8 The Ohio Journal of Science [Vol. XIX, No. 1, 



COMPARISONS WITH REVEGETATION IN OTHER VOLCANIC 



DISTRICTS. 



But, although the country around Kodiak presents only a 

 subordinate aspect of the problem of re vegetation, it is, ' as 

 may be seen below, more similar to most of the other volcanic 

 districts whose revegetation has been studied, than the country 

 nearer the volcano. It seems appropriate, therefore, to digress 

 at this point for a comparison of the Katmai district with other 

 volcanic regions. 



There is a very natural tendency on the part of many to 

 group the revegetation of all volcanic terrains under a single 

 generalization. Considering how remote volcanic phenomena 

 are from the experience of most botanists, this is quite excusable. 

 But when one's attention is called to the fact that volcanic 

 ejecta not only vary in physical condition all the way from 

 compact glassy rock to fine sand, but also have all the varieties 

 of chemical composition shown by igneous rocks from basic 

 to acid, he sees at once that the establishment of plant life on 

 different volcanic terrains may be as diverse as on soils derived 

 from different varieties of sedimentary rocks. The problems 

 encountered by Forbes^ and MacCaughey,^ for example, in 

 studying plant invasion on Hawaian lava flows have little 

 in common with those that confront us in the Katmai district. 



Moreover, as our knowledge of the phenomena of the 

 eruption increases, and the affected country is better explored, 

 it becomes more and more evident that the eruption of Katmai 

 stands in a class by itself, offering opportunities for the study 

 of revegetation quite without parallel since the development 

 of modern botany, before which, of course, no such studies 

 could have been made. 



KRAK.\TOA. 



The eruption of Krakatoa, for example, will occur to 

 botanists and geologists alike as the greatest of volcanic explo- 

 sions. Yet the total area on which the studies of revegetation 

 were made, the island of Krakatoa, was only about five square 

 miles in extent — so small that it could almost be dropped 



•* Forbes, C. N. Prelim. Obs. Concerning the Plant Invasion on Some of the 

 Lava Flows of Mauna Loa, Hawaii, Bishop Mus. Honolulu. Occ. Pap. 5: 15-23. 1912 



^ MacCaughey, Vaughan. Vegetation of Hawaiian Lava Flows. Bot. Gaz. 64: 

 386-420. 1917. 



