**4.2 Grass diversity**

A total of 73 grass species where collected on Platberg with 29 species using C3 metabolism, and 30 species using C4 metabolism, the remaining 14 species use mixed C3/C4 metabolism (Figure 4). The C3/C4 split is almost equal however, an examination of grass community structure on Platberg shows grasses using C4 metabolism dominate.

Only one grass *Helictotrichon longifolium* and the mountain bamboo *Thamnocalamus tessellatus*, uses C3 metabolism, with *Digitaria monodactyla* and *Pennisetum sphacelatum* showing mixed C3/C4 metabolism, the majority of the communities and species show the use of C4 metabolism, which represents 83% of the grass community structure on Platberg.

Fig. 4. Ratio of grass metabolic pathways on Platberg.

#### **5. Discussion**

#### **5.1 Forest Biome affinities**

The entire forest biome in South Africa is composed of a number of fragmented forest patches, either continuous as in the Southern Afrotemperate Forests of the Tsitsikamma region of the western Cape, fragmented Southern Mistbelt Forest for the Eastern Cape and Northern Afrotemperate Forests in the Drakensberg, or contiguous Northern Mistbelt mountain patches in Mpumalanga and Limpopo Provinces, or disjunct, scattered Northern Afrotemperate Forests growing in the Magaliesberg in the North Western Province (Von Maltitz 2003, Mucina & Rutherford 2006).

These relictual elements of the Afrotemperate Forests (von Maltitz 2003) are all regarded as depaupered or 'biogeographically' eroded as well as previously linked as recently as the Pleistocene > 2 My BP (Scott et al., 2003). Today they are fragmented and are found as refugia in inselbergs (Brand et al., 2009) or relictual scarp situations on elevated ranges (Von Maltitz 2003; Mucina & Rutherford 2006). Afrotemperate forests have also retreated into kloofs (narrow, incised canyons) or have lost numerous Afrotemperate species through episodes of climate change, encroachment by Grassland and Savanna Biomes, or reduction by fire and grazing. Fire in particular is important in shaping the modern appearance and distribution of the forest (Mucina & Rutherford 2006), patches of which are found below

On a species level, succulent families using CAM pathways total 278 species and 122 genera **(Table 1).** This accounts for 44.6% of the total genera and 42% of the total species found on

A total of 73 grass species where collected on Platberg with 29 species using C3 metabolism, and 30 species using C4 metabolism, the remaining 14 species use mixed C3/C4 metabolism (Figure 4). The C3/C4 split is almost equal however, an examination of grass community

Only one grass *Helictotrichon longifolium* and the mountain bamboo *Thamnocalamus tessellatus*, uses C3 metabolism, with *Digitaria monodactyla* and *Pennisetum sphacelatum* showing mixed C3/C4 metabolism, the majority of the communities and species show the use of C4 metabolism, which represents 83% of the grass community structure on Platberg.

The entire forest biome in South Africa is composed of a number of fragmented forest patches, either continuous as in the Southern Afrotemperate Forests of the Tsitsikamma region of the western Cape, fragmented Southern Mistbelt Forest for the Eastern Cape and Northern Afrotemperate Forests in the Drakensberg, or contiguous Northern Mistbelt mountain patches in Mpumalanga and Limpopo Provinces, or disjunct, scattered Northern Afrotemperate Forests growing in the Magaliesberg in the North Western Province (Von

These relictual elements of the Afrotemperate Forests (von Maltitz 2003) are all regarded as depaupered or 'biogeographically' eroded as well as previously linked as recently as the Pleistocene > 2 My BP (Scott et al., 2003). Today they are fragmented and are found as refugia in inselbergs (Brand et al., 2009) or relictual scarp situations on elevated ranges (Von Maltitz 2003; Mucina & Rutherford 2006). Afrotemperate forests have also retreated into kloofs (narrow, incised canyons) or have lost numerous Afrotemperate species through episodes of climate change, encroachment by Grassland and Savanna Biomes, or reduction by fire and grazing. Fire in particular is important in shaping the modern appearance and distribution of the forest (Mucina & Rutherford 2006), patches of which are found below

structure on Platberg shows grasses using C4 metabolism dominate.

Fig. 4. Ratio of grass metabolic pathways on Platberg.

Platberg.

**4.2 Grass diversity** 

**5. Discussion** 

**5.1 Forest Biome affinities** 

Maltitz 2003, Mucina & Rutherford 2006).

Van Reenen's Pass 60km east of Platberg, Royal Natal National Park to the west and the main Drakensberg at Qwa-Qwa to the south (Figure 5).

The highest altitude Afrotemperate *Podocarpus* forest in South Africa grows on Nelsons Kop at 2 230 m (Von Maltitz 2003), an inselberg about 20 km northeast of Platberg, and as with the forest patch on Platberg, it is located on the cool south-eastern side, below the basalt on the Clarens Formation sandstones. Other Northern Afrotemperate Forest affinities are found to the south, in the Fynbos Biome, and the Savanna Biome mountains to the north (von Maltitz 2003; Mucina & Rutherford 2006).

Fig. 5. *Podocarpus* forest patches below the Clarens Formation sandstone confined to fire protected gullies of the Drakensberg and Great Escarpment.
