22 SYLVICULTURE IN THE TROPICS 



Senegal (Fig. 4). The Balsamodendron and Bosivellia 

 are also found in the next zone, but in dry rocky 

 situations. 



The dry zone may be said to be the home of the 

 " savannah forests." These forests are generally some- 

 what open in character, with the spaces not only 

 between but under the trees filled with various grasses 

 and other herbaceous plants and shrubs. It is in this 

 zone that large trees begin to be met with, e.g. various 

 Acacias, the Baobab or Monkey-bread tree (Adansonia 

 digitata), the Sausage tree (Kigelia), African Mahogany 

 (Khaya spp.), etc. These forests are sometimes thorny 

 and may be pure, such as those of Acacia planifrons 

 in S. India, and near Mannar in Ceylon, or, more com- 

 monly, they are composed of a variety of species, the 

 majority of which are leafless during the driest months 

 of the year. 



Other local factors, such as the constant comparative 

 humidity of the air, as in the case of forests growing 

 not far from the sea, may change the character of these 

 forests. In Ceylon, for example, the forests growing 

 within this zone are to a large extent evergreen, although 

 certain dry-weather leaf-shedders are found scattered 

 through them. From an economic point of view these 

 forests are capable of yielding major produce, such as 

 timber and firewood, and several species yield minor 

 produce in the shape of tanning material, fibres, gums 

 and gum-resin, catechu, and even in some cases (e.g. 

 Landolphia owariensis) rubber. 



The moist zone is an important one with respect 

 to forests. These are generally composed of deciduous 

 trees varying from open savannah-forest to dense forests, 

 such as those formed by Sal (Shorea robusta). In India 

 and Ceylon it is the typical forest-zone and contains 

 most of the valuable timber trees such as Teak (Tectona 

 grandis), Sal (Sho? t ea robusta), Satinwood (ChJoroxylon 

 Swietenia), Ebony (Diospyros Ebenum), Trincomalie- 

 wood ( Berrya Ammonilla), etc. Near the coasts where 

 the atmosphere is more charged with humidity a larger 



