THE ACTION OF SALTON SEA WATER ON VEGETABLE TISSUES. 



By MbiiVin a. Bbannon. 



The recession of the waters of the Sal ton Sea began in February 1907, and as the level 

 fell from 42 to 54 inches annually, each year laid bare wide strips of beach which had been 

 occupied by a halophytic and xerophytic vegetation previous to the formation of the lake. 

 It is probable that many representatives of the species listed by Mr. Parish in a separate 

 section of this volume were covered by the water during the years 1904 to 1907. 



But examination of the emersed zones uncovered by the recession of the lake failed 

 to disclose the remains of any annuals or herbaceous plants, and their disappearance may 

 be attributed to facts revealed by the investigations reported in this paper. Remains of 

 the woody plants were fairly abundant, however, and in the autumn of 1911 Dr. D. T. 

 MacDougal forwarded portions of stems and branches of Prosopis glandulosa and Larrea 

 Iridenlata to the Botanical Laboratory of the University of Chicago, where a study of the 

 changes which this material had undergone was made. The material included specimens 

 which had been submerged in 1906 and had emerged in 1907, 1908, 1909, 1910, and 1911. 

 It was all thoroughly desiccated by the time it came to hand. The specimens were very 

 hard, except those which had been submerged but a year, and all were destitute of cortex. 

 (12 s., 13, and 14.) Material which had been submerged for more than a year had under- 

 gone the full extent of the alterations described below. 



Efforts were made to secure Uterature relating to the subject under investigation, but 

 extensive inquiries in America and Europe were fruitless. While a very large niunber of 

 examinations have been made of the action of saline and brackish water on living plants, 

 reported in hundreds of papers, and while many tests of the preservative effects of various 

 salts on different woods have been made, yet the action of saUne waters or fresh waters 

 on the tissues of plants killed by flooding and remaining immersed in situ for long inter- 

 vals of time has been little investigated. This omission seems strange when we consider 

 the intimate relations of the physical chemistry of such problems and the large economic 

 questions involved in the disposal of sewage, decomposition of manure and humus, and the 

 carbonization processes associated with the coal formations. 



The appreciation of the problem reported in this paper will be increased by knowledge 

 of the geography and topography of the Salton Sea region. Detailed reports respecting 

 the formation of the Colorado district and the low-lying basin known as the Salton Sea 

 may be had by consulting references (1)^ and (2),^ and the sections of this volume on the 

 geography and surface geology of the Salton Sink and the Cahuilla Basin. 



A consideration of the physical and biological factors operating in the Salton Sea 

 waters during the years that these woods were immersed, are illuminating in connection 

 with experiments which were carried forward in the Botanical Laboratories of the Uni- 

 versity of Chicago while endeavoring to discover the processes which caused the changes 

 in the woody tissues. 



The chemical analyses of the Salton Sea waters during the years 1907-11 are instruc- 

 tive. The reports set forth in table 24 were secured by the chemists. Dr. W. H. Ross and 

 Prof. R. H. Forbes. 



> D. T. MacDougal: The Desert Basins of the Colorado Delta, Bull. Am. Geog. Soc, Dec. 1907. 

 'Newell: Smithsonian Report, pp. 331-345, 1907. 



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