722 WHITPOBD. 



Dipterocarpus grandiftorus and Dipterocarpus vemicifluw in shape of 



bole, habits of growth and wood as well as fruit, and Dipterocarpus 

 tuberculatus occur scattered all through the forest and probably have as 

 Large a yield as there is of all other species combined. They are nol 

 logged, however, except in the more accessible places. I also noted a 

 Parashorea and a Shorea in the forest." Foxworthy 1 ' states that it' all 

 woods other than the dipterocarps were excluded from the markets of 

 the tropical East, the markets woidd hardly feel the difference. 



So much for the Asiatic tropics. Will the tropical regions of Africa 

 and South America show similar quantities of general construction 

 timbers in their virgin forest ? So far as I know, economic ami scientific 

 explorations have been mainly attempts, from the viewpoint of the 

 lumberman, to find valuable hardwoods of the mahogany grade or hard 



durable timbers. The forests as a whole have not been sized up from the 

 standpoint of the forester with a \ie\v to the utilization of all the species. 

 From the results of the investigations given above, made in the Philip- 

 pines, it is probable that the virgin forests of South America and Africa 

 will show that a greater part of their bulk will consist of woods suitable 

 for general construction purposes of certain classes, which can. with the 

 introduction of modern methods of logging and milling and with improved 

 economic conditions that are sure to come with the development of the 

 tropics, be placed in the markets of the temperate regions at a cost that 

 will enable them to compete with woods of similar qualities found in 

 virgin forests in temperate regions or grown there as successive crops. 



In the United States an inventory of the natural resources is being 

 made with a view to conserving them. An attempt is being made to 

 extend this conservation inventory to other parts of the world. So far 

 as the forest resources of the world are concerned 1 believe that there is no 

 problem that will ultimately yield greater scientific and economic results 

 than an inventory of the forest resources of the tropical world. This will 

 include a mapping of tin 1 forested areas, a rough estimate of the standing 

 timber, and a brief description of the areas as regards their lumbering 

 possibilities and the classes of timber found. 



Mention was made above (page 101) that inclement should be con- 

 sidered as a factor in an estimation of success in forest vegetation. In 

 some forest trees id' the Philippines rings of growth occur. In others 

 these are lacking or obscure. If is not known whether these rings are 

 annual or only seasonal. On this account no estimate can be made of 

 the annual inclement from rings of growth. Actual measurement of rate 

 of tree growth in the tropics is not extensive enough to be of general 

 application. If is believed, however, that the rate of growth in the 

 tropics is much greater than in temperate zones, that generally speaking 

 the soft wood forest trees will reach maturity in one-half to two-thirds 



13 Foxworthy, F. VY. ln<lo-Mnlay;m Woods. This Journal 4 (1909) Botany 606. 



