79 



: 

 capable of freely regenerating and perpetuating itself by natural means. This appears to 



be an extreme view, only true of species introduced from a dissimilar climate. When the 

 climatic conditions are favourable, exotic trees may become acclimatised ; that is to say 

 that if the species is not already fully adapted to the climate and the soil, it produces a 

 better fitted variety, after a number of generations. Natural reproduction by self-sown 

 seedlings is the test of acclimatisation ; thus the Syringa, though not indigenous to the 

 country, reproduces itself freely, and is found apparently wild in some parts of South 

 Africa. 



If we want to plant trees for their climatic effect, there is no doubt that it is 

 preferable to use native species, which have taken ages to adapt themselves to the 

 circumstances and climate of the country, and fulfil at present their function better than 

 any substituted foreign species possibly could. Though even then, a plantation will take 

 centuries to produce that thick carpet of hygroscopic soil which gives so great a value to 

 the natural forest ; and the conservation of the latter will thus be of greater general 

 utility than the creation of even a larger area of artificial forest. 



But if we want to grow trees for the sake of timber, there is no advantage in 

 restricting our choice to the native species. Many exotic species have already been found 

 by experience to be admirably suited to the country or its climate, while among our 

 woods, few have been proved to be of sufficiently fast growth to be cultivable at a profit, 

 and their culture should, at first, be undertaken on an experimental scale only. 



The native kinds of wood that should be tried in plantations are : Outeniqua 

 Yellowwood, Stinkwood, White Pear, Hard Pear, and Sneezewood. Outeniqua Yellow- 

 wood appears to be of moderately fast growth, and as a lumber-wood, it is the best we 

 have. The other woods are all harder. Stinkwood is an exceedingly valuable species, of 

 fast growth, and reproducing itself freely both from seed and shoots or suckers ; the wood 

 is adapted to almost every use. White Pear is a hard close-grained wood also of fast 

 growth, much sought for wagonwood. Hard Pear and Sneezewood do not appear to be 

 of very slow growth, and both yield hard woods, almost indestructible, that are highly 

 esteemed in South Africa. 



INFLUENCE OF CLIMATE ON THE DISTRIBUTION OF TREES. In introducing exotic, or 

 even indigenous, trees, in new regions, it is essential to choose species suited to the 

 climate. The influence of climate, on trees, is much greater than that of soil, and many 

 species which will thrive in almost any soil and with varying supplies of moisture, can 

 only grow in a zone with certain definite conditions of temperature. There is for each 

 species a central climate where it flourishes best, the fertility of the soil and the supply 

 of moisture being otherwise equal ; as it recedes from this central climate, either through 

 changed latitude or elevation, it becomes gradually more stunted and scarce ; and finally 

 disappears beyond certain limits which determine the geographical and altitudinal range 



