EFFECT OF CUTTING UPON [REPRODUCTION. 



Table 10. — Diameter growth of western yellow pine in two forest types. 



23 





Diameter breast 





Diameter breast 



Age. 



high outside bark. 



Age. 



high outside bark. 













Compos- 

 ite type. 



Western 

 yellow- 

 pine type. 





Compos- 

 ite type. 



Western 

 yellow- 

 pine type. 



Years. 



Inches. 



Inches. 



Years. 



Inches. 



Inches. 



10 



0.6 



0.9 



190 



23.6 



20.4 



20 



1.3 



2.0 



200 



24.7 



21.1 



30 



2.2 



3.3 



210 



25.8 



21.7 



40 



3.4 



' 4.6 



220 



26.9 



22.4 



50 



4.6 



6.0 



230 



27.9 



23.0 



60 



6.0 



7.4 



240 



28.9 



23.6 



70 



7.5 



8.6 



250 



29.8 



24.2 



80 



9.0 



9.9 



260 



30.6 



24.7 



90 



10.5 



11.1 



270 



31.4 



25.2 



100 



12.0 



12.2 



280 



32.2 



25.7 



110 



13.4 



13.4 



290 



32.9 



26.1 



120 



14.8 



14.4 



300 



33.5 



26.6 



130 



16.2 



15.4 



310 



34.1 



27.0 



140 



17.5 



16.3 



320 



34.7 



27.4 



150 



18.8 



17.2 



330 



35.2 



27.7 



160 



20.0 



18.1 



340 



35.7 



28.0 



170 



21.2 



18.9 



350 



36.2 



28.4 



180 



22.4 



19.7 



360 



36.6 



28.7 



EFFECT OF CUTTING UPON REPRODUCTION. 



To determine the rate of establishment and loss of seedlings of the 

 different species during the early stages of development, and the 

 controlling factors, a reproduction study was begun in the fall of 

 1910 on the cutting plots established within the composite type. 

 Three reproduction plots ranging in area from 5,000 to 7,500 square 

 feet were laid off, each within a cutting plot of from 1 to 2 acres 

 in extent, cut under a specified system, and representative of a 

 certain site or subtype of considerable area. 



Permanent scribed stakes were set at the corners of each plot; 

 smaller ones were placed along each end at intervals of 5 feet. By 

 stretching steel tapes between corresponding stakes at opposite ends 

 of the plot, and using strips of boards for cross lines, it was possible 

 to do the counting and recording by plots 5 feet square. The kind, 

 number, and age of all small reproduction was noted. In the case 

 of larger seedlings and saplings, where the age could not be ascer- 

 tained, the species was noted, and the height up to 10 feet recorded 

 by foot classes. The location of all trees and stumps on or immedi- 

 ately adjacent to the plots, together with the size, species, etc., were 

 likewise charted. 



In order to determine the light requirements of the different 

 species, several stations, each representing a different light intensity, 

 were selected on each plot, and a series of light readings was taken 

 during the clear weather in September, 1910, at every hour from 8 

 a. m. to 5 p. m. ; for a period of three days. 



To determine whether or not a brush covering lessens the damage 

 done by frost, both in the actual freezing of the tissues and in heaving 



