608 Forestry Quarterly 



The soil is fertile but water is scarce and the scanty rainfall 

 is carried away rapidly by the many torrential beds which cut 

 the surface. The rainfall has averaged at different points 8 to 

 14 inches annually, 60 to 75 per cent of which falls in the summer. 

 The temperature varies from a minimum of 20° F. to a maximum 

 of 110" F. There are no trees except scattered Acacia horrida 

 along the few river banks . 



5. Upper Region. Lying directly north of the Karroo is a great 

 region, almost 300 miles square, 3500 to 4,000 feet in elevation, a 

 vast monotonous plain broken only by isolated, flat-topped moun- 

 tains or rugged hills. 



The rainfall here has averaged annually at different points 6 to 

 27 inches, of which 65 to 75 per cent comes in the simimer. Coupled 

 with the absence of rainfall, the range of temperature, together 

 with the sudden changes, is very severe for plant growth. The 

 minimum is 14° F. to 20° F. at different stations and the maximum 

 97° F. to 112° F. There are a few stunted bushes on sheltered 

 slopes and in the valleys, but absolutely no trees, excepting an 

 occasional Salix capensis along the Orange River, which is the chief 

 drainage coiirse for the region. 



6. Kalahari. There remains the great continental plateau, 

 3500 to 4,000 feet high, an area of 700,000 square miles comprising 

 almost the whole of Orange River Province, the Transvaal and 

 Bechuanaland, a large portion of the North-western Cape Pro- 

 vince, and much territory outside the Union of South Africa. The 

 general slope is westward to the Orange River ; a few streams break 

 through eastward to the Indian Ocean. Many mountains rise 

 from the plateau, reaching 6,000 to 10,500 feet. 



The rainfall varies from almost nothing in the sandy western 

 boundary districts to 20 inches along the east and southwest and 

 40 inches on some of the moimtain ranges, particularly in the 

 northern Transvaal. Eighty per cent of the precipitation occurs 

 in the summer. The temperature drops to a minimimi of 16° 

 F. to 20° F. and rises to 96° F. to 11 2° F. The changes are very sud- 

 den and frosts are dangerous to vegetation in many districts. 



The mountains are grass topped. Westward extend hundreds of 

 miles of high veld or grass, which merges into scrubby bush veld 

 and savannah forest. The only important forests are in the 

 limited regions of greater rainfall, covering only a few thousand 

 acres in the ravines and on the slopes lying to the east and south- 

 east of the mountains. 



