Biodiversity sampling methods

Question 1

What is random sampling?

Answer 1

Sampling where each individual has an equal chance of being picked. Often done using a marked out grid and a random number generator to sample from random coordinates.

Question 2

What is opportunistic sampling?

Answer 2

Non random sampling where the most conveniently available organisms are sampled.
Unreliable but easy and fast.

Question 3

What is stratified sampling?

Answer 3

The population is separated into subgroups (strata) and then random sampling is used within each strata.

Question 4

What is stratified sampling used for?

Answer 4

Used to see the differences between different groups in a population e.g: male/female

Question 5

What is systematic sampling in biology?

Answer 5

The use of a line or belt transect to see how the abundance of species changes.

Question 6

What is systematic sampling used for?

Answer 6

Used to see the differences in distribution and abundance of species between different areas of a habitat.

Question 7

What is a pooter used for?

Answer 7

To collect individual insects.

Question 8

What is a sweep net used for?

Answer 8

To catch lots of insects from one area.

Question 9

What is a pitfall trap used for?

Answer 9

To collect a sample over time with little maintenance.

Question 10

What is tree beating used for?

Answer 10

To collect a sample from a whole tree quickly.

Question 11

What is kick sampling used for?

Answer 11

To sample organisms living in rivers/water.

Question 12

What is a point quadrat?

Answer 12

A horizontal bar with regularly spaced pins.

Question 13

What is a point quadrat used for?

Answer 13

To sample plants over an area of ground.

Question 14

What is a frame quadrat used for?

Answer 14

To sample species in an area across a transect.

Question 15

What is the concept behind capture mark release?

Answer 15

Mark captured individuals, release back into the community, then take another sample.
The more marked individuals recaptured -> the smaller the population.

Question 16

What are examples of abiotic factors?

How are they measured?

Answer 16

Wind speed (anemometer)
Light intensity (light meter)
Temperature (temperature probe)
Humidity (humidity sensor)
pH (pH probe)
Oxygen content (dissolved oxygen probe)

Question 17

What are 3 ways of calculating abundance of a species?

Answer 17

Abundance scale
Count each one
Percentage cover

Question 18

What is the abundance (ACFOR) scale, and when is it used?

Answer 18

Abundant, Common, Frequent, Occasional, Rare
This is a subjective, qualitative method which is used because it is quick, and easily transferable to different situations.

Question 19

How is percentage cover used to calculate abundance?

Answer 19

Split quadrat into smaller squares and calculate percentage cover (take an average of multiple quadrats)

Question 20

What is Simpson’s index of biodiversity used to represent?

Answer 20

Species biodiversity, it is an index of both species richness and evenness.

Question 21

What does a value of Simpson’s index close to one represent?

Answer 21

The habitat shows high species richness and evenness, the habitat has high species biodiversity.

Question 22

What does a value of Simpson’s index close to zero represent?

Answer 22

The habitat shows low species richness and evenness (low species biodiversity).

Question 23

What is the significance of low species biodiversity in a habitat?

Answer 23

Environmental change may have drastic consequences as the community is less able to adapt to new pressures.

Question 24

What is the significance of greater species evenness?

Answer 24

The community is more stable.

The community can better cope with abiotic and biotic changes.

Question 25

What is a tullgren funnel used for?

Answer 25

To extract living organisms (particularly insects) from a sample of soil.