SILVICULTURAL MANAGEMENT OF BLACK SPRUCE IN MINNESOTA 47 



and permits easy and relatively prompt salvaging of any trees that 

 may blow down along the edge. 



However, it would require 600 to 800 feet of timber "frontage" to 

 furnish 1 acre of cutting area. Therefore, cutting would have to be 

 spread over a very large area to obtain a substantial quantity of pulp- 

 wood — a considerable disadvantage from a practical standpoint. 



CHRISTMAS TREE OPERATIONS 



In 1940 black spruce Christmas tree stumpage from stagnant 

 swamps made up 6 percent of the receipts for sales of State-owned 

 timber in Minnesota (26) . Accordingly, it is evident that not all "non- 

 productive" swamps are valueless despite their classification. 



Most of the trees cut in low-grade swamps are used for table-size 

 Christmas trees, 18 to 30 inches in height. However, these market- 

 able sections are usually the tops of trees that stand 12 to £5 feet in 

 height and range in age from 80 to 140 years old. 



The stands that produce the tree tops which meet the rather exact- 

 ing requirements of the table-tree market are exceedingly dense. 27 

 Since they usually support 3,000 to 5,000 stems per acre, the trunks on 

 the trees are bare of live limbs for half or more their length, and only 

 a few feet at the tips are free-grown. The 30-inch top sections are 

 from 8 to 12 years old. 



In sales of Christmas tree stumpage made by the Minnesota Forest 

 Service, the cut is restricted to a maximum of 10 percent of the total 

 stems on the area. However, few stands contain that large a percent- 

 age of acceptable trees. Cuts of from 150 to 200 trees per acre are 

 about average and 400 trees per acre is exceptionally high. Since the 

 merchantable top sections are only about 10 years old, it is expected 

 that many of the trees which are unacceptable at the time of a cutting 

 operation will by later growth produce an acceptable top. Further- 

 more, it is believed that the thinning brought about by the removal of 

 up to 10 percent of the trees will result in improved growth on the 

 remainder. In a few instances second cuts have been made. The 

 results have fully met expectations. 



There is good reason to believe that at least 5 or 6 cuts can be made 

 at intervals of 10 years before the present even-aged stands will have 

 been too much culled or thinned for further production. There has 

 not been sufficient time to show whether the stands will reseed nat- 

 urally and change gradually into all-aged forests that can be man- 

 aged by the selection system for Christinas tree production. 



When black spruce is cut with a stump 3 to 5 feet high so as to leave 

 several of the lower branches, one of them may turn up to form a new 

 leader. In stagnant swamp forests of the kind described above, there 

 seldom are opportunities to encourage growth of new tops for future 

 Christmas trees by this method. The trees are too crowded and the 

 lower branches are too suppressed. But where Christinas trees are 

 cut from reproduction on more fertile swamps or uplands, it is sug- 

 gested that stumps be cut sufficiently high to leave about three whorls 

 of thrifty branches to produce one or more new leaders unless there 

 are neighboring trees that will crowd and suppress them. 



27 Information on Christmas-tree-cutting operations on State lands was largely 

 received from Mr. Raymond Clement and other members of the Division of 

 Forestry, Minnesota Dept. of Conservation. 



