11.3 Sampling Techniques

Question 1

Which techniques may be used to sample animals?

Answer 1

• POOTER
  
  • Device used to capture insects.
• SWEEP NETS
  
  • Used to catch insects in long grass.
• PITFALL TRAP
  
  • Used to catch small, crawling invertebrates.
• TREE BEATING
  
  • Tree is shaken, species in tree fall onto large white cloth.
• KICK SAMPLING
  
  • River bed/bank kicked to disturb substrate. Downstream net catches dislodged species.

Question 2

How can a quadrat be used to sample plants?

Answer 2

• POINT QUADRAT
  
  • Frame containing horizontal bar.
  • Pin pushed through, plant species touching the pin are recorded.
  • Pin is moved along set intervals & process repeated.
• FRAME QUADRAT
  
  • Square frame divided into grid.
  • Type & number of species in each grid is recorded.

Question 3

To collect the most valid, representative sample of the abundance of organisms in an area, quadrats should be used alongside a [random/non-random] sampling technique.

Answer 3

random

Question 4

To study how the presence & distribution of organisms across an area varies, quadrats should be with a ____.

Answer 4

line transect / belt transect

Question 5

In which ways can a frame quadrat be used to sample plant populations?

Answer 5

• DENSITY
  
  • count number of plants present in 1m x 1m quadrat, indicates number of plants per m²
• FREQUENCY
  
  • count number of squares in which species is present.
• PERCENTAGE COVER
  
  • estimate of percentage of area covered by a species within the quadrat.

Question 6

What are abiotic factors?

Answer 6

non-living conditions

in a habitat

Question 7

What are examples of abiotic factors?

Answer 7

• Wind speed
• Light intensity
• Humidity
• pH
• Temperature

Question 8

What are the advantages of using sensors for measuring abiotic factors?

Answer 8

• Can detect rapid changes
• High precision
• Data can be stored & tracked on computer