A forest means wealth, the forests of tropical Africa are perhaps its greatest wealth. Consider the moisture - conserving function of a forest even a dry forest. The knowledge of African forests is unsurpassed, is of the opinion that one of the most important functions of the dry forests ''is to preserve the environment of dry Africa from a deterioration that would aggravate the effects of the severe climate''. Certainly nobody who has seen a dry forest degraded by drought, uncontrolled cutting, fire and other abuse, is likely to dispute this opinion.
Then, too, forest suffer less from either dry spells or torrential rains than unforested areas do, and they conserve rain-water and channel it into the soil. The higher run-off of rain-water from land shorn of its natural vegetation means not only little carry-over of moisture for growing plant but also less "topping-up" of the well and spring water supplies on which forest dwellers chiefly depend in the dry season. The minimum forest cover needed in East Africa to maintain a proper hydrological regime is around eight per cent of the total land area". The figure for other dry forest areas in tropical Africa is probably not very different. Low as it is, it is a figure far above that attained in many occupied areas.
The provision of shade and shelter is another important indirect function of the forests, almost as vital for some crops as the assurance of a stabilized moisture supply. No less than four of the biggest revenue - earning crops of tropical African plants which cannot flourish if exposed to the full glare of the vertical sun, or to drying winds. Cocoa needs all the shade it can get from taller trees. Tea needs almost as much. Coffee is not quite so fastidious, but it is all the better for some shelter when it grows below about 4,500 feet(1372 metres). So, too, is the banana, though more as protection against strong wind than sunlight. Nor is this need confined to cultivated crops. It is necessary for the maintenance of the forest itself. Few species of forest tree, in or out of the topics, are so hardy that they can survive a long exposure to an alien deforesed environment.
Then, too, forest suffer less from either dry spells or torrential rains than unforested areas do, and they conserve rain-water and channel it into the soil. The higher run-off of rain-water from land shorn of its natural vegetation means not only little carry-over of moisture for growing plant but also less "topping-up" of the well and spring water supplies on which forest dwellers chiefly depend in the dry season. The minimum forest cover needed in East Africa to maintain a proper hydrological regime is around eight per cent of the total land area". The figure for other dry forest areas in tropical Africa is probably not very different. Low as it is, it is a figure far above that attained in many occupied areas.
The provision of shade and shelter is another important indirect function of the forests, almost as vital for some crops as the assurance of a stabilized moisture supply. No less than four of the biggest revenue - earning crops of tropical African plants which cannot flourish if exposed to the full glare of the vertical sun, or to drying winds. Cocoa needs all the shade it can get from taller trees. Tea needs almost as much. Coffee is not quite so fastidious, but it is all the better for some shelter when it grows below about 4,500 feet(1372 metres). So, too, is the banana, though more as protection against strong wind than sunlight. Nor is this need confined to cultivated crops. It is necessary for the maintenance of the forest itself. Few species of forest tree, in or out of the topics, are so hardy that they can survive a long exposure to an alien deforesed environment.
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