Required Practical Activity 9 - Measure the population size of a common species in a habitat. Use sampling techniques to investigate the effect of a factor on the distribution of this species

Question 1

What is used to work out the distribution and abundance os species in an ecosystem?

Answer 1

• to work out the distribution and abundance os species in an ecosystem, tools called transects and quadrats are used
• can then process this information, by calculating the mean, mode and median and then drawing a graph

Question 2

Method for random sampling:

Answer 2

1. Choose habitat you’re measuring and find it’s total area
2. Carefully place quadrant randomly in habitat (get random coordinate generator)
3. Repeat many times at random places around habitat and then calculate mean of number of certain plant Im quadrant
4. Multiply average number of daisies in each quadrant by number of quadrants you can fit in the area = estimate of how many daises are in the area
5. Calculate the area of the field - what is 10%?
6. Area of each square
7. Choose the coordinates for your quadrat
8. Count the daisies in each quadrat
9. Mean number of daises per quadrat
10. Estimate of the number daisies in each field
11. Count actual number of daisies in the field

Question 3

Quadrat:

Answer 3

set area used to measure number of (a) species in it

Question 4

Quadrant frame:

Answer 4

Piece of equipment of a defined size used to make an estimation of the number of organisms in a habitat

Question 5

Limitations of result:

Answer 5

• may have used too few quadrants / quadrants too small - sample size too small
• sample may not be representative of lawn - quadrants not placed randomly
• assumption is that the plant is distributed equally across the whole area
• lack of accuracy
• scientist bias due to not effective random placement of the quadrants
• to improve use grid and a random number generator to generate coordinates for the placement of the quadrant frames