FORESTRY 1 97 



available in reports such as that on the plains region of the United 

 States by the United States Forest Service (1935), rnay have 

 important applications in parts of Africa. 



Sierra Leone has only about 840 square miles of reserved forest, 

 representing 3 per cent of the total land area. The unreserved 

 virgin forest is being reduced in area every year, and the secondary 

 forest is steadily deteriorating. Areas of regrowth of increasing size 

 are regularly cut and reduced in quality. In the prevailing climate, 

 soil without forest cover is reduced to sheet laterite which is of very 

 poor value for cultivation purposes. Regeneration of cleared land 

 with the use of Gmelina, a very quick-growing tree introduced from 

 India for timber purposes, is under trial at the agricultural re- 

 search station of Njala and in some forest reserves. The system 

 resembles taungya, but the tree in question forms such a dense 

 canopy that other vegetation cannot grow beneath it, with the 

 result that soil wash is serious on sloping land. 



In the Anglo- Egyptian Sudan the burning of thorn and savannah 

 forests for shifting cultivation presents a difficult problem, particu- 

 larly since fire damages the gum-tree [Acacia Senegal), from which 

 large numbers of Arabs obtain their livelihood. The baobab 

 [Adansonia digitata), which grows to a circumference of forty feet 

 and over, is invaluable in certain parts of the Central Sudan where 

 it is used for storing water. Some 30,000 of these trees are filled 

 with water and form the basis of village life. Together with its 

 capacity for storing water the baobab provides ideal situations 

 for the breeding of mosquitoes, and for this reason is regularly 

 destroyed in parts of Africa. 



FOREST BOTANY, ECOLOGY, AND STOCKTAKING 



Active steps are being taken by the Imperial Forestry Institute, 

 in co-operation with local officers, to advance our knowledge of 

 the component species of the forests, which is at present far from 

 complete. This is being done by the preparation of check-lists 

 (Imperial Forestry Institute 1935-7), leading to annotated cata- 

 logues and finally to regional forest floras. It is unlikely that the 

 final stage will be reached in any country for some time to come, 

 but considerable progress can be recorded. The first check-list 



