How to Calculate a Biodiversity Index
The question of how many different species exist in a particular environment is central to the understanding of why it is important to promote and preserve species diversity. A uniform population of a single species of plants adapted to a particular environment is more at risk if environmental changes occur. A more diverse population consisting of many species of plants has a better chance of including individuals that might be able to adapt to changes in the environment.
Scientists use a formula called the biodiversity index to describe the amount of species diversity in a given area. A simple biodiversity index is calculated as follows:
|= biodiversity index|
For example, a 4 X 4 meter square area in a carrot patch has 300 carrot plants, all the same species. It has a very low biodiversity index of 1/300, or 0.003.
A 4 X 4 meter square area in the forest has 1 pine tree, 1 fern, 1 conifer tree, 1 moss, and 1 lichen, for a total of 5 different species and 5 individuals. The biodiversity index here is high, 5/5 = 1.
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This brief online article show students how to use a formula called the biodiversity index to describe the amount of species diversity in a given area.
- The article starts with an explanation of why an environment with a single species of adapted plants is more at risk.
- Two sample calculations are given along with the formula, illustrating how the formula can be applied to a carrot patch or a forest area.
Supplement a study of biodiversity with an activity drawn from this look at the biodiversity index.
- Ask students which area they think is at greater risk during environmental changes“an area with a single plant species or one with several dozen.
- Send students to this online article, or print copies of it for them to read.
- Have students identify several different nearby environments and calculate the biodiversity index for each one.
SubtopicTools and Methods