Index of Biodiversity Flashcards
An index of diversity is
a measurement that describes the relationship between the number of species present and how each species contributes to the total number of organisms that are present in that community
It is a much more informative measurement than species richness
For example, habitat A has 10 different plant species and habitat B has 7 different plant species
Habitat A would have a greater species richness score than habitat B
However, in habitat A there is only one individual of each plant species present (10 individuals present) while in habitat B there are over 20 individuals of each species present (over 140 individuals present)
Habitat B would have a greater index of diversity than habitat A
Once the abundance of different species in an area has been recorded the results can be used to calculate the species diversity or biodiversity for that area
Species diversity looks at
the number of different species in an area but also the evenness of abundance across the different species
The index of diversity formula
The formula is:
and what does it all mean
d = N(N-1)/ Σn(n-1)
n = total no. of organisms for a single species in the community
N = total no. of organisms in the community
Σ = sum of
The larger the number obtained, the higher the level of diversity
To calculate:
Step 1: ….
Step 2: …………
Step 3: ………..
Step 4: ………
Calculate N(N-1) to find value A
Calculate n(n-1) for each species
Add these numbers together to find value B
Divide value A by value B
PRACTICE THESE EVEN THOUGH GIVEN FORMULA
HIGHER THE NUMBER THE … BIODIVERSITY
HIGHER