722 WlllTFOKl). 



DipUrotarpus yrandifionis and Piplrroair/ms vcriikifiaus in shape of 

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

 tuhcrculains occur scattered all through the forest and probably have as 

 large a yield as there is of all other species combined. They are not 

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

 Parushorm and a Shorea in the forest." Foxworthy" states that if all 

 woods other than the dipterocarps were excluded from the markets of 

 tlie tropical East, the markets would hardly feel the difference. 



80 nmch 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 and scientific 

 explorations have been mainly attempts, from the viewpoint of the 

 lumberman, to lind valuable hardwoods of the maliogany grade or hard 

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

 standpoint of the forester with a view 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 

 foi" 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 tlie markets of the temperate regions at a cost that 

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

 virgin forests in temperate regions or grow^n 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 inventoiy to other parts of the world. So far 

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

 problem that will ultimately yield greater scientific and economic results 

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

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

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

 possibilities and the classes of timber found. 



Mention was made above (page 701) that increment sliould be con- 

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

 some forest trees of the Philippines rings of gi-owth occur. In others 

 tiiese are lacking or obscure. It is not known whether these rings are 

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

 the annual increment from rings of groAvth. Actual measurement of rate 

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

 application. It is believed, however, that tlie 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 



'^ Foxworthy, F. W. Indo-.Malayan Woods. This Journal 4 (1909) Botany oOC^. 



