GOLD COAST REPORT ON FORESTS. 65 



The main factor determining the prevalence of any one type 

 in ti particular locality is the amount of rainfall and its distribu- 

 tion through the various seasons of the year. Where the dry 

 season is long and pronounced the majority of the plants have ac- 

 quired a very marked deciduous habit, even when the total rainfall 

 is otherwise heavy. 



Secondary (edaphic) influences are brought about by the char- 

 acter of the soil, and mainly depend on its capacity for retaining 

 moisture. These influences become very important, however, in 

 districts where the total annual rainfall is small, say 40 inches or 

 less, and give rise to the most pronounced types of dry vegetation 

 (xerophilous thorn scrub and dry open savannahs) to be met with 

 in the Hinterland. 



In Western Ashanti the transition between the moist, tropical 

 evergreen forests and the mixed, deciduous ones is rather gradual, 

 and spread over a comparatively large extent of country ; abrupt 

 changes such as are to be found in the neighbourhood of the high 

 hills of Kwahou and the plains situated to the north and east are 

 not experienced here, where the hills are of insufficient altitude 

 to bring about important differences in the amount of rain pre- 

 cipitated. Nevertheless, even in Western Ashanti the presence of 

 the hills has, to a certain extent, affected the general prevailing 

 type of forest found there, and resulted in a distinctly moister 

 strain of vegetation in localities which would otherwise, on ac- 

 count of their greater distance from the sea and the consequently 

 diminished force of the monsoon currents, be clothed with much 

 drier forests than is actually the case. 



In proceeding from Puliamo to the north towards the Volta 

 River the struggle between the different types to gain the ascend- 

 ancy is very noticeable, and it is just along the borderland, as it 

 were that is, along the belt of country between Puliamo and 

 Braha where the conditions are, so to say, unstable that every 

 little advantage in increased moisture and favourable conditions of 

 soil is eagerly sought for by the mixed deciduous forests, and the 

 struggle is most keen; about here reversions from the mixed deci- 

 duous type to the open, dry, savannah forests are frequent till the 

 country gradually passes into one possessing a small rainfall, 

 when, these conditions being the most favourable for the latter 

 type, the mixed deciduous forests give way to the open, savannah 

 ones, and are henceforth confined to narrow straggling belts along 

 the water-courses and swamps. 



As compared with the mixed, deciduous forests of Central 

 Burma and the Central Provinces of India, the West African type 

 contains on the whole a larger proportion of evergreens, and is 

 more closed, and hence the transition from it to the savannah 

 forests is rather more abrupt than it is in those parts of Asia. 



Between Techerabini and Pamo an extensive patch of grass land 

 was met with for the first time. It was surrounded by mixed 

 deciduous forest, in which far and away the most dominant species 

 is the Duakobin (Afrormosia In.riflora), a large leguminous 

 tree with a very conspicuous red bark that peels off in large 

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