132 Report S.A.A. Advancement of Science. 



As already mentioned, the kind of tree used for plantation \vork 

 materially affects the result from a climatic point of view, and in 

 this the quick-growing and consequently rapidly remunerative kinds 

 are the least beneficial. Slow-growing species, producing dense 

 canopy and much humus are the most useful climatically ; hence, 

 since these are so long in bringing in returns that the private planter 

 omits them from his plantation, there is the more reason why the vari- 

 ous Governments should act energetically in forming large plantations 

 of these kinds, even if paid for from loan funds as is done in Cape 

 Colony, on the principle that it is expenditure which will ultimately 

 be remunerative. Of that there cannot be any doubt if the work is 

 skilfully and economically performed, even apart from the question 

 of climate, but the climatic importance is so great as to practically 

 outweight all other considerations and warrant even huge expendi- 

 ture. The drying out of South Africa is at present going ahead 

 at an enormous and rapidly increasing pace, much accelerated by 

 the methods of pastoral agriculture in use; cattle diseases have 

 rendered that form of industry unremunerative or doubtfully and 

 irregularly remunerative ; intensive culture and rotation-grazing are 

 steps towards production w'ithout prejudicial effect on the climate. 

 but it is in plantation work, and especially Government plantation 

 works of slow-growing and humus-producin"- kinds of trees that anv 

 guarantee (or even precaution) against increasing desiccation lies.. 



