Nov., 1918] Recovery of Vegetation at Kodiak 17 



the composition of pulverized granite. If one will compare 

 the soils derived from the weathering of granite with those 

 formed from basalt, he will see how inapt is the comparison 

 of volcanic ash with such soils, for granite forms a notoriously 

 poor soil. 



More direct evidence than the reasoning from the analysis, 

 however, may be had from the results of attempts in laboratory 

 and field to grow plants in the ash, which will be reported in a 

 special paper. In the present connection it is sufficient to say 

 that when such a plant as wheat is grown in the ash, it starts 

 well and grows so long as the supply of nutriment stored in 

 the seed holds out, but when this is exhausted the plant soon 

 starves to death. While it is perfectly true, therefore, as has 

 been stated elsewhere, that the ash has improved the pastures 

 at Kodiak, this is not attributed to any chemical effect, but 

 is to be accounted for largely by its action as a mulch, which, 

 by smothering the smaller herbs, provided improved conditions 

 for the stronger plants which pushed up through it ; and second, 

 by the improvement in the physical condition of the soil when 

 mixed with the ash, for the old soil was inclined to be heavy, 

 mucky, and poorly drained. 



CLIMATE OF KODIAK REMARKABLY MILD. 



It will also be advisable before taking up the botanical 

 features of the recovery, to discuss the climate of the district, 

 for this has an important bearing on the course of revegetation, 

 and like the chemical composition of the ash is subject to 

 much misconception by those who have not given it especial 

 attention. The Government Experiment Station at Kodiak 

 has for a number of years kept records of temperature and 

 precipitation w^hich are summarized herewith (Tables I and II). 

 These records were supplemented during the field season of 1916 

 by observations of some features of more especial importance 

 to the growth of plants. The instruments used were a Friez 

 Hygrothermograph, a battery of non-absorbing porous cup 

 atmometers placed in various habitats, a rain gauge, and a 

 barograph to assist in forecasting the weather, a very important 

 item in work involving so much use of boats in the open. The 

 continuity of the records was made possible by the assistance 

 of my wife, who, as the silent partner in all the investigations, has 

 contributed greatly to whatever merit the work may possess. 



