GOLD COAST REPORT ON FORESTS. 171 



reduced by evaporation ; hence, for their successful growth fre- 

 quent, if even weak, showers of rain are necessary during the 

 vegetative period, viz., the spring and early summer (March to 

 May), and a moderate degree of heat during the same period. 

 They are indifferent to the degree of moisture in the sub-soil 

 or, during their resting periods, the winter months (November 

 to February), to drought and exposure to dry winds. On account 

 of their lower stature and the proximity to the surface of the 

 ground of their vegetative organs, they are subjected to moister 

 conditions of the atmosphere and do not suffer to anything like 

 the same extent from dry winds as plants composing the woodland 

 formations do. The most favourable conditions for the latter 

 are a warm vegetative season, continuously moist sub-soil, and 

 damp calm air. 



Of great importance to grassland is, in the tropics, the forma- 

 tion of heavy dew during the early periods of vegetative activity 

 and the indifference of the grasses to the fierce annual fires that 

 sweep over the drier portions of West Africa during the winter 

 season. 



These two great formations of Grassland and Woodland are 

 continually hostile to each other, and in the struggle that often 

 takes place between them, the victory in any locality rests with 

 the formation that is best adapted to the climatic and edaphic 

 conditions prevailing there. Under the most favourable con- 

 ditions for woodland, we have the hygrophilous trees; with less 

 favourable conditions the tropophilous and xerophilous trees ; 

 and last of all, xerophilous scrub, which corresponds to the worst 

 environment. The corresponding conditions for the existence of 

 grassland are associated with the presence of pure savannah, 

 savannah-forest, and small isolated patches of grass-land within 

 districts with hygrophilous and tropophilous wood-laud climates. 



With reference to the attitude displayed by these two' forma- 

 tions towards one another, it is important to note that in accord- 

 ance with the climates now prevailing, the domain of each ha& 

 l>econie more or less defined and limited, but that very small 

 changes of climate will suffice to renew the contest, and, above 

 'all,, that in districts where the climate is such as not to 

 decidedly favour one or the other, the action of man is sufficient 

 to start the struggle. Moreover, though in a decided woodland 

 climate, forest will generally succeed to destroyed forest growth, 

 yet the new forest is almost invariably of a more xerophiloue 

 (dry) character. And if the process of destruction is repeated 

 at pretty frequent intervals, it is followed first by savannah 

 forest and then by pure savannahs. 



Edaphic Formations. 



These are dependent on the character of the soil, and for the 

 purpose of this report may be divided into the following types :- 



(a.) Fringing Forests. They are similar in character to a 

 hygrophilous forest, but are dependent on a telluric supply of 

 moisture, and are hence confined to the vicinity of the beds of 

 streams and similar collections of water. 



