3 6 4 



FORESTRY AND IRRIGATION 



August 



KUIKUI FOREST, BOTTOM AND SIDES OF DEEP GULCH. 



the most luxuriant undergrowth is 

 always found beneath its small-crowned 

 trees. Indeed, so luxuriant is this un- 

 dergrowth of ie-ie vine and similar 

 climbers, fern growth ranging from a 

 few inches to 30 feet in height, and 

 mosses, that virgin forests of lehua are 

 of ten impenetrable, dark jungles. Thus 

 an ideal condition is created for water 

 conservation. 



The present forest area is about 20 

 per cent of the islands a small frac- 

 tion of what it was a hundred years 

 ago. The destruction of the forests 

 can be traced to three chief causes- 

 clearing for agriculture, stock grazing, 

 and grass encroachment. Cattle were 

 taken to the islands in the eighteenth 

 century, and for years were protected 

 by rigid laws forbidding their slaugh- 

 ter. By 1815 they had so increased in 

 number as to become a menace. The 

 anti-slaughter laws were repealed, and 

 gradually their number has been re- 



duced to the needs of the 

 islands; but their work 

 of destruction had been 

 accomplished. Much of 

 the undergrowth of the 

 native forests was of a 

 succulent character, pe- 

 culiarly agreeable not 

 only to cattle, but also 

 to goats, pigs, and deer. 

 All of these preyed upon 

 the forest, and year by 

 year their trampling and 

 grazing showed more 

 plainly in forest areas 

 wrecked and ruined. The 

 encroaching grasses occu- 

 pied the ground and pre- 

 vented reforestation. In 

 the rainy districts the 

 Hilo grass and in the 

 drier sections Bermuda 

 grass was the offender. 

 Between them they oc- 

 cupy vast stretches of 

 country that were once 

 well forested. 



Clearing for agricult- 

 ural and homestead pur- 

 poses is responsible for 

 very much of forest de- 

 struction. Since the best 

 use to which the lands of the islands 

 can be put is agriculture, no fault can 

 be found with such cutting, provided it 

 is not carried so far as to curtail the 

 water supply on which agriculture itsell 

 depends. The rainfall of the forested 

 portion of the islands is from 50 to 200 

 inches a year, and the native forests 

 furnish the best floor conditions foi 

 storing away this water for future use 

 but when the forest area is made smaller 

 the storage supply of water is lessened, 

 In addition, it appears to be true ir 

 Hawaii that forests influence the amounl 

 of moisture precipitated. Where the 

 mountains, with their cooling atmos 

 phere, do not extend their elevations 

 above 3,000 feet, forests are especiall} 

 needed. The trade winds bring in fog: 

 and mists, and the forests perform th( 

 excellent function of changing these t( 

 water and leading it to the ground foi 

 storage. Thus, continued forest cutting 

 means danger both to the amount o 



