134 GEOLOGICAL SURVEY OF NEW JERSEY. 



Table 22. 



Average Rate of Growth in Diameter and Heighth of 

 Seventeen White Cedars. 



Age. Diameter. Height. 



Years. Inches. Feel. 



20 2.2 II 



30 3-7 21 



40 5.4 32 



5° 7-1 40.5 



60 8.6 48 



70 . . . . , . . 9-8 54-5 



80 10.9 .. . . 60 



The Cedar appears, from this table, to reqiiire on an average 

 sixt)' years to reach a height of fifty feet and eighty years to 

 reach sixty. It is interesting to note that when the forest is 

 thinned the trees grow more rapidly in diameter than when they 

 remain in crowded stands. At Marigold swamp seven stumps 

 were measured of trees which had stood for some years on the 

 'edge of a clearing. These trees were growing at the rate of 2.2 

 inches in diameter in ten years, whereas four trees measured 

 within the same stand showed an average rate of growth of 

 about 1.05 inches in ten years, or a little less than half 



YIELD. 



There are few trees, if any, which grow in as dense masses as 

 White Cedar. In order to show the number of trees per acre 

 and the amount of wood at different ages, eight sample plots 

 were measured and the trees counted. These valuation surveys 

 are summarized below. At twenty years of age there were over 

 10,000 trees per acre, at forty years about 3,500, and at eighty 

 years in one case still over 1,000. Special attention is directed 

 to Plots Nos. 51 and 52. These plots were within a few hundred 

 yards of each other and of about the same age and height. In 

 the first case, however, there are nearly two hundred trees less 

 and a correspondingly larger diameter. While the number of 

 cubic feet per acre is nearly the same the number of board feet 

 is very much larger in the first plot, although there is a smaller 



