rKESIBENTIAL ABUKESS SECl'IOX C. 63 



ami Yeg'etalive conditions, while abuse of the forest and veld 

 produces a destructive down-grade tendency, not onlj^ locally, 

 but for hundreds of miles away. We see in many places that, 

 when once that down-grade tendency is started, its natural 

 direction is to go steadily from l)ad to worse, and when we 

 connect this with the fact that the above-mentioned cycles 

 lead up to extreme desiccation during' the later years of the 

 dry period even under present conditions, we cannot help 

 seeing- that under continued grass burning* and forest destruc- 

 tion that desiccation must not onlj- become more intense 

 annually, but that toward the end of each dry period it must 

 become so much more intense on each occasion that the killing' 

 limit for many species must sooner or later be reached, and 

 tliat even where grass-veld now exists, especially overberg, 

 tliat must sooner or later be replaced by karroo-veld. Such a 

 change in the vegetation naturally has a reflex action on the 

 climate, which, aided by the continental position of that high- 

 veld, with extremes of insolation and radiation, must further 

 affect the vegetation. 



The powerful flywlieel of natural serjuence, once set in vigor- 

 ous motion, is beyond the power of man to stop, as is evidenced 

 in Northern Africa and in Arabia ; but South Africa is still at 

 a stage in which that flywheel may be started, either in the 

 direction of afforestation and grass protection, leading to 

 upward plant succession, accompanied by general vegetative 

 and climatic imin'ovement, or in the direction of veld fires, 

 forest destruction and down-grade vegetation, reacting on the 

 (dimate, which again further reacts on the vegetation, until at 

 last the continent is past redemption, as some parts of it now 

 are, and mankind as well as the fauna and flora must die a 

 natural dei.th. 



Do not let anyone suppose that what I have had to say 

 goes in any way against the i)roposals now being urged in 

 reference to bringing the Cunene and the ( Jkavanga rivers into 

 or through the Kalahari. The intention in each case is the 

 same, namely, to increase the absolute humidity of the 

 atmosphere, and so aid plant succession upward instead of 

 downward. Everything done in this direction liel]is, while the 

 absence of repressive action in regard to grass Inirning and 

 other causes of erosion is quite as serious and as disastrous to 

 the general welfare of South Africa as is the drying up of the 

 Etosha and other lakes. These two causes acting together 

 threaten the habitable existence of South Africa as a whole. 

 To some I may appear in all this to be particularly pessimistic. 

 I deny that charge, however, and wish to repeat that this is a 

 warning given before it is too late to turn the tide, a warning 

 in which all are interested, whether farmers or townsmen, since 

 if the farmer eventually cannot exist the townsmen suffer also. 



I haA'e tried to show in what directions changes in the flora 

 are taking place and are to be expected, apart from cultural 

 readjustments, and what causes are at work producing these 

 changes, and I strongly urge protective action, alike by the 

 Governments and bv the individuals; but wliile not delaving- 



