154 WEST AFRICAN FORESTS AND FORESTRY 



Mahogany is represented in this zone as another species which does not 

 attain a greater girth than 10 feet and which is often gnarled and 

 crooked owing to the annual grass fires. A medium sized Cedrela, 

 or hard cigar-box wood, is found in isolated patches in the northern 

 part of the Abeokuta and southern part of the Oyo province. The 

 balsam-copaiba-tree is also very common in this zone in the North 

 Benin, Onitsha and Ogoja provinces. 



The forests of this zone are perhaps the least valuable from the 

 financial point of view, chiefly owing to their geographical position and 

 defective means of trans^Dort, but economically they are of great value to 

 the agricultural community, both for their forest produce as well as their 

 soil -preserving and rainfall -conserving properties. The chief timber areas 

 are situated in the heavy rain forest and mixed deciduous forest areas, 

 though a few have recently been taken up in the mangrove swamps. 



As a minor, though important, development to the main forests 

 are the evergreen hill forests, which find wide development in the 

 northern part of the Jebu-ode, Ondo, Benin, Ogoja and Calabar pro- 

 vinces. On the whole, the species do not vary so much as might be 

 expected, and in many cases it simply means a further distribution 

 of certain evergreen trees beyond their zone of natural development, 

 owing to suitable climatic conditions in these hills. For instance, 

 the red ironwood appears next the mangrove swamp on the bank of 

 the St. Barbara River, again in the evergreen forests near Calabar, 

 and reappears in the hill forests of Oban, much further north. Probably 

 the most typical trees of the hill forests are an unidentified species 

 of gum-copal, as well as several species of Guttifer*. 



The fringing forests are found chiefly on the banks of the rivers in 

 an area which is otherwise covered with the open deciduous or dry- 

 zone formation. Two leguminous trees are most typical of this 

 zone. Stray deciduous or evergreen trees from the other zones are 

 also seen. Such forest is thick with a fair amount of undergrowth, 

 and the trees form a close canopy. The fringes vary from a few 

 yards to half a mile in width. 



A further subsidiary form is found on the summits of the highest 

 mountains, such as the Boji Hills, with their stunted satinwood trees, 

 shrubs and grass. In some places there is yet another minor formation, 

 that of the freshwater swamps. Some typical examples of these are 

 found on the banks of the Calabar, Osse and Owenna Rivers. In 

 most cases only one, or any how only a few species of trees are found, 

 whereas in the major formations several hundred different species appear. 

 The growth in these swamp formations, both mangrove and freshwater, 

 is on the whole not so large as that of the evergreen forest. Again, 

 the evergreen forest does not show such fine development or such 

 height of tree as the mixed deciduous forests, though occasionally 

 the greatest girth of bole is found in the evergreen forests. 



