Summary - Calculation of Species diversity

PAG 3.1 – The calculation of species diversity

AREA 1
Percentage cover (%)
Species 1 2 3 4 5 6 7 8 9 10 Mean
Grass 80 85 70 60 60 95 100 80 95 60 78.5
Clover 5 5 5 5 35 5 0 0 0 20 8
Dandelion 0 0 0 0 0 0 0 0 5 0 0.5
Daisy 0 5 0 5 0 0 0 0 0 20 3
Plantain 15 0 0 0 5 0 0 20 0 0 4
Yarrow 0 0 0 0 0 0 0 0 0 0 0
Chickwee 0 0 0 0 0 0 0 0 0 0 0
d
Cranes bill 0 5 25 30 0 0 0 0 0 0 6

D = 1 – ((n/N)2)
D = 1 – ((78.5/100)2+(8/100)2+(0.5/100)2+(3/100)2+(4/100)2+(0/100)2+(0/100)2+(6/100)2)
D = 0.37125

AREA 2
Percentage cover (%)
Species 1 2 3 4 5 6 7 8 9 10 Mean
Grass 50 10 5 5 60 70 65 60 80 80 48.5
Clover 5 0 5 15 10 0 10 0 0 10 5.5
Dandelion 10 0 0 0 5 0 0 0 0 0 1.5
Daisy 20 70 70 0 10 10 5 0 20 10 21.5
Plantain 5 0 15 60 10 0 0 20 0 0 11
Yarrow 5 15 0 10 0 20 20 20 0 0 9
Chickwee 5 0 0 0 0 0 0 0 0 0 0.5
d
Cranes bill 0 5 5 10 5 0 0 0 0 0 2.5

D = 1 – ((n/N)2)
D = 1 – ((48.5/100)2+(5.5/100)2+(1.5/100)2+(12.5/100)2+(11/100)2+(9/100)2+(0.5/100)2+(2.5/100)2)
D = 0.69445

Area 1 has a Simpson’s Index of Diversity of 0.37125. This is higher than Area 2’s value of
0.69445. This tells us that Area 2 has a higher biodiversity, when taking into account species
evenness and species richness. This means that Area 2 is more stable and able to withstand
change.