Status of biodiversity

Biodiversity refers to the degree of variety among living organisms that occur at a place – the more diversity the healthier the ecosystems. Three common ways to measure diversity are: alpha diversity, which measures the number of different kinds of creatures in an area (species richness); beta diversity, which measures species diversity between ecosystems (habitat patchiness); and gamma diversity, which measures how many creatures in an area also occur elsewhere (affinity).

South Africa’s grasslands have a high alpha diversity, moderate gamma diversity and high rates of beta diversity where topographical and environmental gradients are steep.

Of the 80 vegetation types in the biome, 2 are listed as critically endangered, 18 are endangered and 27 are classed as vulnerable.
83% of river ecosystems are ranked as threatened, with 48% critically endangered.
The biome contains South Africa’s national bird, the blue crane, the critically endangered wattled crane and Rudd’s lark.
Of the 195 reptile species endemic to South Africa, 22% are found in the biome.
A third of the 107 threatened South African butterfly species occur in the grasslands.
Wetlands are particularly important in the grasslands.