sampling methods revision (quadrats) mock revision 2022

Question 1

pooters collect…

Answer 1

• ground insects

- bottom of tree

Question 2

pooters are…

Answer 2

• jars that have a bung sealing the top of it, with two tubes running through the bung, long tube and short tube.

Question 3

how are pooters used?

Answer 3

• the long tube is placed over the insect on the ground above the insect.
• suck on the shorter tube and the insect is then sucked into the jar and collected.

Question 4

how are pooters useful for sampling?

Answer 4

• once all insects from the 2/however many sampling areas are collected the amount of insects can be compared.

Question 5

Pitfall traps collect…

Answer 5

• ground insects, range from beetles to snails.

Question 6

pitfall traps are…

Answer 6

• containers that are placed in a hole within the ground

- they have slanted sides and the top is partially open

Question 7

how are pitfall traps used?

Answer 7

• leave the trap overnight
• insects will walk/ fall into the trap and wont be able to escape as the sides are slanted
• next day look and count the amount of insects were found in the 1st sampling area
• repeat in another sampling area and then compare.

Question 8

Sweep nets collect…

Answer 8

• insects
• flies/ aphids
• spiders

Question 9

sweep nets are used in…

Answer 9

• tall grass

Question 10

how are sweep nets used?

Answer 10

• the net is swept through the tall grass
• insects are collected and then counted
• repeat in 2nd sampling area and then compare.

Question 11

pond net collects…

Answer 11

• insects

- water snails

Question 12

how are pond nets used?

Answer 12

• swept under water
• number of insects are counted
• used in another sampling area, compare

Question 13

Quadrats collect…

Answer 13

• insects, ground normally

Question 14

what is a quadrat?

Answer 14

• 1m^2 frame that is placed randomly within a nm^2 area.

Question 15

how are quadrats placed randomly?

Answer 15

• use random number generator to figure out coordinates and place the quadrat accordingly within the sampling area.

Question 16

how are quadrats used?

Answer 16

• count organisms within the quadrat
• repeat a certain amount of times to figure out the mean
  mean = total organisms / number of quadrats
  compare mean from other sampling area

Question 17

Estimating population size (quadrat)

Answer 17

• figure out a mean from quadrat sampling

- multiply the mean by the sampling area

Question 18

estimating pop size example
“ mean of organisms found within the quadrats is 4, the size of the sampling area is 20m^2 what is the estimated population size?”

Answer 18

4x20= 80

Question 19

capture - recapture method…

Answer 19

• capture a sample of the population
• mark the sample and then release them
• capture another sample
• count the number of marked organisms
• estimate the population size with the following calculation =

population size = (number 1st sample x 2nd)/ marked organisms

Question 20

capture recapture example Q
“ 30 woodlice are captured and marked, then another sample of 35 woodlice are recaptured, only 5 are marked what is the estimated population size?”

Answer 20

(30x35) / 5 = 210 woodlice