18 FORESTS OF THE HAWAIIAK ISLAI^DS. 



accessible parts. The more inaccessible and impenetrable parts 

 remained intact till later, for cattle could only work around the edges 

 of these, entering a little further eacli 3^ear; but now in mam' instances 

 they have gone through the entire forest. 



The character of the Hawaiian forest makes it peculiarl}^ susceptible 

 to injur}' b}- cattle. The tender, succulent undergrowth is easily 

 trampled down, and much of it, especially ie-ie, banana, and some of 

 the ferns, is excellent food for stock. Yet this undergrowth is a vital 

 part of the forest; without it the ground dries quickly and the shallow- 

 rooted trees soon die. 



Goats were introduced into the islands many 3'ears ago, and have 

 been particularh' active agents of destruction. The}- are now found 

 on all the important islands. Their work, though localized, is more 

 thoroughly destructive than the work of cattle. Ridges where they 

 rendezvous ma}^ be distinguished for miles by their utter barrenness 

 and eroded condition. Goats are especiallv hard on precipitous slopes. 

 The}' Avill lay completely bare places so steep as to be shunned alto- 

 gether by cattle. 



Wild pigs, the progeny of stock introduced years ago, have done 

 some damage on all the islands. They tear up the tree fern, seeking 

 its roots for food. 



Deer brought to jNIolokai in the early sixties have taken their share 

 in the destructive work. Several years ago they had increased to 

 such immense numbers as to damage the forest considerably by brows- 

 ing on and trampling down the undergrowth and rubbing the bark 

 from the young trees. 



•INSECTS. 



Following the attack of stock have come other agents of destruction. 

 Injurious insects have at times appeared in numbers sufficient to 

 deaden and even eventually to kill the timber over thousands of acres 

 at a time. Ohia-ai, which grows in dense stands in low, wet valleys, 

 was so completely defoliated a few years ago as to be almost ruined. 

 Koa is periodically defoliated. It has upward of a dozen insect 

 enemies which threaten its utter extinction. Borers are even more 

 common than leaf -eating insects. In nearly all cases insects have been 

 most severe where the forest was enervated by grazing. Portions of 

 the ungrazed forest have at times been destroyed by insects, but only 

 in consequence of the headway gained on near-by areas which have 

 suffered by grazing. 



GRASSES. 



Many thousand acres of forest land despoiled by cattle have been 

 overrun by rank-growing grasses, which have rendered conditions 

 prohibitive of forest reproduction. Probably the worst of these is 

 Hilo grass {Pasjyaliim conjugatum), which grows 2 to 3 feet high in 



