PERIODICAL LITERATURE 1003 



In the Katmai district in Alaska a study has been made by Griggs 

 not only on the effect of the great eruption of Mount Katmai on plant 

 life but on revegetation as well. The eruption which occurred in 1914 

 covered the entire region with a deep layer of volcanic ash, which in 

 places left the country absolutely without living plant life. The paper 

 under review is a record of the first stages in revegetation in the valley 

 of the Katmai River, 



It was ascertained that at Kodiak and at other localities with broken 

 and abrupt topography the deep covering of ash was rapidly removed 

 by erosion and the first vegetation to appear after the eruption was 

 chiefly the old perennials which had survived and come up through the 

 remaining ash cover. In the broad, flat valleys such as those along the 

 Katmai River, the ash covering was less rapidly removed by erosion, 

 the antecedent vegetation was more completely destroyed and the de- 

 posit of volcanic ash was deeper. Here the only survivals were certain 

 woody plants which protruded through the layer of ash and perennial 

 herbage which came up in places more or less completely cleared of ash. 

 In the main, poplars, birches and alders have not survived sufficiently 

 to be of consequence in revegetation. Several species of willow, how- 

 ever, have completely recovered and are already becoming an important 

 factor in revegetation. The perennial herbage surviving the eruption 

 is of little importance in the revegetation of the Katmai Valley. 



Throughout almost all of the valley revegetation is chiefly dependent 

 upon seedlings which start from seeds from adjacent regions. Due to 

 the rapid removal of the ash from the adjacent mountain slopes, there 

 were adequate survivals of woody plants and herbaceous perennials on 

 these slopes to provide ample seed to restock Katmai Valley, as most of 

 the species have seed adapted for wind dissemination. 



Although seedlings were beginning to start on the deep covering of 

 ash in 1915, they were few and scattered. The next year a definite 

 change was noticeable and the beginnings of a new vegetation was 

 apparent. Lupines were the most effective pioneers, although many 

 additional annuals and perennials were appearing on the moister sites. 



Examination of the soil shows it extremely poor in micro-organisms 

 and nitrogen. 



Four species of willow constitute the first woody vegetation to start 

 from seeds. In some localities the ground was well covered with the 

 young seedlings two years after the eruption. Present indications ap- 

 pear to show that the pioneer growth over considerable areas will be a 

 willow thicket. 



