ESTABLISHING FORESTS BY PLANTING 



395 



In all methods of producing layers the rooting is facilitated by 

 the rupture of the bark at the point where the branch is brought 

 beneath the soil. With thick, hard-barked species a ring of 

 bark may be removed or a notch cut on the lower side a third of 



FIG. 108. 

 A. Layer from a bent-over branch. 



B. Aerial layer. 



the way through the stem. As a rule, 2-year wood roots more 

 freely than 1-year. The effect of cutting through the bark is to 

 stimulate the formation of callus from which the roots later develop. 

 Only a few forest trees propagate freely from layers. Beech, 

 elm, and ash root freely in a single year. With many species 

 it takes 2, or even 3, years. Layers should not be removed 

 from the parent tree until they are well rooted. In stands of 

 young sprouts, stool shoots of beech, ash, and basswood can be 

 brought on their own roots by bending over the 2- or 3-year 

 shoots and treating them as described above. When the old 

 stumps are defective the stand can be greatly improved in this 

 way. When the layers are well rooted their connection with the 

 parent tree is severed and they become independent plants. 



40. PLANTING ROOT SUCKERS 



The use of root suckers in planting operations is necessarily 

 confined to a limited number of broadleaved species, viz., those 

 that freely develop shoots along their surface roots. The species 



