RAINFALL A FACTOR OF TREE .INCREMENT. 



Condensed from an Article by FRA^fefs Davis, C. E. 



The investigations of Bohmerle, Cieslar, and those of other 

 European students of the subject, appear to show a correlation 

 between tree increment and the amount of annual rainfall. (See 

 Forestry Quarterly, Vol. V, 1907). 



In order to determine whether similar responses obtained in the 

 United States, specimens were obtained from Michigan, Vermont, 

 New Hampshire, Massachusetts, New Jersey, New York and 

 Long Island, N. Y. These were studied, the rings were measured 

 and plotted, the monthly rainfall was tabulated. The results 

 given in the following pages were found to exist between the 

 meterological conditions and the wood increment.* 



Samples were obtained from Shoreham, Long Island, located on 

 the north shore of the Island about thirteen miles east of Port 

 Jefiferson and lies immediately on the Sound. The land at Shore- 

 ham is high and the underlying watertable is about 100 feet below 

 the surface of the ground. The soil is the usual sandy soil to be 

 found everywhere on Long Island, but in this case the top-soil and 

 sub-soil is far from being rich. 



The specimens are all taken from the land of the Suffolk County 

 Land Company's property, and the trees were growing under 

 natural forest conditions, about one-half mile from the Sound on 

 the highland. They were good healthy trees, cut during the 

 winter of 1908- 1909. 



♦The original article was accompanied by 15 diagrams showing graphi- 

 cally the relationships. We have space only for reproduction of one 

 sample. 



