Jan., 1919] Effects of the Eruption on Vegetation 199 



eruption. The problem which had to be met by th'ese trees 

 was to maintain the extensive system of uninjured roots and 

 branches with almost no leaves until new growth could provide 

 the leaf surface necessary to feed the rest of the plant. The 

 capacity shown by some of the trees of adjusting themselves to 

 such abnormal conditions is remarkable. The most extreme 

 case was found on Soluka Creek where a tall poplar was dead 

 except for a very few twigs in the top. (See page 192.) The 

 bark of this tree, which was 41 inches in girth, was dead along 

 two strips 6 and 4 inches wide, leaving two bands of living bark 

 15 and 16 inches wide and 40 to 50 feet high to be supported by 

 only the handful of leaves at the top. In another case all the 

 bark had dropped off except the narrow strip connecting with 

 the new growth, (see page 198), leaving the tree apparently 

 stripped when viewed from the other side. Since the side of 

 the trees where the bark persisted bore no relation to the posi- 

 tion of the volcano, there is no reason for believing that the rest 

 of the bark was killed in the eruption, this only escaping. It is 

 rather to be supposed that the remainder of the bark died of 

 starvation for lack of ability to put forth leaves. 



TREES STARVING FOR LACK OF LEAVES. 



Along with instances such as the foregoing, where trees have 

 managed to survive with very small leaf areas, are others where 

 they have succumbed through inability to tide over the period 

 intervening before an adequate number of leaves could be 

 grown. On many of the poplars the new twigs, after growing 

 for a little while, blighted and died. On such trees it could be 

 seen that the twigs farthest from the roots were dying first, and 

 many cases were seen where the new twigs close to the ground 

 were continuing to thrive where those higher up had long since 

 withered away. (See page 200). But in others, the whole tree 

 had perished after a futile attempt at renewed growth. This 

 blighting is interpreted as due to the breaking down of the 

 conducting or root systems, which was in turn caused by mal- 

 nutrition from the lack of leaves. In this is found the explana- 

 tion of the survival of saplings where large trees perished, as 

 noted above. The new leaves were able to keep the roots and 

 bark of the sapling alive, but not sufficient to maintain the more 

 extensive roots and tops of the large trees. Thus many trees, 

 comparatively but little injured in the eruption itself, have died 

 subsequently because of inability to make good the destroyed 

 buds. 



