516 J- W. BEWS. 



(7) As a result of man's interference other associations 

 replace the natural veld grasses (Aristida j unciform is, 

 Eragrostis curvula, Cynodon dactylon, Sporobolus 

 i n d i c u s ) . 



(8) When the veld is cultivated a variety of weeds occur, 

 at tirst mostly annuals. If such ground is allowed to revert 

 to veld, the perennials gradually replace the annuals and the 

 grasses regain dominance. 



2. THE BUSH FORMATION. 



In the tree growth even more than in the grasses there is 

 a marked distinction between the high veld and the low veld 

 regions. In the former we find the close type of bush, in the 

 latter the very xerophytic isolated thorn trees. The high 

 veld type of rocky hillside formation is intermediate between 

 those two. 



(1) The Close Bush (Midland Type). 



This always grows in the situations where there is a 

 maximum deposition of moisture — the south-eastern slopes. 

 It faces the rain-bearing clouds and is sheltered from the hot, 

 dry winds. The fact that the bush is cooler during the day- 

 time than the surrounding veld increases the precipitation, 

 and the colder air will How outwards from the bush, so that 

 the veld in the neighbourhood also Ijenefits. On the other 

 hand, there is less rapid cooling in the bush at night, so that 

 frosts inside the bush are rare. 



The soil is similar to that of the Andropogon associations 

 of the veld, and if the trees were absent the topography 

 would be of a much less stable type. Often the bush- 

 covered slopes are rocky and similar to those rocky hillsides 

 which, when they do not face south-east, are covered hj the 

 more xerophytic type of plant formation described on p. 526. 

 Much of the type of veld at present made up of Andropogon 

 associations with numerous associated plants was at one time 

 bush. The bush is at the present time retrogressive. 



