A STUDY OF THE PERIODICITY OF SEED YEARS AID DIRECTIOU OF 

 SEED DISTRIBUTION OF THE MITE PIITE III 

 THE VICIIIITY OF ITHACA, N.Y. 



INTRODUCTION. 



The question of the periodioity of seed years has long been 

 a subject of discussion and some study among foresters. In fact this 

 subject dates back to the very beginning of the science. The primary 

 question to be solved in the culture of trees in the forest, or anjwhere 

 else for that matter, is the problem of reproduction. ?/hen natural 

 reproduction is to be used in the regeneration of the forest it is of 

 the utmost importance to know when the seed will be distributed, in 

 order that the trees may be removed at the proper time. If seed trees are 

 to be left, we must know how far and in what direction the seed will 

 be scattered. .Then artificial reproduction is to be used it is a great 

 advantage to know when and where seed is to be produced in large 

 quantities, so that the expense of collection may be kept at the minimum. 



Up to the present time the contro]3i,ag. factors influencing the 

 periodicity of seed years have not been understood, and about all we 

 know of the subject is that white pines do seed periodically, that a 

 seed year may be expected every three or four years, that a seed year is 

 a local phenomenon and not widespread over the white pine region, and 

 that occasionally we may may have an unusually abundant seed year. 

 These are the facts, but when we are asked to explain then, we. find our 

 present knowledge insufficient to more than hazard a guess. There are 

 so many factors of which we know so little that before any definite 

 conclusions can be reached we must have detailed observations on each 

 one of these. These observations cannot be made by any one person or 

 in anv one place. but must be made at points "well distributed oyer the 



