Paper 5

Question 1

Describe a random (unbiased) method which students could have used to collect the data needed to calculate the biodiversity of the plant species (using Simpson’s Index of Diversity) in an ungrazed area & grazed area.

Answer 1

any 8 from:
1 ref. to sampling in both areas / grazed and ungrazed ;
2 any idea of marking out the area to be sampled ;
3 use a method of generating random numbers (to use coordinates) ;
4 use a (frame or point) quadrat (for individual samples) ;
5 place (quadrat AW) at coordinates ;
6 ref. to method of identifying or distinguishing different
species / types / sorts of plant ;
7 ref. to counting/recording of:
number of individuals or the population of/ each
type/ sort/ species present (in quadrat/ plot)
or
the total number of all the plants present (in quadrat/ plot) ;
8 same size quadrat/ same quadrat AW ;
9 same size plot in each area ;
10 same number of different quadrats/ samples per plot ;
11 replicate the procedure with a different plot in a given area ;
12 sample at different times of year/ seasons ;
13 safety
any 1 from:
* ref. to injury / getting lost and staying with group ;
* allergy to plants and wearing gloves /protective clothing ;
* allergy to pollen/ hay fever and wearing mask or taking
medication ;
* ref. to uneven ground/ hazardous plants or animals or
environment and wearing suitable shoes/protective
clothing ;

Question 2

State what information is gained by calculating the confidence intervals with standard error.

Answer 2

• shows reliability of the mean
• a mean is more reliable than another if its standard error is smaller
• the difference between means is significant if the confidence intervals for standard error do not overlap with one another

Question 3

Why is the Spearman’s rank correlation test used in certain studies?

Answer 3

• data is, non-linear / skewed
• data not normally distributed
• data is discontinuous / discrete
• scatter graph may show that there is a relationship
• data samples are independent
• ref. to random selection

Question 4

Describe an investigation to find out how the distribution & abundance of the different species of algae varies on a rocky shore with no rock pools from the LWM to the HWM.

How to carry out a belt transect?

Answer 4

Sampling process:
- Place a rope from one point to another / from LWM to HWM
- Sample at regular intervals along the transect
- Use a quadrat
- Same size of quadrat

Measuring process:
- Method of identifying (species of algae)
- Take care not to miss small species
- Count number of different species (of algae) (in each quadrat)
- Repeat belt transect at 2 other positions along the shore & calculate means
- Named suitable hazard AND risk AND precaution
- AVP