316 



FORESTRY AND IRRIGATION 



July 



introduction of strict protective meas- 

 ures has resulted in less friction than 

 when the question has been attacked 

 abruptly. 



The question of influence of forests 

 in conserving the water supply, while 

 being an important one, cannot be so 

 grave here as is experienced in coun- 

 tries whose climate allows the accumu- 

 lation of a thick humus to cover the 

 forest floor, and where rainfall is less 

 abundant. 



The warm climate and continued 

 moisture of these islands promote 

 rapid decomposition of the forest lit- 

 ter, so that the small quantities that 



damp soil, even though practically 

 void of humus, collect and conserve 

 immense quantities of water during 

 the rainy seasons, gradually releasing 

 it during the succeeding dry months. 



Nowhere has the writer seen the ef- 

 fect of deforestation so pronounced as 

 in the southern portion of Rizal prov- 

 ince. Here the watersheds which were 

 formerly forested have long been ex- 

 posed and are now mixed parang and 

 cogonales. The rolling aspect of the 

 country is extremely dry during three 

 or four months of the year, at which 

 season but few streams find their way 

 to the lake. Certain of the ravines 



Protective Value ot Crown Cover Against Heavy Tropical Rains. 



are allowed to accumulate conserve an 

 insignificant quantity of water. 



The question of erosion is an im- 

 portant one, not only regarding its in- 

 fluence on future forest growth, but 

 from its bearing on agricultural soils 

 of the low lands. Beyond the consid- 

 erable benefit which the dense cover 

 of tropical forest affords, by dissi- 

 pating the force of heavy seasonal 

 rains, wherever such may occur, and 

 by retarding subsequent rapid evapo- 

 ration, factors largely determining or 

 regulating the "flow-off" are topogra- 

 phical, and the character of the soil 

 of the broad forested slopes, with their 



farther inland are still wooded and 

 here water may be found throughout 

 the year, but during their course 

 through the open country the smaller 

 streams are raduallv absorbed and 

 only the larger ones find their way to 

 the lake. 



One would naturally expect that the 

 grass-covered areas would be of great 

 value in retarding erosion, and such 

 would be the case were they not burn- 

 ed over during the dry months just 

 prior to the rainy season, which ex- 

 poses those areas to the beating rains. 



The question of forest protection is 

 one that stands among the foremost 



