This is a unique type of vegetation which is listed as an endangered ecosystem in the Biodiversity Act 10 of 2004 because of the extent of irreversible loss already incurred.
It is associated with the Halfway House Granite Dome, a geological feature which extends over much of northern Johannesburg. Removing more than 300m2 of this vegetation (at once or in stages) without an environmental authorisation is an offence in terms of the National Environmental Management Act 107 of 1998.
The grass family is one of the most important families in the world, if not the most important. It forms the very basis of many complex ecosystems and all animals are therefore either directly or indirectly dependent of them for survival. Grasses are used as a food source as grazing for many different types of insects, frogs, reptiles and mammals. Many species use the grassland to build nests, forage for food, and use as shelter. Grasses provide shelter and shade protection from the sun, for a huge range of organisms and micro-organisms. Their roots protect the soil from wind and water erosion and this prevents soil from being degraded.
Grasses are able to withstand drought as they have thin-walled cells between the veins of their leaves. This feature allows them to expand their leaves under normal circumstances, and to curl their leaves up, to slow down the rate of evaporation from the leaves during a drought. Much of the grass plant is underground, and this allows grasses to survive drought, fire, heavy grazing and frost.
It is associated with the Halfway House Granite Dome, a geological feature which extends over much of northern Johannesburg. Removing more than 300m2 of this vegetation (at once or in stages) without an environmental authorisation is an offence in terms of the National Environmental Management Act 107 of 1998.
The grass family is one of the most important families in the world, if not the most important. It forms the very basis of many complex ecosystems and all animals are therefore either directly or indirectly dependent of them for survival. Grasses are used as a food source as grazing for many different types of insects, frogs, reptiles and mammals. Many species use the grassland to build nests, forage for food, and use as shelter. Grasses provide shelter and shade protection from the sun, for a huge range of organisms and micro-organisms. Their roots protect the soil from wind and water erosion and this prevents soil from being degraded.
Grasses are able to withstand drought as they have thin-walled cells between the veins of their leaves. This feature allows them to expand their leaves under normal circumstances, and to curl their leaves up, to slow down the rate of evaporation from the leaves during a drought. Much of the grass plant is underground, and this allows grasses to survive drought, fire, heavy grazing and frost.
Original & remaining extent of the Egoli Granite Grassland Ecosystem
It is interesting that grazers are dependent on grass, and that the grass is dependent on grazers. Grazers remove old material which stimulates new growth. They also provide fertilizer in the form of manure. Grazers such as cattle, trample the soil, breaking up crusted soil and this improves the germination of new grass seeds. Rodents such as African Spring Hare, hedgehogs and cane rats, use the grassland as a habitat. They eat grass seeds and the base of grass culms, which are rich in nutrients. Interestingly, the growth points of grasses are situated close to the ground level, out of reach of most larger grazing animals.
Birds such as weavers, finches and red-billed quelea use the grass to make their nests. Seed eating birds such as finches disperse the grass seeds.
The loss of grassland to agriculture and to urban development has affected many animal and insect species. This is of particular importance in Gauteng, where we have Egoli Granite Grasslands, which are not found anywhere else in the world.
Removal of indigenous grasses in order to plant lawns is strongly discouraged. Most lawn grass species are exotic or invasive and do not support biodiverse animal or insect life. Most lawn types such as kikuyu require a great deal of water to grow and are not tolerant to drought or to adverse conditions.
There are some indigenous grass species which can be planted in favour or kikuyu.
These include:
Birds such as weavers, finches and red-billed quelea use the grass to make their nests. Seed eating birds such as finches disperse the grass seeds.
The loss of grassland to agriculture and to urban development has affected many animal and insect species. This is of particular importance in Gauteng, where we have Egoli Granite Grasslands, which are not found anywhere else in the world.
Removal of indigenous grasses in order to plant lawns is strongly discouraged. Most lawn grass species are exotic or invasive and do not support biodiverse animal or insect life. Most lawn types such as kikuyu require a great deal of water to grow and are not tolerant to drought or to adverse conditions.
There are some indigenous grass species which can be planted in favour or kikuyu.
These include:
- Cynodon dactylon – Couch Grass
- Sactyloctenium australe – LM or Berea Grass
- Stenotaphrum Secundatum – Buffalo Grass
- Cynodon transvaalensis – Fine Couch grass
- Setaria Megaphylla – A broad-leaved bristle grass. This is a popular indigenous grass, particularly in shady areas.
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It is important to note that even grassland which might be considered degraded and with little value is still important as it will protect the soil from erosion and provide shelter to many organisms.
There are many species of grasses that occur throughout South Africa and each species has been given an ecological status which groups similar types of grass together based on their reaction to grazing.
There are 5 groups of grasses: Decreasers, Increaser I, Increaser II, Increaser III and Invaders.
Assessing the veld condition is done by doing a survey to determine the number and density of species in an area (called the species composition). There are several techniques used to analyse the data and all of them enable researchers to identify whether the grassland is healthy with a high biodiversity with a high ecological value, or degraded with few species and a low ecological value.
It is important to note that even grassland which might be considered degraded and with little value is still important as it will protect the soil from erosion and provide shelter to many organisms.
“Soil remains our most precious valuable agricultural resource. We should do everything in our power to conserve the production potential of soil for future generations. They will need it even more than we do”.
Frits van Oudtshoorn. Guide to Grasses of Southern Africa. Briza, 2020.
There are 5 groups of grasses: Decreasers, Increaser I, Increaser II, Increaser III and Invaders.
Assessing the veld condition is done by doing a survey to determine the number and density of species in an area (called the species composition). There are several techniques used to analyse the data and all of them enable researchers to identify whether the grassland is healthy with a high biodiversity with a high ecological value, or degraded with few species and a low ecological value.
It is important to note that even grassland which might be considered degraded and with little value is still important as it will protect the soil from erosion and provide shelter to many organisms.
“Soil remains our most precious valuable agricultural resource. We should do everything in our power to conserve the production potential of soil for future generations. They will need it even more than we do”.
Frits van Oudtshoorn. Guide to Grasses of Southern Africa. Briza, 2020.