Forest Renewal 



Gullying of forest land is healed in time by tree growth. 



tween amount of seed produced and 

 the seedlings established is that abun- 

 dant sources of seed must be kept avail- 

 able. Often that means the necessary 

 seed source must consist of well-stocked 

 blocks, strips, or other bodies of mature 

 trees. The jack pine, Douglas-fir, and 

 lodgepole pine are typical species for 

 which block methods of clear cutting 

 are providing satisfactory conditions 

 for forest renewal. 



Some species produce such copious 

 crops of seed at short intervals that re- 

 newal can be accomplished by leaving 

 individual trees well distributed over 

 the cutting area. For these, a modified 

 clear-cutting method called the seed- 

 tree system, has proved suitable. Suffi- 

 cient seed for necessary renewal is pro- 

 duced by a dozen or more mature trees 

 an acre. If maturity is judged on the 

 basis of small-sized products such as 

 pulpwood, which can be produced 

 from young trees, seed production may 

 not yet have reached a very high level 

 and the method may fail because of the 

 lack of sufficient seed. The lack may 

 be offset by leaving more seed trees 

 per acre, in which case the method 



approaches and may actually become 

 the shelterwood system. Such a tend- 

 ency toward the shelterwood is also 

 characteristic of species that demand 

 full light for good development, but are 

 poor producers of seed. The seed-tree 

 method is often effective with such 

 wind-firm species as the Virginia pine, 

 the slash pine, and loblolly pine, al- 

 though the shelterwood method is 

 favored by many for the last two. 



WITH MANY of the various methods 

 aimed at the production of even-aged 

 stands, additional measures designed 

 to make more efficient use of the seed 

 will pay dividends. Since most wind- 

 borne seed germinate best in contact 

 with mineral soil, some form of rough 

 cultivation, either immediately before 

 or after seed fall, is effective. This op- 

 eration is usually accomplished by a 

 heavy tractor and disk combination 

 and is necessarily limited to rather 

 smooth ground. It is particularly effec- 

 tive where winter logging on snow or 

 the logging equipment does not ac- 

 complish much scarification of the 

 forest floor and exposure of mineral 



