Not just a bunch of grass... the amazing biodiversity of the Woodbush Granite Grasslands derives mainly from its wildlfowers, veld flowers in South African parlance. Isolated trees do occur, such as Cabbage Trees (Cussonia spp.), Acacia spp. especially A. sieberiana, and the Common Spike-Thorn Gymnosporia buxifolia. Several indigenous forest patches also dot the grasslands, but it is the wildflowers which steal the show. For more general info on South African Grasslands: http://www.eiatoolkit.ewt.org.za/documents/biodiversity/grassl~1.pdf
According to taxonomist Pieter Winter, around 630 plant species have been recorded from the Haenertsburg Grasslands, an area of roughly 240 ha. This compares with approximately 1010 species found in the Sabie area (130 000 ha). Winters Analysis of the Flora of the Haenertsburg Commonage (Haenertsburg Townlands) is the key reference for the botanical aspects of these grasslands.
Of the roughly 630 plants species, only 53 grasses have been recorded. The bulk of the biodiversity is made up of forbs; or wildflowers. The family Asteraceae is well represented, with 94 species. The most common genus is Helichrysum (Everlastings) with 21 species, while orchids, Gladioli, Watsonias, Aloes and many more are also found.
A special place is just below the Haenertsburg Primary School, between the school and the Roads Camp. A series of rocky outcrops here harbours many Blue Squills (Merwilla plumbea) as well as Aloes and the Bushman Poison Bulb, Boophone disticha. Blue Squills prefer rocky places but are also found in sandy soil on the Ebenezer Dam Peninsula, which is also a protected area.
Many of these grassland plants are used medicinally, which is part of the reason that these grasslands are of economic value. A number of traditional healers collect plants from the grassland, and are in contact with FROHG so that we gain some idea of the species and numbers harvested.
Why is the Grassland so rich in species?
One answer is that this area was never glaciated (unlike much of the northern hemisphere). These grasslands have been dated back to about 18 000 years ago, using various technologies such as fossil pollen studies. If an ecosystem is around that long in a relatively undisturbed state, it has a chance to evolve many unique species which are found nowehere else. By contrast, if an ecosystem experiences repeated glaciation events, the whole ecosystem has to start from scratch every time and a comparatively species-poor ecosystem results. The Great Lakes region of the USA is an example of this. South Africa has far more plant species than the entire USA, which is a much larger area.
The Louis Changuion Hiking Trail meanders through four or five forest patches, which are home to large trees such as Yellowwoods, Cabbage Trees, White Stinkwoods, Cape Chestnuts and Fig Trees. Lianas (vines) span the canopy, which is home to many birds including the Knysna Lourie. Vervet monkeys, duikers and bushbuck also inhabit the forests.
Blue Swallows and Methuens Dwarf Gecko are just two red data species recorded from these grasslands and vicinity. Eastwoods Long-tailed Seps, a snake-like lizard not seen for 80-odd years, is believed by some scientists to still live here. The Wolkberg Zulu butterfly, a critically endangered insect recorded only from a tiny grassland patch near Haenertsburg, is another species reliant on these grasslands. The Bolas Spider, which hunts moths, gaucho-style, with a silk thread, was found here a few years ago. It was previously known only from KZN. Secretary birds were seen in the Haenertsburg grasslands during 2007, for the first time in many years. Unfortunately one flew into a powerline and died. FROHG has now asked ESKOM to install flappers on the powerlines.
Ironically the planting of natural grasslands to pine and eucalyptus in the early 1900’s was regarded as a forward thinking conservation measure, providing an alternative to indigenous forest timber needed to construct wagons, carts, buildings, furniture and mine supports particularly on the Witwatersrand. The destruction of grasslands led to the demise of associated flora and fauna. Some flora like Kniphofia crassifolia and the small lizard Eastwood's long tailed seps(Tetradactylus eastwoodii), are believed to be extinct. The fate of the critically endangered Hirundo atrocaerulea (Blue swallow), Acontophiops lineatus (Woodbush legless skink) and Afroedura pondolia mulitiporis (Methuen’s dwarf gecko) remain precarious.
Threatened species, as a conservation status, are animal and plant species which are at risk of being extinct. The best-known worldwide conservation status listing and ranking system, is the IUCN Red List. Other more specialised lists and systems exist, such as The Nature Conservancy's conservation status ranking system and CITES. By monitoring these species, the ecology of an area is assessed.
Threatened species are animal and plant species which are at risk of being extinct. Threatened species include all species which are vulnerable, endangered or critically endangered. The conservation status of a species is an indicator of the likelihood of that species continuing to survive, either in the present day or the future. Many factors are taken into account when assessing the conservation status of a species, not simply the number remaining, but the overall increase or decrease in the population over time, breeding success rates, known threats, and so on.
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A plant or animal that is confined to a certain area is called endemic. Some organisms are endemic to the African continent and are therefore, not found anywhere else in the world. There are many organisms endemic to small regions and these plants and animals are extremely vulnerable as any change to their habitat could cause their extinction, as there would be no other populations in other areas to continue the race.
The Cape Parrot is the only parrot endemic to South Africa. Two disjunct populations, with less than 650 individuals, exist in the country and in the Yellowwood forests of the Eastern Cape. They are found in indigenous forest patches of the Eastern Cape, KZN and Limpopo Provinces. There are no Cape Parrots in Mpumalanga.
Golden moles, as a whole, are endemic to the Southern African sub-region. Gunning´s Golden Moles are known only from the Woodbush Forest and the Agatha Forest reserve. The Golden Mole is a montane forest and grassland species. It feeds on ground-dwelling insects, and those found on the surface. Blind, but with excellent burrowing skills, it makes runs of tunnels just below the surface of the soil, which can be seen as cracks on the surface. It is threatened by alien forestry, human settlements and frequent fires.
Islands of montane evergreen high forest and adjacent montane grasslands are isolated by plantations, roads and other developments. These natural areas support threatened species including three snake species, the African Rock Python, the Swazi Rock Snake and the Striped Harlequin Snake.
This gecko is large for a dwarf gecko. It has an olive-grey colouring. It is endemic to the Woodbush Forest area and Haenertsburg Common. The few small populations are threatened by alien forestry plantations and frequent fires. They are usually found basking on the boles of large trees or on rocky outcrops
This type of grassland has a high conservation value as most has been lost to development. Most of the threatened plants of the area occur in grasslands and include orchids, succulents and bulbs. Out of every six plants in a grassland, only one is a grass. Grassland plants are often overlooked, particularly in winter when they die back to survive the frost and fires. Large underground tubers, bulbs and rootstocks are typical of grassland plants. These are often highly sought after in the medicinal plant trade and may occur nowhere else.
The Northern Forest Rain Frog is endemic to the Limpopo Province, occuring on the Blouberg, Soutpansberg, Wolkberg and Drakensberg ranges. It is restricted to fragments of natural habitat that have not been transformed into plantations or human settlements. Roads fragment the remaining suitable habitat, causing large-scale die-offs during the breeding season, when the frogs are active. Frogs are susceptible to global warming and pollution due to their thin, bloodrich skins. Adult Northern Rain Frogs hibernate underground or underneath rocks and logs during winter. They emerge with the spring rains and have a distinct long whistle as a mating call.
The Southern Ground Hornbill is a long-lived bird, and is the largest co-operative breeding bird in the world (and as such, is of great interest to science). They live in groups of 2 to 12 individuals that occupy and vigorously defend large territories of up to 100 square kilometres. Groups can either consist of a single breeding pair or a large group with a dominant breeding pair and helpers of various ages.
A critically endangered, localised species occuring in colonies on grassy slopes next to a forest in the Haenertsburg area. The butterflies emerge from late December to early January.
Another gecko endemic to the area, which has only been found between the Woodbush Forest and Wolkberg Mountain Range. A population is present at Serala in the Wolkberg. The geckos live singly in crevices and under exfoliating rock in open woodland and montane forest. They are threatened by afforestation and forestry activities.