|At a Glance|
|Conservation Status||Endangered in eThekwini|
The Grassland Biome is found in the Highveld region, parts of the Eastern Cape, the Drakensberg, Northern KZN, the KZN Midlands with the eThekwini Outer West being the eastern limit within KZN.
The Grassland Biome is the 2nd largest of South Africa's 8 biomes, covering almost one third of the land surface, across 7 of the provinces.
The biodiversity of the Grassland Biome is extremely rich and is second only to the Fynbos Biome.
Grasslands typically have summer rainfall of 400 mm to 2000 mm. Winters are cold, and frost can occur.
Soil and Geography
Grassland is generally dominated by a single layer of grasses, of which there are two main categories: sweetveld and sourveld.
Vegetation is mainly various grass species with some trees on the hills and along river beds. The first shoots of grass and flowers appear shortly after fires have occurred. Thereafter the dominant grass species are Aristida junciformis subsp. galpinii, Elionurus muticus and Eragrostis plana.
Traditionally grasslands supported many grass-eating herbivores such as Zebra, Wildebeest, Eland and various antelope species. Raptors are also commonly found hunting in grasslands as they feed no the many rodents that flourish. Grasslands are also home to many insects such as ants, crickets and butterflies that feed on the various plant species.
Role of Fire
Naturally occurring fire is an essential component of grassland health as many plant species rely on fire as part of their regeneration process.
In developed areas controlled burning has become an important management process to maintain the health of grasslands. Current knowledge suggest burning cycles of 2 to 3 years but this is dependent on many factors such as rainfall.
The conditions that prevail in grasslands make them highly suitable for human habitation. Critically this has resulted in KwaZulu-Natal Sandstone Grassland now being classified as Endangered as a result of industrial and housing development.
In the eThekwini area, between 75 - 80% of the grasslands have been irreversibly modified with only 0,2% under formal protection.
Please do not pick the flowers, you are removing a seed source and a food source.
Krantzkloof Nature Reserve
The grasslands in Krantzkloof categorised as KwaZulu-Natal Sandstone Sourveld. This biome is characterized by a generally high rainfall during a hot summer (above 625mm per year), followed by a cold, dry winter. Over many years this high rainfall has weathered the sandstone and has leached the sandy soil of its nutrients, resulting in acidic soil, which is low in nutrients. In order to survive, the grasses have adapted by withdrawing the nutrients from their leaves during the cold winters and storing them in their roots. These reserves are then used to start regrowth in spring. This renders sourveld grasses low in nutritional value and high in fibre, making them unpalatable, particularly during winter.
In Krantzkloof Nature Reserve the Plains Zebra graze on the seed-heads of the Ngongoni Bristle Grass (Aristida junciformis).
The small patch of KZN Sandstone Sourveld Grassland in the park has been maintained thanks to the foresight of the late Greg Bosch who worked for the then Outer West Council and who insisted on preserving this particular patch of grassland. Although small in size it still provides a wealth of biodiversity and helps to mitigate the lawned and developed areas of the park.
Grassland biomes are found on each continent except Antarctica
The Grassland biome is also considered to face the greatest risk of significant change due to climate change.
The other biomes in South Africa are: Savanna (largest biome), Forests, Succulent Karoo, Nama Karoo, Fynbos, Thicket and Desert.