Field Investigations RPA

Question 1

Random sampling Method to estimate total population of daisies in field

Answer 1

1) place one 20m tape measure along edge of one side of field and one 20m tape measure along edge of perpendicular side
2) add counters numbered 1 to 20 to 2 bags
3) person 1 randomly picks a counter from their counter bag and person 2 randomly picks one from their counter bag
4) person 1 moves along tape measure according to number picked e.g 5= 5m and person 2 does the same (picks counter from their bag and moves along other tape measure)
5) person 3 places 1m squared quadrat where the 2 distances meet and count umber of daisies
6) person 1 and 2 return 2 counters to bag and whole process is repeated 9 more times to get a total of 10 different samples of daisies
7) estimate total number of daisies in field by doing:
total area of quadrants = 10 x area of quadrat = 10x 1= 10
Total number of daisies counted by adding up number counted from each of 10 quadrants
Divide total area of field by total area of all qudrats e.g 20x20=400 so 400/ 10= 40
Multiply number of daises by this number to get estimated number of daisies in whole area of field

Question 2

Random sampling Method to estimate total population of daisies in field

Answer 2

1) place one 20m tape measure along edge of one side of field and one 20m tape measure along edge of perpendicular side
2) add counters numbered 1 to 20 to 2 bags
3) person 1 randomly picks a counter from their counter bag and person 2 randomly picks one from their counter bag
4) person 1 moves along tape measure according to number picked e.g 5= 5m and person 2 does the same (picks counter from their bag and moves along other tape measure)
5) person 3 places 1m squared quadrat where the 2 distances meet and count umber of daisies
6) person 1 and 2 return 2 counters to bag and whole process is repeated 9 more times to get a total of 10 different samples of daisies
7) estimate total number of daisies in field by doing:
total area of quadrants = 10 x area of quadrat = 10x 1= 10
Total number of daisies counted by adding up number counted from each of 10 quadrants
Divide total area of field by total area of all qudrats e.g 20x20=400 so 400/ 10= 40
Multiply number of daises by this number to get estimated number of daisies in whole area of field

Question 3

Why ransom sampling method is only estimate

Answer 3

Some areas of field may have much higher/ lower number of daisies than others but qudrat may only be dropped in areas of low daises/ areas of high daises

Question 4

Method used to investigate affect of certain factor on distribution of plant species e.g light intensity

Answer 4

1) place a tape measure from the base of the tree going out towards an open area of ground (to create transect line)
2) randomly drop quadrat at 0 mark of tape measure and count number of daisies in qudrat
3) repeat every 1m up to the end of the transect line
4) repeat investigation at least 4 more times to calculate mean number of species at each point
5) plot a graph comparing number of plants against light intensity (to ensure the light intensity increases further away from the tree use a light meter to measure light intensity at each metre along the transect)