32 YELLOW POPLAR IN TENNESSEE. 



with chestnut, red oak, locust, and other species which sprout. The ro- 

 tation or period required for the maturity of a coppice stand is from 20 

 to 35 years. Sprout trees which are much older than 35 years, frequently 

 become so defective at the butt that they break off. Sprout stands should 

 be even-aged or in even-aged groups. 



High forest forms. For the production of saw timber, yellow poplar 

 can be managed only with seedling trees in high forest. Of the different 

 high-forest forms, yellow poplar is well suited only to even-aged stands, 

 in which all the trees in one cutting unit or block are of the same age or 

 approximately so ; or to a group or strip form in which the trees occur 

 in even-aged strips or groups. The groups or strips can be made so small 

 as to develop a group or strip selection form. Such stands can be either 

 pure or mixed. The single tree selection form of forest (which consists 

 of trees of all ages mixed in the stand) with its more restricted light con- 

 ditions is not so well adapted to securing the replacement of yellow pop- 

 lar. The group and strip forms seem to particularly meet the require- 

 ments of yellow poplar in mountain forests. 



( 1 ) The advantage of the group or strip forms are that profitable cut- 

 tings of large timber can be made in the same cove or valley at short in- 

 tervals. When the growth is rapid, the intervals between cuttings might 

 not exceed 15 years. 



(2) Since the mature groups are cut clean, there is no breakage of 

 small timber in felling as is the case when culling and simple selection is 

 practiced. 



(3) Large timber can be logged to loaders by cable with less serious 

 breakage of small trees. 



(4) Restocking with yellow poplar and white pine is more easily ob- 

 tained in the center of openings, while nearby oaks seed up the edges. 



(5) The soil is better protected from erosion than it is in the case of 

 clean cutting, and there is less danger of destruction by fire on the cut- 

 over areas. The intermixture of species with heavy crowns, likewise as- 

 sures protection of the soil from drying winds. 



(6) With groups of young timber adjacent to groups which are ma- 

 ture, more intensive management can be practiced than is possible in the 

 case of selection stands. It is possible to make thinnings in groups of im- 

 mature trees, thus freeing the larger trees in these groups, and accelerat- 

 ing their growth. At the same time, the small timber which is removed 

 in thinnings, and which otherwise would be lost, can be utilized. 



Applying this method of cutting to a farm forest of 100 acres in which 

 an ideal form of stand has already been developed, there would be one 

 group of trees which would be mature and which would be cut that year or 

 during the cutting period, which might be as long as 10 years. If 50 years 



