Rainfall a Factor of Tree Increment. 223 



Both of these trees responded to the rainfall as indicated by 

 the underlined figures which show low increments in the drought 

 years. 



A number of other specimens were obtained at Shoreham, they 

 were taken from a natural forest growing under normal con- 

 ditions, with the watertable 100 feet below the ground. 



The Shoreham sections are unusually interesting and show vari- 

 ous kinds of trees reacting to the meteorological changes. 



The great drought year 1908 invariably shows a reaction with 

 the exception of 8 S., which taking an average of nine diameter 

 measurements shows a slight increase over the year 1907, the 

 amount being less than 1/16 of an inch. The measurements taken 

 for this tree for the years 1907 and 1908 are as follows : 



1908, 33 33 2.25 3331-5 



1907. 3 3-5 3 3 1-75 2 2 2 2.5 



showing that the tree practically held its own, probably due to its 

 sheltered position in the woods, and the fact that it was protected 

 from the north wind and open to receive the warmth of the sun's 

 rays. Exceptions are naturally expected. On the whole, the 

 samples prove that at least on Long Island rain exerts a certain 

 influence over tree increment. 



Samples were obtained from the N. Y, Botanical Gardens and 

 here again it is noticeable how the rain influenced the formation 

 of the annual rings, how the location of the tree, its exposure to 

 the sun's heat, the light, its protection from cold winds, all affect 



