The reserve is situated mainly on the plains to the west of the Lebombo Mountains, with a sharp increase in altitude from the plains (150 m a.s.l.) to the summit of the mountain (730 m a.s.l.). The geology consists of basalt on the plains, while the Lebombo Mountains consists of rhyodacite.
in the region
The mean annual rainfall for the Pongola weather station is 638 mm, varying from a potential minimum of 488 mm during dry years up to 871 mm and more per annum during exceptionally wet years. The mean annual rainfall for other rainfall stations in the region varies from 568 mm to 925 mm. The mean annual temperature of the region varies from 20.7°C to 23°C. The extreme minimum temperatures vary from -2.4°C at Mkuze to 8.4°C at Pongolapoort. The area is generally frost-free.
The broad vegetation types for the region are the Zululand Lowveld on the basaltic plains, the Southern Lebombo Bushveld of the Lebombo Mountains, and small areas of Scarp Forest. The Lebombo Summit Sourveld falls mostly outside the Nsubane area.
Thirteen plant associations/communities and two subcommunities were distinguished for the Royal Jozini Private Game Reserve area. These are:
- Berchemia zeyheri – Croton sp. – Searsia pentheri dense bushveld
- Combretum apiculatum-Aristida meridionalis bushveld and woodland on rocky outcrops
- Acacia nigrescens-Sclerocarya birrea-Eustachys paspaloides woodland
- Combretum apiculatum-Acacia nigrescens-Boscia albitrunca bushveld and woodland
- Acacia nilotica-Ischaemum afrum open woodland
- Acacia borleae-Acacia senegal var. rostrata low bushveld and thickets
- Acacia nigrescens-Dichrostachys cinerea bushveld and open woodland
- Acacia nigrescens-Sclerocarya birrea open to dense bushveld
- Acacia luederitzii-Euclea undulata thickets
9a. Acacia luederitzii thickets
9b. Euclea undulata thickets
- Acacia grandicornuta-Euclea schimperi dense bushveld, thickets and bushclumps
- Acacia xanthophloea woodland
- Acacia ataxacantha thickets
- Cynodon dactylon grasslands
The mean ecological and economical grazing capacity for Royal Jozini was calculated from the capacities of the individual plant communities. The economical grazing capacity at a mean annual rainfall of 680 mm is calculated at approximately 1 LAU (Large Animal Unit or equivalent of a 1000lb animal per 6.5 hectares. This translates to the reserve sustainably providing grazing to a 1000lb animal per 6.5 hectares which is an exceptional carrying capacity. The recommended browsing capacity is 10 – 12 BU (Browser Units) per 100 ha, again very high providing large game numbers of both grazers and browsers adequate food throughout the seasons.
Wildlife suitable for the area are the black rhinoceros, blue wildebeest, buffalo, bushbuck, bushpig, eland, elephant, grey duiker, hippopotamus, impala, klipspringer, kudu, nyala, plains zebra, red duiker, reedbuck, warthog, waterbuck and white rhinoceros. Some habitats on Royal Jozini Private Game Reserve are suitable for species with marginable historical distributions such as the blue duiker, giraffe, mountain reedbuck, Sharpe’s grysbok, steenbok, suni and tsessebe.