This vast area is centred on the towns of Volksrust and Wakkerstroom. The proposed Biosphere Reserve comprises some 800 private farms, several municipalities and conservancies and a considerable amount of state-owned land. The site comprises gentle rolling hills on the South African plateau (1,700–1,800 m) that are broken regularly by parts of the Mpumalanga Drakensberg escarpment, small ranges such as the Gemsbokberg (2,095 m), Versamelberg (2,139 m) and Balelesberg (2,055 m), and higher peaks around Wakkerstroom, such as Ntshele (2,291 m), Ossewakop (2,170 m), Kanonkop (2,112 m) and KwaMandlangampisi (2,266 m). The area covers several catchments and holds many perennial rivers and wetlands. The following wetlands are of international importance and deserve the highest possible conservation attention. Wakkerstroom vlei (27°22’S 30°07’E), which lies on the border of the town, is a marsh, predominantly a mosaic of Carex and Leersia stands. Seekoeivlei (27°35’S 29°35’E), a Ramsar Site, is situated in the north-eastern Free State, 500 m from the town of Memel. It consists of a flood-plain holding numerous seasonally flooded oxbow lakes, which are drained by the Klip river, a tributary of the Vaal. Heyshope Dam (27°00’S 30°30’E), a proposed Ramsar Site, is a large impoundment in the Assegaai river catchment of south-eastern Mpumalanga. The privately owned Vanger Natural Heritage Site (27°52’S 29°40’E) lies about 30 km south-east of Memel. Blood river vlei (27°47’S 30°35’E) is situated 20 km south-west of Vryheid.Several other small important wetlands are scattered throughout the IBA. The terrestrial vegetation is dominated by some of the finest rolling grasslands remaining in South Africa. The most dominant grassland-type is moist sandy highveld grassland. The eastern boundary of the proposed Biosphere Reserve holds north-eastern mountain grassland. Small patches of moist clay highveld grassland grow on the black vertic clays that are scattered throughout the area, mostly in and around the Wielspruit catchment. Rocky slopes, gullies and ravines favour the development of thickets dominated by Leucosidea, which forms dense monospecific stands in places. Particularly in the Pongola Bush Nature Reserve, Ncundu Bush Nature Reserve and several privately owned areas along the escarpment, the thicket has developed into Afromontane forest, holding trees of Podocarpus, Rhus, Trichocladus, Curtisia, Halleria and Kiggelaria.
See Box and Tables 2 and 3 for key species. This area holds a significant proportion of South Africa’s small known population of the globally endangered Sarothrura ayresi. Three wetlands within the proposed Biosphere Reserve are known or thought regularly to hold Sarothrura ayresi in seasons of suitable rainfall. Crex crex is also regular at some of the reserve’s wetlands. Seekoeivlei supports large numbers of a rich diversity of resident and migratory waterbirds. The site also holds all three of South Africa’s crane species, including important numbers of Grus carunculatus. Heyshope Dam is known to hold extremely large numbers of at least 52 species of resident, migratory and nomadic waterbirds. Small portions of the dam, which are regularly counted, hold up to 45,000 waterbirds, suggesting that the entire system may hold an extrapolated total of some 100,000 individuals.Of the terrestrial birds, most of South Africa’s threatened and endemic grassland species have their core populations centred on the proposed Biosphere Reserve. An estimated 85% of the global population of Heteromirafra ruddi is thought to occur within the proposed reserve. Spizocorys fringillaris, which also occurs within this site, is highly localized within moist clay highveld grassland on black clays or dolerite soils. Anthus chloris favours mid-altitude, well-developed lightly grazed or ungrazed grassland. The largest breeding colonies of Geronticus calvus in the world occur within the proposed Biosphere Reserve. Large numbers also forage and roost throughout the area. Grus paradisea, Neotis denhami and Eupodotis senegalensis are widespread at low densities. Glareola nordmanni occasionally occurs in very large numbers during the austral summer. On exposed outcrops and rocky slopes at higher altitudes, Anthus crenatus, Geocolaptes olivaceus, Saxicola bifasciata and Monticola explorator are common. Promerops gurneyi is found around proteoid woodland on the escarpment, and Ciconia nigra breeds on steep cliffs. Pongola Bush Nature Reserve and other forest patches hold Cossypha dichroa, Serinus scotops, Lioptilus nigricapillus and Zoothera gurneyi.
Non-bird biodiversity: North-eastern mountain grassland holds 78 endemic and near-endemic plant species on the Black Reef quartzites, and there are a further 31 endemics on dry dolomite. Most of these endemics are present within the site. Many endemic animals also occur here.
Pressure/threats to key biodiversity
The proposed Grassland Biosphere Reserve is undoubtedly one of the most important biodiversity areas in Africa. It consists primarily of private and state-owned land; a few small protected areas are found within its boundaries, including Wakkerstroom and Seekoeivlei Nature Reserves. More than 20,000 ha of private land have been registered as Natural Heritage Sites. Despite ‘proposed Biosphere Reserve’ status, this area is severely threatened and it faces some monumental conservation problems. Foremost amongst these are grassland afforestation, wetland degradation, accidental and targeted poisoning of cranes and increased acid rain from local power station sulphur emissions.Commercial afforestation is the most looming threat. Although virtually none of this area is currently afforested, over 100,000 ha has been designated as prime plantation area. Plantations consume vital grassland habitat supporting many globally and nationally threatened taxa. Furthermore, the impacts of grassland fragmentation and other landscape-level changes are unclear, but could be catastrophic. Afforestation is also known to affect wetlands; the planting of non-native trees with poor water-utilization efficiency results in reduced run-off around wetlands.Wetlands within the proposed Biosphere Reserve face several other threats. Dam construction floods these ecosystems, turning them into sterile stretches of open water, and ecosystem processes are also disrupted downstream. Drainage by canals detrimentally affects wetlands. Overgrazing and burning of marshy areas in winter leads to temporary damage, with accelerated run-off, soil erosion and the formation of dongas. Several threatened species are affected dramatically by this wetland degradation, including Sarothrura ayresi.Although the proposed Biosphere Reserve and its biota face many threats, establishing state-owned nature reserves would not necessarily enhance the conservation status of grassland birds. Some species, Spizocorys fringillaris for example, favour closely cropped grassland, kept short by frequent fires and grazing. Today, such habitat is found on sheep farms where grazing is frequent. Providing incentives for land-owners to manage the grassland on their farms for particular species or communities of birds can be a very effective conservation strategy. Appropriate conservation action within this region would be to stimulate the creation of conservancies and cooperation between groups of land-owners (farmers), conservationists and scientists who share a common vision for the conservation and management of the proposed Biosphere Reserve’s biota. Detailed research into the ecological requirements of the threatened endemics is a high priority. Without this information, it will be impossible to implement effective management and conservation strategies.
BirdLife International (2023) Important Bird Areas factsheet: Grasslands. Downloaded from
http://www.birdlife.org on 31/03/2023.