.
3. To evaluate the quadrat contents, either count the number of individual organisms of interest or record the percentage of the quadrat taken by an organism (e.g grass)
4. The samples from the quadrat are used to estimate the total population in a given area:

population = number of individuals counted x (total survey area/area sampled)