32 



administration. And now we propose to establish irrigation systems, neglecting to- 

 provide first for those conditions which assure a regulated water supply, namely, by 

 forest preservation." This paper led to the appointment of a Committee to urge the 

 importance of these matters on the President and Congress of the United States and on 

 the Premier and Parliament of Canada. 



FOBESTS AND RIVERS. Torrents cause floods and the silting up of navigable rivers 

 and of their estuaries. Sometimes, the sand is brought down to the sea, forming sand- 

 banks at the mouth, which are spread along the coast by currents and wave action, filling 

 harbours and channels to the detriment of navigation. Thus an increased discharge of 

 sand from the mouth of the Umlazi or that of the Umkomanzi, could only tend to aid 

 the formation of the Durban sand-bar, though other more powerful causes acting 

 contrariwise might mask the effect. In the same way, the denudation of the Umzimkulu 

 basin which is now in active progress, cannot tend to improve the estuary at Port 

 Shepstone. 



EFFECT OF FORESTS ON WIND. Not only do forests shield the ground from the 

 destructive action of water, but tbej r also often prevent injurious effects of the wind. 

 Acting as windbrakes, they protect adjacent cultivated land from the dessicating 

 effect of hot winds, instances are recorded of arid tracts rendered cultivable by 

 the planting of protective belts and conversely the destruction of forests has doomed 

 some fertile regions to sterility.* Planters along the coast are well aware of the 

 value of fringes of forest in protecting tea and coffee plantations. Forests also 

 protect sandy soil from wind action. Sand drifts on the south-western coast of 

 France, and on the Baltic coast, which formerly buried villages and fields, and proved 

 locally as great a scourge as torrents were in the south of France, have now been 

 effectively arrested by plantations of Cluster pine, and a great extent of land reclaimed 

 for agriculture. The French Landes which consisted of low-lying sand wastes, marshy 

 and fever stricken, have been converted into productive districts ; the extent of land thus 

 reclaimed by forest culture is estimated by Bagneris at 4,000 square miles, or over one- 

 fifth of the area of Natal. Conversely, in Sologne, the destruction of forests on sandy 

 ground has transformed one of the most fertile provinces of medieval France into a 

 sterile and unhealthy region. At the Cape, about four square miles of a belt of sand 

 running from False to Table Bay, across the isthmus over which the railway had to pass, 

 have been successfully reclaimed by mixed plantations of Acacia saligna, Hakea suaveolens, 

 Pinus pinaster and P. pinea. 



SANITARY INFLUENCE OF FORESTS. The power of forests to increase the salubrity 

 of the atmosphere is held, by Italian observers, to have been proved. Forests seem ta 



* Vide Marsh, I.e., pp. 157-165. 



