Conservation Value of the Egoli Granite Grassland, an Endemic Grass- Land in Gauteng, South Africa

Conservation value of the Egoli Granite Grassland, an endemic grassland in Gauteng, South Africa

G.J. Bredenkamp, L.R. Brown and M.F. Pfab

Bredenkamp, G.J., L.R. Brown and M.F. Pfab. 2006. Conservation value of the Egoli Granite Grassland, an endemic grassland in Gauteng, South Africa. Koedoe 49(2): 59–66. Pretoria. ISSN 0075-6458. Gauteng is the most densely populated province in South Africa. Its remaining natural areas are constantly under threat from urban development and the associated impacts. Presently, the natural areas of Gauteng support a large diversity of ecosystems. One such ecosystem is the Egoli Granite Grassland, endemic to the province, poorly conserved and therefore highly threatened. This paper describes the original Egoli Granite Grassland and the anthropogenic Hyparrhenia hirta dominated grassland that has replaced it in many of the remnant areas. Human impacts on this sensitive ecosystem have resulted in an altered species composition, loss of many species, and a change from a species-rich grassland with high conservation value to a species-poor grassland with low conservation value. The conservation of the last remaining relicts of original Egoli Granite Grassland is essential. Keywords: Egoli Granite Grassland; conservation value; Hyparrhenia hirta, Gauteng.

G.J. Bredenkamp, African Vegetation and Plant Diversity Research Centre, University of Pretoria; L.R. Brown, Applied Behavioural Ecology and Ecosystem Research Unit, University of South Africa; M.F. Pfab, Bioregional Planning, Gauteng Department of Agriculture, Conservation and Environment, Johannesburg, 2001 South Africa.

Introduction in the transition zone between the Grassland and Savanna biomes. The Egoli Granite Grassland is a type of grassland and a mapping unit (Gm10) clas- From a conservation planning or urban devel- sified under the Mesic Highveld Grassland opment viewpoint, the range of structural Bioregion according to the new Vegetation and floristic variation is considered too large Map of South Africa, Lesotho and Swazi- to define Bankenveld as a single unit, even land (Mucina et al. 2005). This grassland on the reconnaissance level of vegetation was mapped as Bankenveld (veld type 61) investigation. Bredenkamp & Brown (2003) by Acocks (1988), and Rocky Highveld recognised 16 major vegetation types within Grassland (Vegetation Type 34) by Breden- Bankenveld. The Egoli Granite Grassland kamp & Van Rooyen (1996). Acocks (1988) is considered as mainly belonging to the describes the Bankenveld as a False Grass- Hyparrhenia hirta Anthropogenic Grassland veld Type. The climax vegetation of this (Bredenkamp & Brown 2003). veld type should be, according to Acocks, an Egoli Granite Grassland is restricted to the open savanna, that is a bushveld vegetation, Gauteng Province of South Africa and is but it has been changed to, and maintained located north of the Roodepoort / Krugers- as grassveld by regular veld fires. How- dorp ridge complex and stretches over a ever, Bredenkamp & Brown (2003) consider distance of approximately 35 km to Centu- Bankenveld vegetation as a mosaic of grass- rion in the north. This grassland stretches land and woodland communities controlled over a distance of approximately 50 km in a by (micro-)climatic conditions that exist in westerly direction from the R21 highway in the topographically heterogeneous landscape the east. The 28º longitude and 26º latitudi-

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PTA

JHB

10 0 10 20 Kilometers

60 0 60 120 Km Fig. 2. Dark gray represents remnant areas of poten- Fig. 1. Locality map of the Egoli Granite Grassland. tially original Egoli Granite Grassland; perennial Grey areas indicate urbanisation rivers shown.

nal lines cross in the centre of this grassland ing 3 ha in Glen Austin Bird Sanctuary, 3 ha (Fig. 1). in Melville Koppies Nature Reserve, 9 ha in Ruimsig Nature Reserve, and 11 ha in the Due to high demand for developable land in Walter Sisulu Botanical Gardens (Fig. 2). Gauteng, and especially the Johannesburg / The current protection status of Egoli Granite Pretoria corridor, the Egoli Granite Grassland Grassland is therefore completely inadequate, is under extreme pressure. Large areas are with only 0.1 % of the national target actually already developed for residential, industrial achieved. In order to meet South Africa’s and commercial purposes. This has led to the international obligations, it is imperative that destruction of vast tracts of this grassland. the Gauteng provincial government put in At least 61 % of Egoli Granite Grassland has place measures to improve the conservation been permanently transformed: 27 % by urban status of Egoli Granite Grassland. development (Fig. 2); 17 % by smallholdings; 12 % by agriculture (cultivated lands); and Any viable remnant patch of original Egoli 5 % by other impacts such as exotic plan- Granite Grassland must therefore be pro- tations, mining and planted pastures. An tected from transforming land uses. In order estimated additional 17 % of Egoli Granite to assess whether a valuable remnant patch Grassland is degraded due to overgrazing and will be affected by a proposed develop- the influence of edge effects associated with ment, environmental consultants involved in a highly fragmented landscape (Fahrig 2003). vegetation impact assessments are required Other effects, such as trampling, increased by the Gauteng Department of Agriculture, pollutants and the infestation of weeds and Conservation and Environment (GDACE) to alien species also contribute to degradation assess the presence and condition of Egoli of this grassland. It is therefore highly likely Granite Grassland on any site proposed for that the national target for conservation of development. this grassland type, i.e., 25 % of the total As this grassland was only recently defined extent, will never be realised. with the development of the new Vegetation Egoli Granite Grassland is extremely poorly Map of South Africa, Lesotho and Swaziland conserved, with only 0.02 % (26 ha) of the (Mucina et al. 2005), very little information vegetation type currently protected, includ- on its floristic composition, condition, the

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bredenkamp.indd 60 2006/10/15 10:51:02 PM extent of the grassland, and the manage- Vegetation ment thereof exists, causing some confusion among nature conservationists, environmen- Current vegetation tal consultants and local authorities. The aim of this paper is therefore to provide an eco- This tall grassland occurs over vast areas, logical overview of this grassland. usually on shallow, leached soils on the Johannesburg Granite Dome. Disturbed grassland or other disturbed areas such as Physical Environment road reserves or old fields, not cultivated for some years, are also usually Hyparrhenia This area is generally characterised by rocky species-dominated and low in species rich- undulating plains representing crests, slopes ness. Although some of these tall grasslands and valley bottoms with shallow, nutrient- appear to be quite natural, they are mostly poor soils. Shallow drainage lines and vlei- associated with an anthropogenic influence like wetland areas occur in the valley bot- from recent or even iron-age times. toms. Rockiness of the soil surface is a fur- These grasslands are characterised by the ther common characteristic shared by most tall-growing dominant grass Hyparrhenia Bankenveld areas. hirta and the invader dwarf shrub Seriphium Mean monthly temperature in the study area plumosum (=Stoebe vulgaris), indicating its low successional status or degraded condi- is 16.8 ºC with a mean maximum of 22.6 ºC tion. and a mean minimum of 10.8 ºC. The mean winter temperature is 13.8 ºC and mean sum- Dense Hyparrhenia species-dominated grass- mer temperature, 25.6 ºC (Weather Bureau land mostly has low species richness, with 2000; Grobler et al. 2002). Mean annual rain- only a few other species able to establish or fall in Gauteng is 670 mm (Gauteng 1997). survive in the shade of the dense sward of tall grass. Most of these species are relict Old granitic and gneissic rocks at least 2 400 pioneers or early seral species. The most million years old (Kerfoot 1987) are exposed prominent species include the grasses Cyno- in the Egoli Granite Grassland area. The Half- don dactylon, Eragrostis chloromelas, E. way House Granites (Fig. 3) of the Johannes- racemosa, E. curvula and Aristida congesta. burg Dome are intensively weathered with Forbs are rarely encountered, though a few deep drainage lines resulting in a gently individuals of species such as Anthospermum rolling topography, with shallow, coarse, hispidulum, Pseudognaphalium luteo-album, nutrient-poor, well-drained soils. The granite Conyza albida, C. podocephala, Crabbea areas are mostly covered by grassland vege- angustifolia, Helichrysum nudifolium and tation though patches of woodland vegetation H. rugulosum are often present. The woody are found at sheltered sites on hillslopes and layer, which has a very low cover, consists of rocky outcrops within this veld type (Grobler small clumps of indigenous trees and shrubs widely scattered within this grassland. The 2000; Grobler et al. 2002, 2006). scanty woody species include the trees Rhus The Bb land type predominates over the pyroides and Ziziphus mucronata, together entire region (Land Type Survey Staff 1984, with the scandent shrub Ziziphus zeyheri- 1985, 1987) (Fig. 3). The residual granitic ana. Declared alien invasive species such as soils are very shallow and poorly drained. Melia azedarach, Eucalyptus species, Pinus The A horizon is often sandy and light in species and planted ornamentals are often colour with little organic matter and with an present. increase in clay content with depth. The soils Typical species found in anthropogenic are invariably acid and very rich in silica Hyparrhenia hirta-dominated Egoli Granite (Kerfoot 1987). Grassland are indicated below:

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bredenkamp.indd 61 2006/10/15 10:51:02 PM - Trees and Shrubs Nidorella hottentotica DC. Acacia caffra (Thunb.) Willd. Pseudognaphalium luteo-album (L.) Hilliard & *Eucalyptus species B.L.Burtt Gymnosporia buxifolia L. Szysyal Schkuhria pinnata (Lam.) Cabrera *Melia azedarach L. Seriphium plumosum L. Olea europaea L. ssp. africana (Mill.) P.S.Green Tagetes minuta L. *Pinus species Verbena bonariensis L. Rhus lancea L.f. Verbena brasiliensis Vell. Rhus leptodictya Diels Vernonia oligocephala (DC.) Sch.Bip. ex Walp. Rhus pyroides Burch. Walafrida densiflora (Rolfe) Rolfe Ziziphus mucronata Willd. Zinnia peruviana (L.) L. Ziziphus zeyheriana Sond.

- Grasses Original vegetation Aristida bipartita (Nees) Trin. & Rupr. Aristida canescens Henrard The original vegetation is thought to be Aristida congesta Roem. & Schult. ssp. barbicollis typical Bankenveld (Acocks 1988) or Rocky (Trin. & Rupr.) De Winter Aristida congesta Roem. & Schult. ssp. congesta Highveld Grassland (Bredenkamp & Van Cynodon dactylon (L.) Pers. Rooyen 1996). Bredenkamp & Brown (1998) Diheteropogon amplectens (Nees) Clayton found a few relict sites which indicate that Elionurus muticus (Spreng.) Kunth the original vegetation on the shallow gra- Eragrostis chloromelas Steud. nitic soils of the Johannesburg Granite Dome Eragrostis curvula (Schrad.) Nees Eragrostis gummiflua Nees could have been a variant of the Monocym- Eragrostis plana Nees bium ceressiforme-Loudetia simplex Grass- Eragrostis racemosa (Thunb.) Steud. land (Bredenkamp & Brown 2003). This Eragrostis rigidior Pilg. vegetation is found in areas where little or no Heteropogon contortus (L.) Roem. & Schult. Hyparrhenia filipendula (Hochst.) Stapf disturbance is evident. Hyparrhenia hirta (L.) Stapf The herbaceous layer covers approximately Melinis repens (Willd.) Zizka Pogonarthria squarrosa (Roem. & Schult.) Pilg. 80 % and is dominated by the grasses Loude- Sporobolus africanus (Poir.) Robyns & Tournay tia simplex, Trachypogon spicatus, Schiza- Trichoneura grandiglumis (Nees) Ekman chyrium sanguineum, Monocymbium ceresiiforme, Digitaria monodactyla, Eragrostis - Forbs racemosa, Andropogon shirensis, Brachiaria Acalypha angustata Sond. serrata, Alloteropsis semialata, Bewsia biflo- Anthospermum hispidulum E.Mey. ex Sond. ra and Themeda triandra. Asparagus laricinus Burch. Asparagus suaveolens Burch. The woody layer consists mainly of a few Bidens formosa (Bonato) Sch.Bip. scattered individuals of the trees Rhus Bidens pilosa L. pyroides, R. leptodictya, Ziziphus mucro- Chamaecrista mimosoides (L.) Greene Cirsium vulgare (Savi) Ten. nata, the dwarf shrubs Protea welwitschii, Commelina africana L. Lopholaenia coriifolia, and the geoxylophyte Conyza albida Spreng. Parinari capensis that are locally prominent. Cucumis zeyheri Sond. The grasses Panicum natalense, Urelytrum Cyperus species agropyroides, Tristachya leucothrix, Cym- Elephantorrhiza elephantina (Burch.) Skeels Felicia muricata (Thunb.) Nees bopogon excavatus and Elionurus muticus Gazania krebsiana Less. are also abundant together with the forbs Geigeria burkei Harv. Cyanotis speciosa, Bulbostylis burchellii, Gomphocarpus fruticosus (L.) Aiton f. Crabbea acaulis, Anthospermum hispidulum Helichrysum nudifolium (L.) Less. Helichrysum rugulosum Less. and Senecio venosus. The grass Hyparrhenia Hermannia depressa N.E.Br. hirta is often present and may become more Hibiscus aethiopicus prominent at disturbed sites. Hypoxis rigidula Lactuca species This grassland is characterised by a high Ledebouria marginata (Baker) Jessop species richness with a patchy dominance of

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bredenkamp.indd 62 2006/10/15 10:51:03 PM Ba8 Olea europaea L. ssp. africana (Mill.) Ba7 P.S.Green IbI4b4 N Ib6 Ba9 Rhus lancea L.f. Ib7 Fa12 Ab2 Rhus leptodictya Diels Rhus pyroides Burch. Ib4 Ib6 Ziziphus mucronata Willd. Fa18 Bb2 Ab1 Ziziphus zeyheriana Sond. Ba44 Ab6 Fb14 Ab12 - Grasses Fa17 Bb1 Ab4 Ib41 Andropogon schirensis A.Rich. Ab11 Ba1 Aristida adscensionis L. Bb3 Aristida canescens Henrard Ba35 Aristida congesta Roem. & Schult. ssp. Ba36 congesta Ab7 Ib43 Bb3 Brachiaria serrata (Thunb.) Stapf Ab7 Cymbopogon excavatus (Hochst.) Stapf ex Burtt Davy Cymbopogon pospischilli (K.Schum.) C.E. # Hubb N HEKPOORT # Cynodon dactylon (L.) Pers. TIMEBALL HILL TIMEBALL HILL Digitaria brazzae (Franch.) Stapf HALFWAY HOUSE GRANITE Diheteropogon amplectens (Nees) Clayton

# # # Elionurus muticus (Spreng.) Kunth BLACK REEF # Eragrostis chloromelas Steud. WITWATERSRAND # MALMANI Eragrostis curvula (Schrad.) Nees MULDERSDRIF # Eragrostis racemosa (Thunb.) Steud. Harpochloa falx (L.f.) Kuntze Heteropogon contortus (L.) Roem. & GOVERNMENT # # Schult. # # # CENTRAL RAND Hyparrhenia hirta (L.) Stapf # TURFFONTEIN JEPPESTOWN Melinis repens (Willd.) Zizka MALMANI HOSPITAL HILL # # Monocymbium ceresiiforme (Nees) Stapf KLIPRIVIERSBERG KLIPRIVIERSBERG Panicum natalense Hochst. Schizachyrium sanguineum (Retz.) Alston Sporobolus pectinatus Hack. 30 0 30 60 Km Themeda triandra Forssk. Trachypogon spicatus (L.f.) Kuntze Trichoneura grandiglumis (Nees) Ekman Fig. 3. Land Types (above) and Geology (bottom) within the Tristachya leucothrix Nees Egoli Granite Grassland Tristachya rehmannii Hack - Forbs Acalypha angustata Sond. Aloe transvaalensis Kuntze various grass species and a large variety of Aloe greatheadii Schönland forbs (Louw 1970), representing a climax or Anthericum species Anthospermum hispidulum E.Mey. ex Sond. close to climax condition. Grazing by cattle Asparagus suaveolens Burch. is often found in this vegetation type, but the Aster bakeranus Burtt Davy ex C.A.Sm. dominance of sour grass species often results Babiana hypogea Burch. in a low nutrient status of the grass during Becium obovatum (E.Mey. ex Benth.) N.E.Br. Blepharis subvolubilis C.B.Clarke winter (Kerfoot 1987; Bredenkamp & Van Boophane disticha (L.f.) Herb. Rooyen 1996). Bulbostylis hispidula (Vahl) R.W.Haines Chascanum hederaceum (Sond.) Moldenke var. Typical species found in the original Egoli hederaceum Granite Grassland are indicated below: Chaetacanthus burchellii Nees Chlorophytum fasciculatum (Baker) Kativu - Trees and shrubs Crabbea acaulis N.E.Br. Acacia caffra (Thunb.) Willd. Crabbea angustifolia Nees Celtis africana Burm.f. Crassula capitella Thunb. ssp. capitella Elephantorrhiza elephantina (Burch.) Skeels Crinum bulbispermum (Burm.f.) Milne-Redh. & Gymnosporia buxifolia L. Szysyal Schweick.

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bredenkamp.indd 63 2006/10/15 10:51:03 PM Cucumis zeyheri Sond. or disturbed to such an extent that degradation Dicoma anomala Sond. proceeds beyond a threshold, then recovery is Eriosema cordatum E.Mey. Eulophia species very slow, due to reduced nutrient cycling Felicia muricata (Thunb.) Nees and decreased nutrient availability and the Gladiolus crassifolius Baker vegetation may change to another domain Gnidia capitata L.f. of attraction (Bosch 1989), different from Haplocarpha scaposa Harv. the original climax vegetation, representing Helichrysum aureonitens Sch.Bip. Helichrysum miconiifolia Hilliard a plagioclimax (Fig. 4). A change back to Helichrysum nudifolium (L.) Less. the original domain of attraction is unlikely Hermannia depressa N.E.Br. if not impossible in the short and medium Hypericum aethiopicum (Bret.) N.K.B. term. Due to the granitically derived shallow Hypericum lalandii Choisy nutrient poor soils these systems are sensi- Hypoxis hemerocallidea Fisch. & Mey. Hypoxis multiceps Buchinger ex Baker tive and intolerant to frequent impacts such Hypoxis rigidula Baker as heavy grazing, ploughing, trampling and Ipomoea obscura (L.) Ker Gawl. general domestic activities. Thus degradation Ipomoea ommaneyi Rendle occurs easily resulting in a change from the Justicia anagalloides (Nees) T.Anderson climax (high species richness) vegetation to Kohautia amatymbica Eckl. & Zeyh. Ledebouria ovatifolia (Baker) Jessop an anthropogenic Hyparrhenia hirta (low Ledebouria marginata (Baker) Jessop species richness) dominated vegetation type. Lotononis foliosa Bolus Mariscus congestus (Vahl) C.B.Clarke Very often Hyparrhenia species-dominated Neorautanenia ficifolius (Benth.) C.A.Sm. grasslands occur on ancient lands in the Pentanisia angustifolia (Hochst.) Hochst. Central Variation of the Bankenveld (Acocks Pentanisia prunelloides Klotzsch ex Eckl. & 1988) and in the surroundings of archaeo- Zeyh.) Walp. Raphionacme hirsuta (E.Mey.) R.A.Dyer ex logical sites (Bredenkamp & Brown 2003), E.Phillips where the inhabitants had a mosaic of cul- Scabiosa columbaria L. tivated lands and grazing of domestic stock. Schistostephium crataegifolium (DC.) Fenzl ex The more recent European settlers also had Harv. a profound effect on the natural vegetation Senecio venosus Harv. Tephrosia capensis (Jacq.) Pers. as they developed the cities of Johannesburg Triumfetta sonderi Ficalho & Hiern and Pretoria following the discovery of gold Tulbaghia acutiloba Harv. more than a century ago. It seems that the Turbina oblongata (E.Mey. ex Choisy) A.Meeuse degraded sites developed into Hyparrhenia Ursinia nana DC. species-dominated grasslands, which tend to Vernonia natalensis Sch.Bip. ex Walp. Vernonia oligocephala (DC.) Sch.Bip. ex Walp. be stable for a very long time. Moll (1965) and Smits et al. (1999) also indicated that Hyparrhenia species-dominated tall grass- Origin of the current vegetation lands are anthropogenic in origin. The shallow, nutrient-poor soils provide a habitat suited to the climax vegetation as dis- Importance cussed previously. Some nutrients are avail- able in the topsoil, supplemented from fallen The substrate of the Johannesburg Granite leaf litter and decomposition, and also from Dome (Halfway House Granites, Fig. 3) is ashes of burned herbaceous layer (if there suitable for development. The area is well was a fire). Nutrients are quickly utilised situated between Johannesburg, the economic by plants and are furthermore also quickly powerhouse of South Africa, and Pretoria leached from the very coarse sandy soils. the administrative capital of the country. There is an enormous demand for develop- Nutrient cycling is therefore very rapid. able land in this area, which has resulted in The system is quite stable and fairly predict- the loss of large tracts of the original Egoli able without much change caused by normal Granite Grassland. Due to general distur- droughts or grazing. However, if overgrazed bance, ploughing and degradation, an esti-

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bredenkamp.indd 64 2006/10/15 10:51:04 PM mated 60 % of the remaining original Egoli Domain of attraction I Granite Grassland has been transformed Domain of attraction II Original Egoli to Hyparrhenia hirta dominated grassland. Granite Grassland Only relatively small scattered pockets of Plagioclimax the original grassland are still intact and these are considered rare and highly threat- Threshold ened. Due to its high species richness and Sere restricted occurrence, this endemic grassland Hyparrhenia dominated grassland has a high conservation value. Sere Furthermore, the bottomland areas and wet-

lands within the Egoli Granite Grassland = Degradation provide suitable habitat for various sensitive Pioneer fauna species such as the Grass Owl Tyto = Succession capensis (Red Listed), Marsh Sylph Metisel- la meninx (Vulnerable), and the Giant Bull- Fig. 4. A model indicating degradation of original frog Pyxicephalus adspersus (Near Threat- Egoli Granite Grassland climax and succession ened). towards a Hyparrhenia hirta dominated vegetation type.

Conclusion important since it is unlikely that the transformed anthropogenic grassland will return Egoli Granite Grassland is a poorly con- to the original climax vegetation. served, severely transformed, highly fragmented and degraded vegetation type. It Since Egoli Granite Grassland is endemic to is estimated that only 22 % of the original Gauteng, its protection is both a provincial extent of Egoli Granite Grassland remains and national priority. It also forms part of in its original state. Many of these remnant a global ecoregion in crisis, an area where areas are likely to be destroyed in the near biodiversity and ecosystem services are at future due to previously authorised develop- greatest risk and focused on-the-ground con- ments (e.g. Cosmo City to the north-west servation action are required (Hoekstra et al. of Johannesburg) or illegal activities. It is 2005). therefore essential that any viable remnant patch of original Egoli Granite Grassland is conserved. References

Areas associated with transformed grassland, Acocks, J.P.H. 1988. Veld types of South Africa. 3rd where Hyparrhenia hirta is dominant and ed. Memoirs of the botanical Survey of South species richness is low, have a low value with Africa 57: 1–146. Barnes, K.N. (ed.) 2000. The Escom Red Data Book respect to achieving the national conserva- of Birds of South Africa, Lesotho and Swaziland. tion target for Egoli Granite Grassland. It Johannesburg: BirdLife South Africa. should be noted however, that Hyparrhenia Bosch, O.J.H. 1989. Degradation of the semi-arid hirta dominated grassland may be valuable grasslands of southern Africa. Journal of Arid for the conservation of sensitive fauna, e.g. Environments 16: 165–175. Bredenkamp, G.J & L.R. Brown. 1998. A vegetation Grass Owl (Tyto capensis) and Giant Bull- assessment of the northern areas of the Northern frog (Pyxicephalus adspersus). Metropolitan local Council. Pretoria: Ekotrust A mixture of various grasses and high forb cc. Unpublished report. Bredenkamp, G.J & L.R. Brown. 2003. A reap- diversity renders the original Egoli Granite praisal of Acocks’ Bankenveld: origin and diver- Grassland with a high conservation value and sity of vegetation types. South African Journal of conservation of remnant areas is especially Botany 69(1): 7–26.

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B redenk a mp , G.J. & N. van Rooyen. 1996. Rocky oirs on the Agricultural Natural Resources of Highveld Grassland. P. 39. In: Low, A.B. & South Africa 4: 1–342. A.G. Rebelo (eds.). Vegetation of South Africa, Land Type Survey Staff. 1985. Land types of the Lesotho and Swaziland. Pretoria: Department of maps 2628 East Rand. 2630 Mbabane. Memoirs Environmental Affairs & Tourism, on the Agricultural Natural Resources of South Fahrig, L. 2003. Effects of habitat fragmentation on Africa 4: 1–261. biodiversity. Annua. Review of Ecology Evolu- Land Type Survey Staff. 1987. Land types of the tion and Systematics 34: 487–515. maps 2526 Rustenburg, 2528 Pretoria. Memoirs Gauteng, 1997. State of the Environment in Gau- on the Agricultural Natural Resources of South teng: A preliminary report. Gauteng Department Africa 8: 1–391. of Agriculture, Conservation and Environment. Louw, W.J. 1970. Klipveld studies 1: Checklist of Unpublished report, CSIR Environmentek. vegetation. Journal of South African Botany 36: Kerfoot, O. 1987. The geology, physiography and 199–206 vegetation of the Witwatersrand floral region. Minter, L.R., M. Burger, J.A. Harrison, H.H. Pp. 1-7. In: Lowrey, T.K. & S. Wright (eds.). Braack, P.J. Bishop & D. Koepfer (eds.). 2004. The flora of the Witwatersrand Volume 1: The Atlas and Red Data Book of the Frogs of South Monocotyldonae. Johannesburg: Witwatersrand Africa, Lesotho and Swaziland. Washington, DC: University Press. Smithsonian Institution. Moll, E.J. 1965. An account of the plant ecology of Grobler, C.H. 2000. The vegetation ecology of the upper Umgeni Catchment. MSc thesis, Uni- urban open spaces in Gauteng. MSc thesis, Uni- versity of Natal, Pietermaritzburg versity of Pretoria, Pretoria. Mucina, L., Rutherford, M.C. & L.W. Powrie Grobler, C.H., G.J. Bredenkamp, L.R. Brown. (eds.). 2005. Vegetation map of South Africa, 2002. Natural woodland vegetation and plant Lesotho & Swaziland, 1:1 000 000 scale sheet species richness of the urban open spaces in Gau- maps. Pretoria: South African National Biodi- teng, South Africa. Koedoe 45: 19–34 versity Institute. Grobler, C.H., G.J. Bredenkamp, L.R. Brown. Smits, N.A.C., G.J. Bredenkamp, L. Mucina & J.E. 2006. Primary grassland communities of urban Granger. 1999. The vegetation of old fields in open spaces in Gauteng, South Africa. South Transkei. South African Journal of Botany 65: African Journal of Botany 72: 367–377. 414–420 Hoekstra J.M., T.M. Boucher, T.H. Ricketts & Weather Bureau. 2000. Prints of the climate sta- C. Roberts. 2005. Confronting a biome crisis: tistics of the Johannesburg Leeukop, Pretoria global disparities of habitat loss and protection. Forum WB, Johannesburg Joubert Park and Ecology Letters 8: 23–29. Krugersdorp Kroningspark weather stations. Land Type Survey Staff. 1984. Land types of the Pretoria: Department of Environment Affairs maps 2626 Wes-Rand, 2726 Kroonstad. Mem- and Tourism.

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