PRi:LIMIXARV report of EXPKRIMKXTS in PENNSYLVANIA 307 



1. Most conifers planted upon clear-cut hardwood areas, particularly where 

 chestnut predominates, will not develop into satisfactory stands unless assisted 

 by removing the interfering sprout growth. 



2. The best time to make the first assistance cutting is about the third to fifth 

 years after the establishment of the plantation. 



3. A plantation is suppressed beyond satisfactory recovery at about the tenth 

 year, if not assisted. 



4. A second assistance is usually required and should be carried out about the 

 eighth to twelfth year of the plantation. As a rule, the second assistance cutting 

 need not be so complete as the first. Limiting the cutting to the growth which 

 immediately surrounds the desirable trees may suffice. After the second assist- 

 ance cutting the plantation will usually be bej-ond the damaging influence of the 

 surrounding hardwood growth. 



5. Incomplete cutting of sprouts — that is, leaving a few dominant sprouts of 

 each stool — is silviculturally and economically recommendable. 



FOREST CONVERSION EXPERIMENT II 



In the spring of 1912 a companion experimental planting was estab- 

 lished on the Caledonia State Forest for the purpose of ascertaining 

 the best method of replacing with valuable timber trees the inferior 

 scrub-oak growth, which occupies extensive areas in certain parts of* 

 the State. The area selected was covered with a dense growth of scrub 

 oak, overtopped by a scattered growth of aspen and a few^ pitch pines 

 and oaks. Three adjoining plots of one acre each were carefully laid 

 out. clearly demarcated, and securely monumented : 



Plot I. Was clear-cut of all existing woody growth except a few pitch pine and 

 planted with 2,650 2-year white-pine seedlings. The brush material derived from 

 the clearing operation was removed from the plot and burned. The cost of 

 cutting, removing, and burning the brush was $18.92. The planting cost, exclud- 

 ing the cost of the seedlings, was $10.84. 



Plot II. Was only partially cleared of its woody growth and planted with 1,825 

 2-year white-pine seedlings. Scattered pitch-pine trees 10 inches in diameter and 

 about 50 feet high were left, and a rather evenly distributed growth of aspen 

 2.5 inches in diameter and 35 feet high was also left uncut. The dense stand of 

 scrub oak beneath the two foregoing stories was completely removed, except an 

 occasional dominant shoot on a stool. These shoots were left primarily to reduce 

 subsequent sprouting. This object was fully accomplished, for in 1918 — that is, 

 after a period of seven growing seasons — only a sparse growth of scrub oak is 

 present. The cost of cutting, removing, and burning the brush was $19.89 and 

 the cost of planting $8.31. 



Plot III. Received no treatment prior to planting. The 2-year white-pine seed- 

 lings. 1.900 in number, were planted beneath the scrub oak, overtopped with a 

 story of aspen, and another of pitch pine and oak. The cost of planting was 

 $9.89. 



