46 CIRCULAR 7 91, U. S. DEPARTMENT OF AGRICULTURE 



method consists simply of clear cutting parallel strips and leaving the 

 intervening areas uncut to provide seed. The tests of strip cutting 

 reported here all dealt with thrifty stands. 



One of the earlier trials of strip cutting was undertaken by the 

 Minnesota Forest Service. The alternate clear-cut and uncut strips 

 were each 330 feet in width — too wide to insure adequate seeding. Xo 

 systematic follow-up of results was made, but some rather casual in- 

 spections about 10 to 12 years later led to the conclusion that repro- 

 duction had been only moderately successful and that the timber in 

 the uncut strips had suffered considerable mortality. 



A similar experiment was begun at the Cloquet Experimental For- 

 est in 1927, but the strips were made only 75 feet wide (16). Strips 

 were laid out in a northeasterly direction, at right angles to the prevail- 

 ing wind. Within 3 years both the cleared strips and the uncut strips 

 were abundantly stocked with seedlings. Unfortunately, the results 

 as to success of reseeding were soufewhat clouded because much of the 

 live sphagnum had been picked from the area for nursery packing 

 material. The uncut strips suffered serious mortality — 32 percent in 

 the first 3 years. A little over half of these trees were lost through 

 windthrow and the remainder had died standing. 



It was thought that locating strips parallel with the prevailing wind 

 might give the uncut timber greater protection; hence, a strip-cutting 

 experiment was tried on the Kawishiwi Experimental Forest with 

 strips that ran east and west. In this instance the strips were made 

 100 feet in width. Six years later there were about 2,600 black spruce 

 seedlings per acre in the cleared strips and 3,200 in the uncut strips. 

 About half as much reproduction was present on the area immediately 

 prior to logging. In the same 6-year period the trees in the uncut 

 strips made a net gain in volume of 2.1 cords per acre or 9 percent 

 despite some losses from windfall and exposure along the edges. The 

 results in this instance were favorable although the stand was also well 

 adapted to partial cutting. 



Another strip-cutting test was tried more recently in Koochiching 

 County. It was similar in lay-out to the preceding one but the west 

 ends of the strips adjoined a new clear cutting. Within a few weeks 

 after clearing the strips a hard wind struck the area and caused exten- 

 sive uprooting in the uncut strips. The new windfalls and remaining 

 live trees were salvaged immediately. 



On the whole, the results of these four tests of clear cutting in alter- 

 nate strips were rather discouraging, although further trials may 

 bring out more information in favor of strip cutting. The method is 

 not suited to badly overmature stands that must be cut at once to 

 obtain the maximum recovery of merchantable material. The kinds 

 of stands where it has greatest promise are likely to be reasonably well 

 adapted to partial cutting, a method that should give higher yields 

 in the long run. 



Kecently another type of strip cutting — the removal of a 50- to 75- 

 foot strip along the leeward side of the stand at 1- to 3-year intervals — 

 has been suggested for the management of black spruce in Michigan 

 (10). In principle, this method appears to be just about ideal for the 

 growth of black spruce in even-aged stands under a simple form of 

 management. It provides for abundant seed on freshly cleared soil, 

 gives maximum wind protection to the exposed edge of the timber, 



