In this connection, the attitude of the engineer to the afforestation question. is an important matter. Afforestation of areas unsuitable for crops is undoubteilly very desirable, Deterioration of streams by eroded material is undoubtedly increased. by deforestation. On the other hand, the effects of artificial afforestation on rainfall and flood storage are indirect, slow, limited, and uncertain; and' the economics of afforestation. (including the necessary policing) are diffiedlt. It, isto Jo. feared that the larger benefits, of reafforestation are so remote' that, utu the finances jot China' ave"in_a very flourishing condition, it will not receive very serious. attention. To the engineer, it is a palliative for charmel doterjoration, if done on a very large scale, but'is pethips of most interest to him as a source for) a regular supply of timber.; As long 'a8, the great timber supplies of America and the East Indies remain available at low prices, the pro-specta for timber preservations and proper replanting scheme in China are rather poo!
In this connection, attention thight well be drawn to Dr. Eng-Iwender's "hypotheses ai to the relation between afforestation, civilization and desert encroachment.
1 understand him rightly, decrease of rainfall tends to follow upon the complete removal of vegetation, so that the need is not 8 much to preserve forests as to preserve a vegetation cover. If this is correct, it suggests a new policy by which tree-cutting should only be allowed when guaranteed that continuous agricul. ture (or reforesting) will follow, The important factor is the tra ration of water by the plants, whether they be trees or cereals, but it must also be considered when ther useful crops will grow deforested areas. In some cases, the soil in not good enough to feed short-rooted plants,
Text read from the printed page and cleaned; old type leaves the occasional error.