The Junipers of Lake Valley 



301 



some of these great trunks and making an actual count of the 

 rings. This, however, it was impossible to do in what remained 

 of the vacation. 



Nevertheless it seemed that the data already secured should 

 furnish sufficient basis for a good approximation to the answer 

 desired. Of course no simple scheme of proportionate in- 

 crease as between age and diameter would avail, since age 

 increases regularly by addition of equal increments ; whereas in- 

 crease of diameter is by unequal increments, greatest at a point 

 very early in the life of the tree, and diminishing thereafter to 

 the end. The Glen Alpine tree, for example, could not by any 

 possibility have doubled its diameter of 16 inches in twice its 

 230 years of age. Still less could it have doubled that again to 

 64 inches at 920 years of age. Yet this last diameter — ^by no 

 means extraordinary among mountain junipers — could hardly 

 have been reached short of 1400 or 1500 years! 



Thus there was opened up for these trees a vista of life un- 

 expectedly long, equalling perhaps even that of the giant se- 

 quoias. My thoughts turned at once to a study made many 

 years ago of a magnificent specimen of that race in the Cala- 

 veras Grove, felled while in full vigor of growth at the age of 

 1240 years. By careful count and measurement I secured a 

 complete record of its growth through the four centuries of its 

 youth and the eight centuries and more of its glorious prime. 



Here then was the clue I needed. With those ages and meas- 

 urements^ as coordinates, was plotted the curve of growth ac- 

 tually made by that tree throughout its entire life.** 



It is No. I of the accompanying chart, and it is to serve as a 

 norm of growth with which we may compare, and thus fore- 

 cast, the growth of other long-lived trees of kindred stock and 

 similar figure, growing in the same climate and in the same re- 



H The measurement for each 200-year period was as follows: 

 Years Radius measurement Years Radius measurement 



200 25 inches 800 66 inches 



400 43 " 1000 74 " 



600 56 " 1200 81 " 



The measurements presently to be used in plotting the growth of the junipers are 

 diameter-measurements. This is done merely to facilitate comparison of the different 

 curves by bringing them nearer together, and does not at all affect the conclusions 

 reached concerning the growth of the junipers. Should the diameter of the sequoia 

 be needed, it may, of course, be had by simply doubling these measurements. 



** Since the curve is quite regular, it has been possible to continue it in dotted 

 line, with little risk of error, beyond the actual life-time of the tree to the 3000- 

 year mark. The curves of the junipers have been carried out on the same plan. 



