sampaling plants.

Question 1

define stable community.

Answer 1

all species and environmental factors are in balance so that population sizes remain fairly constant.

Question 2

define distribution.

Answer 2

where an organism is found.

Question 3

what does distribution depend on?

Answer 3

environmental factors.

Question 4

define quadrats.

Answer 4

square frames, usually 1 m squared, made from wood or plastic. organsims underneath usually plants can be identified and counted. can also be used for slow moving animlas eg: snails and slugs.

Question 5

how do you estimate populations: step- 1.

Answer 5

find the area of the quadrat.

Question 6

how do you estimate populations: step- 2.

Answer 6

find the area of the site.

Question 7

how do you estimate populations: step- 3 and what is it known as.

Answer 7

divide the area of the site by the area of the quadrat- multiplication factor.

Question 8

how do you estimate populations: step- 4.

Answer 8

place the quadrat randomly.

Question 9

how do you estimate populations: step- 5.

Answer 9

count and record the number of organsims.

Question 10

how do you estimate populations: step- 6.

Answer 10

take at least 10 samples.

Question 11

how do you estimate populations: step- 7.

Answer 11

work out the mean number of organisms in each quadrat.

Question 12

how do you estimate populations: step- 8.

Answer 12

multiply up to estimate the total number in the site.

Question 13

how do you improve the accuracy?

Answer 13

• bigger quatrat.
• more quadrats.
• random sampliling.

Question 14

how would this factor improve the accuracy: bigger the quadrat?

Answer 14

more likely to include organsims.

Question 15

how would this factor improve the accuracy: more quadrats?

Answer 15

more representitive.

Question 16

how would this factor improve the accuracy: random sampliling?

Answer 16

avoid biases in results and over estimate that would come from ‘selecting’areas where organsims are.