23.5 - Measuring The Distribution And Abundance Of Organisms

Question 1

How to measure distribution?

Answer 1

• Line transact: laying a line along the ground and taking samples at regular intervals - systematic sampling
• systematic sampling > random sampling because can see affect clearly of abiotic factors

Question 2

Why would the abundance of organisms fluctuate?

Answer 2

• Immigration + births to increase population

- Emigration + deaths to decrease population

Question 3

How to measure plant abundance?

Answer 3

• use quadrants randomly in an area
• count number of individuals within the Quadrat
• Number of individuals in sample / area of sample

Question 4

How to measure animal abundance

Answer 4

Capture-Mark-Release-Recapture

1) Capture as many individuals in a sample area
2) Mark/tag each individual
3) Release animals and give time for redistribution
4) Recapture individuals in same sample area
5) Record data of marked and unmarked
6) use equation

(Individuals in 1st sample x 2nd sample) / no of recaptured individuals