Biodiversity

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).

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.

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

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.

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

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?

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)

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

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?

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)

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

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

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 = 0.203 D = 1 - (Σ(n/N)2) D = 1 - 0.203 = 0.797

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

Task Complete the questions

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 – 0.349 = 0.651

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

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).