HAWAIIAN TREE FERN AS A SOURCE OF STARCH 



5 



established at different altitudes for the purpose of determining the 

 feasibility of planting the tree fern for starch production. These 

 experiments were carried on at the following places: 



(1) Volcano plat (3,500 feet elevation) on the McKenzie ranch, at 

 29 Miles, Volcano Koad. This plat is adjacent to the forest re- 

 serve on windward Hawaii. It is used as a pasture and contains a 

 scattered growth of tree ferns. The experiment was made here to de- 

 termine whether the tree fern could be successfully planted on areas 

 that had been denuded of their original growth and on which there 

 was no shade. 



(2) Glen wood plat (2,000 feet elevation), located 2 miles above 

 Glenwood on the Volcano Eoad. This plat was selected because it is 

 in the midst of an excellent tree-fern growth and is easv of access. 

 (PL III, fig. 1.) 



(3) Mill plat (2,200 feet elevation), located 4 miles north of the 

 Volcano Eoad at 18 Miles. This plat is in an area now being cut 

 over for starch production. It represents ideal conditions as to 

 shade, soil, and the like under which the tree fern would be planted. 



The plantings included crowns, and large, small, and medium 

 sized lateral shoots of each of the several species. Comparative 

 plantings were made, to determine the effect on growth of varying 

 the length of the starch core attached to the cuttings, drying the 

 cut surfaces before planting, planting at different depths, in different 

 kinds of soil, and at various altitudes. Since this work was dis- 

 continued before the effect of these various factors on the growth 

 of the tree fern was determined, the general conclusions of the 

 experiment only are given. 



Under true forest conditions, such as existed at the Mill plat, all 

 crowns and lateral shoots were successfully propagated, regardless 

 of variety, size, method of planting, or length of attached starch core 

 (PI. Ill, fig. 2). Fully 70 per cent of the small, undeveloped shoots, 

 which had been detached from the starch core of the parent tree, 

 grew when planted. 



The plantings made in the open pasture on the Volcano plat 

 started vigorous growth during the cool, moist winter months, but 

 died during the dry, hot summer months. Other plantings, made in 

 a shaded area closely adjacent, lived and gave results similar to 

 those obtained at the Mill plat. 



In brief, it is concluded that, under true forest conditions, an 

 average of three successful plantings or sets can be made from each 

 felled tree fern ; and that the starch core of the parent tree need not 

 be attached to the plantings or sets. It seems evident, therefore, that 

 a cut-over area could be successfully replanted without interference 

 with starch production, and that the density of growth could be 

 gradually increased to a maximum. 



METHODS OF GROWTH 



In order to determine how fast the tree-fern trunk grows, it was 

 necessary to learn the nature and method of its growth. For this 

 purpose a study was made of the lateral growth of the trunk, the 

 vertical growth within the trunk, growth at the base of the trunk, 

 and growth at the top of the trunk. 



