Practical 11 - Investigation into biodiversity in a habitat

Question 1

What does biodiversity refer to?

Answer 1

The number of species (species richness)
The relative number of individuals within each species (species evenness)

Question 2

What does the method of estimating the biodiversity of a habitat depend upon?

Answer 2

The habitat

Question 3

What are the steps to assessing biodiversity of ground flora?

Answer 3

1. Using tape measures, set up a pair of axes at right angles to each other in the selected area
2. Generate random numbers to produce the figures for the x and y co-ordinates to identify the sampling position
3. Place the quadrat at the generated sampling position
4. Identify all species present and record the numbers of each present
5. Repeat for a total of 10 quadrats
6. Calculate the Simpson’s index for the area

Question 4

How many quadrats do we repeat both of these assessments for?

Answer 4

10

Question 5

Method of assessing the biodiversity of invertebrates

Answer 5

1. Use a fixed area sampler or mark an area with a quadrat
2. Place flat edges net held against the stream bottom downstream from the quadrat
3. Agitate the stream bed with a boot and “kick” for 2 minutes, covering the whole area evenly
4. Place the catch in a shallow white tray with 2cm depth of fresh water from the stream or river
5. Identify all species present and recorded the numbers of each present
6. Return animals about 1m upstream from where they were caught
7. Repeat for a total of 10 quadrats
8. Calculate the Simpson’s index for the stream

Question 6

What are the three main hazards, risks and control measures associated with field work?

Answer 6

Slippery surfaces - risk of strains and sprains - should wear appropriate footwear with grip
Biting and stinging insects and staining or thorny plants - risk of scratches and allergic reactions, which are controlled by wearing insect repellant and protective clothing
Different ecosystems have different hazards e.g - tide on a seashore, risk of being cut off, so the control would be to use tide tables an choose an appropriate time to work

Question 7

Where do we place the net for assessing biodiversity of infertebrates?

Answer 7

Against the stream bottom downstream from the quadrat

Question 8

Where do we release the animals after completing the identifying of species in a river?

Answer 8

About 1cm upstream from where they were caught