Within a habitat it’s possible to measure the amount of biodiversity. Biodiversity refers to the varieties of life present and takes into consideration the total number of genes and species within a specific region. There are three main levels of biodiversity: ecosystem biodiversity, species diversity and intra-specific biodiversity.

Species diversity

Species diversity concentrates on the total number of species in a community. Humans have had a negative impact on species diversity in two main ways:

• intensive farming
• deforestation

Index of diversity

Simpson’s index of diversity is a way of measuring diversity. It’s used a lot in ecology within specific habitats. It looks not only at how many species are present but also the numbers of each species.

The calculation is:

d = N (N – 1)

? n (n – 1)

N = the total number of organisms of all species

n = the total number of organisms of each species

The larger the index, the more diverse the ecosystem.

——————————————————

Deforestation

Forests contain a wide variety of different species. However, the need for more land for agriculture, has led to massive areas of forest being destroyed. Tropical rainforests have been particularly hard hit. Deforestation has had a big impact on diversity. It’s led to the extinction of tree species, especially hardwoods and softwoods. It’s also affected the diversity of other species which use the trees for food or shelter. Many species that haven’t even been discovered yet might be lost. A forest is a community of species with their own complicated food webs: affecting one species will have a dramatic effect on many others and so on.