South Africa is one of only 17 countries worldwide considered megadiverse. It has more than 20,000 different plants, or about 10% of all the known species of plants on Earth, making it particularly rich in plant biodiversity. South Africa is the 6th most biodiverse country, after Brazil, Colombia, Indonesia, China, and Mexico. The most prevalent biome in South Africa is the grassland, particularly on the Highveld, where the plant cover is dominated by different grasses, low shrubs, and acacia trees, mainly camel-thorn and whitethorn. Vegetation becomes even more sparse towards the northwest due to low rainfall. There are several species of water-storing succulents like aloes and euphorbias in the very hot and dry Namaqualand area. The grass and thorn savannah turns slowly into a bush savannah towards the north-east of the country, with denser growth. There are significant numbers of baobab trees in this area, near the northern end of Kruger National Park.
The Fynbos Biome, which makes up the majority of the area and plant life in the Cape floristic region, one of the six floral kingdoms, is located in a small region of the Western Cape and contains more than 9,000 of those species, making it among the richest regions on earth in terms of floral biodiversity. The majority of the plants are evergreen hard-leaf plants with fine, needle-like leaves, such as the sclerophyllous plants. Another uniquely South African plant is the protea genus of flowering plants. There are around 130 different species of protea in South Africa.
While South Africa has a great wealth of flowering plants, it has few forests. Only 1% of South Africa is forest, almost exclusively in the humid coastal plain along the Indian Ocean in KwaZulu-Natal (see KwaZulu-Cape coastal forest mosaic). There are even smaller reserves of forests that are out of the reach of fire, known as montane forests (see Knysna-Amatole montane forests). Plantations of imported tree species are predominant, particularly the non-native eucalyptus and pine. South Africa has lost a large area of natural habitat in the last four decades, primarily due to overpopulation, sprawling development patterns and deforestation during the nineteenth century. South Africa is one of the worst affected countries in the world when it comes to invasion by alien species with many (e.g. Black Wattle, Port Jackson, Hakea, Lantana and Jacaranda) posing a significant threat to the native biodiversity and the already scarce water resources. The original temperate forest that met the first European settlers to South Africa was exploited ruthlessly until only small patches remained. Currently, South African hardwood trees like Real Yellowwood (Podocarpus latifolius), stinkwood (Ocotea bullata), and South African Black Ironwood (Olea laurifolia) are under government protection.
Numerous mammals are found in the bushveld habitats including lions, leopards, white rhinos, blue wildebeest, kudus, impalas, hyenas, hippopotamus and giraffes. A significant extent of the bushveld habitat exists in the north-east including Kruger National Park and the Mala Mala Reserve, as well as in the far north in the Waterberg Biosphere.
Climate change is expected to bring considerable warming and drying to much of this already semi-arid region, with greater frequency and intensity of extreme weather events such as heatwaves, flooding and drought. According to computer generated climate modelling produced by the South African National Biodiversity Institute parts of southern Africa will see an increase in temperature by about one degree Celsius along the coast to more than four degrees Celsius in the already hot hinterland such as the Northern Cape in late spring and summertime by 2050.
The Cape Floral Kingdom has been identified as one of the global biodiversity hotspots since it will be hit very hard by climate change and has such a great diversity of life. Drought, increased intensity and frequency of fire and climbing temperatures are expected to push many of these rare species towards extinction.
South Africa houses many endemic species, among them the critically endangered Riverine Rabbit (Bunolagus monticullaris) in the Karoo.