1. Biodiversity

2. Learning Objectives Success criteria Understand biodiversity
Learners should be able to demonstrate and apply their knowledge and understanding of:
(a) how biodiversity may be considered at different levels
To include habitat biodiversity (e.g. sand dunes, woodland, meadows, streams), species biodiversity (species richness and species evenness) and genetic biodiversity (e.g. different breeds within a species).
(c) how to measure species richness and species evenness in a habitat
(d) the use and interpretation of Simpson’s Index of Diversity (D) to calculate the biodiversity of a habitat
To include the formula: D = 1 – (Σ(n/N)2)
AND
the interpretation of both high and low values of Simpson’s Index of Diversity (D).

3. Biodiversity
The number and variety of living things to be found in the world/ecosystem/habitat. Biodiversity is essential in maintaining a balanced ecosystem for all organisms.

4. Measuring biodiversity
Plays an important role in conservation.
Environmental Impact Assessments (EIA) are undertaken to predict the positive and negative effects of a project on the biodiversity of an area.
Biodiversity can be measured at 3 levels:
Habitat biodiversity
Species biodiversity
Genetic biodiversity

5. Habitat Biodiversity
Number of different habitats in an area. Greater the habitat diversitythe greater the species diversity. UK – large number of habitat types e.g. Meadow, woodland, stream, sand dune - large habitat biodiversity. Antarctica – low number of habitat types e.g. ice sheet – low habitat biodiversity.

6. Species Biodiversity
Number of different species and the abundance of each species in an area.
Species richness
Number of species present in habitat
Species evenness
Measure of abundance of individuals in each species (ACFOR)
The greater the species richness and evenness the
higher the biodiversity

7. Genetic Biodiversity
Genetic variation between individuals of the same species (variation of alleles). The greater the genetic biodiversity within a species the more adaptable it is to changing environments. Suggest why greater genetic biodiversity increases a species chances of survival for the long term?

8. Simpson’s Index of Diversity
Measure biodiversity of a habitat taking into account species richness and species evenness
D = 1-(Σ(n/N)2)
n = number of individuals of a particular species (or percentage cover for plants)
N = total number of all individuals of all species (or percentage cover for plants)

9. Simpson’s Index of Diversity
Simpson’s index is always a value between 1 and 0.
Significance of high values of D (close to 1)
Diverse habitat
Small change in habitat may only affect one species
Habitat stable and can withstand change
Significance of low values of D (close to 0)
Habitat dominated by just a few species
Small change in habitat may effect one of the key species and damage whole habitat

10. Simpson’s Index of Diversity
Species n
n/N
(n/N)2 A 12 B 7 C 2 D 6 E 5 F 8
n=N=
(n/N)2 =
What is the species richness?

11. Simpson’s Index of Diversity
Species n
n/N
(n/N)2 A 12 B 7 C 2 D 6 E 5 F 8
n=N=
(n/N)2 =
Work out n (N=sum of all the species present)

12. Simpson’s Index of Diversity
Species n
n/N
(n/N)2 A 12 B 7 C 2 D 6 E 5 F 8
n=N=40
(n/N)2 =
Work out n (N=sum of all the species present)
Then work out n/N for all species

13. Simpson’s Index of Diversity
Species n
n/N
(n/N)2 A 12
0.300 B 7
0.175 C 2
0.050 D 6
0.150 E 5
0.125 F 8
0.200
n=N= 40
(n/N)2 =
Work out (n/N)2 for all species
Then add them all up for (n/N)2

14. Simpson’s Index of Diversity
Species n
n/N
(n/N)2 A 12
0.300
0.09 B 7
0.175
0.031 C 2
0.050
0.003 D 6
0.150
0.023 E 5
0.125
0.016 F 8
0.200
0.040
n=N= 40
(n/N)2 =
D = 1 - (Σ(n/N)2)
D = = 0.797

15. Biodiversity values Habitat feature Low biodiversity High biodiversity
Number of successful species
Relatively few
A large number
Nature of the environment
Stressful and/or extreme with relatively few ecological niches
Not stressful with more ecological niches
Adaptations of species to the habitat
Relatively few species in habitat, often with very specific adaptations for the environment
Many species in habitat, often with few specific adaptations to the environment
Types of food webs
Relatively simple
complex
Effect of a change to the environment on ecosystem as a whole
Major effects on the ecosystem
Often relatively small effect

16. Task
Complete the questions

17. 0.133
0.018
0.533
0.284
0.067
0.004
0.067
0.004
0.200
0.040
Σ(n/N)2 = 0.349
N = 15
D = 1 - (Σ(n/N)2)
D = 1 – = 0.651

18. number of individuals of each species in each habitat
Species richness - number of different species present
number of individuals of each species in each habitat
species
barley field
wheat field
under hedge
n/N
(n/N)2 a 32 4
0.163
0.027 b 78 1
0.398
0.158 c
126 2 d 5 12 e 8 f 9 g 25 3 h 10 i j k 86 56
0.439
0.193 l 7
species richness 6
total number of insects (N)
196
226 52
Simpson’s Index of Diversity (D)
0.62
0.61
0.86
0.378

19. Learning Objectives Success criteria Understand biodiversity
Learners should be able to demonstrate and apply their knowledge and understanding of:
(a) how biodiversity may be considered at different levels
To include habitat biodiversity (e.g. sand dunes, woodland, meadows, streams), species biodiversity (species richness and species evenness) and genetic biodiversity (e.g. different breeds within a species).
(c) how to measure species richness and species evenness in a habitat
(d) the use and interpretation of Simpson’s Index of Diversity (D) to calculate the biodiversity of a habitat
To include the formula: D = 1 – (Σ(n/N)2)
AND
the interpretation of both high and low values of Simpson’s Index of Diversity (D).