Measuring biodiversity

QCAA Biology, Unit 3

- determine diversity of species using measures such as species richness, evenness (relative species abundance), percentage cover, percentage frequency and Simpson's diversity index
- Guidance: Diversity indices and measurements should be supported through fieldwork and based on classification. Measures of biodiversity, i.e. species richness (S) and Simpson's diversity index (D) should be used where applicable
- Guidance: The formula used to quantify biodiversity of a habitat is Simpson's diversity index (SDI), shown as:
𝑆𝐷𝐼=1−(Σ𝑛(𝑛−1)/𝑁(𝑁−1) )
𝑊ℎ𝑒𝑟𝑒:
𝑁=𝑡𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑜𝑟𝑔𝑎𝑛𝑖𝑠𝑚𝑠 𝑜𝑓 𝑎𝑙𝑙 𝑠𝑝𝑒𝑐𝑖𝑒𝑠
𝑛=𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑜𝑟𝑔𝑎𝑛𝑖𝑠𝑚𝑠 𝑜𝑓 𝑜𝑛𝑒 𝑠𝑝𝑒𝑐𝑖𝑒𝑠