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ests, IS a tree of pronounced intolerance, that is, it is not able to 

 grow in shade. This is indicated by the thin, upright, scraggly 

 crowns of this tree and by the fact that one never sees a healthy 

 ohia lehua growing in the shade of other trees. For its best de- 

 velopment the tree demands full sunlight from the time the seed 

 germinates until it reaches maturity. 



The ohia lehua, moreover, bears in enormous (juantities 

 minute seeds which are very light and are carried to great dis- 

 tances by the wind. On a new lava flow, where moisture condi- 

 tions are favorable, this seed lodges in the woolly scales of ferns, 

 which, owing to their fine spores, are first to establish themselves 

 on such situations. Later on, when the stand of ohia lehua has 

 established itself and succeeded the smaller ferns, a new condi- 

 tion arises. The presence of the trees produces shade which 

 fosters moisture. Organic material from the trees in the form of 

 leaves and dead branches drop to the ground and develop humus 

 which, in combination with the disintegrated lava, broken up by 

 the roots of the trees, produces a soil in which shade enduring 

 tree ferns then appear. 



When the older ohia trees reach maturity they must necessarily 

 reproduce themselves from seed and in order to do this in the 

 presence of such an undergrowth, they have adopted the re- 

 markable habit of using the tree ferns, other plant growth, and 

 fallen trees, in fact, any place where the seed can be exposed to 

 the sunlight, as a germinating bed. Wherever such places of 

 lodgment for the seed present light conditions which are ade- 

 quate for germination, we find the young plant sending its roots 

 -down the host tree to the ground where they then perform the 

 normal functions of support and nutrition. These roots gradu- 

 ally become larger and larger until the tree is entirely independent 

 oi its nurse and in the process of time the host plant finally de- 

 cays and the tree is left standing on these stilt-like roots, which 

 to all appearances are simply divisions of the trunk. Thus the 

 tree ferns and other undergrowth act in cooperation with the 

 upper story of trees by protecting the shallow-rooted system 

 of the tree and serving as a germinating bed. It is only in this 

 complicated manner that the ohia lehua, a tree of such pronounc- 

 ed intolerance, can reproduce itself in the wet, dark forest 

 generation after generation. 



The seed of this tree is most difficult to germinate artificially 

 and the seedlings are of slow growth and not readily handled in 

 the nursery. For these reasons, it is not a satisfactory species to 

 use in artificial reforestation. Moreover, the forester must rely 

 as far as possible for the sake of economy on the natural repro- 

 duction of the forest. 



') For the continuance and perpetuation of the ohia forest we 

 must, therefore, depend largely upon natural methods, methods 

 Which are well-nigh impossible to replace by artificial means, but 

 in order to perpetuate the natural methods we must give every 

 assistance by aft'ordiiig the forest absolute protection. 



