15: Research Methods

Question 1

What is Simpsons diversity index?

Answer 1

It is used to assess the variety and abundance of species in an area. D = N(N-1)/sum of n(n-1)

N = total number of individuals of all species
n = number of individuals of a particular species

Question 2

What different ecological techniques are there for sampling organisms?

Answer 2

• quadrats
• nets
• suber samplers
• Plankton net
• colonisation media
• pitfall traps
• beating trays
• light traps
• tullgren funnel
• suction samplers

Question 3

What are the limitations of a surber sampler?

Answer 3

• they can only be used where water flow is fast

- escape around the sides

Question 4

What are the limitations of the plankton net?

Answer 4

-Large mesh size may not catch small organisms, small mesh size may get clogged by plankton

Question 5

What are the limitation of sweep nets?

Answer 5

Mobile insects may escape

Question 6

What are the limitations of pitfall traps?

Answer 6

• only suface organisms
• more mobile species are more likely to be caught
• some species may avoid or escape the trap