11 is apparent that current growth of hardwoods is not 

 1 if high average value. Opportunities exist to improve 

 ibis situation by allowing growth to accumulate for a 

 |)i'riod of years so that stands will have more large- 

 .Nize trees on which new wood can be added. Further 

 improvement can be accomplished by making frequent 

 light cuttings to remove cull trees, weed trees, and 

 others unduly exposed to mortality. Fencing out 

 livestock often will help. 



Allowable Cut 



Cut Should Be Less Than Growth 



If the aim is to obtain larger and more valuable 

 yields in the future, the current annual harvest of 

 timber for lumber, pujpwood, fuel, etc., should not 

 exceed about two-thirds of the annual growth ac- 

 cording to calculations made during the survey.^ 



Current allowable cut for all growing stock is esti- 

 mated to be 247.0 million cubic feet including 523.8 

 million board-feet of sawtimber (table 18). Sixty-one 

 percent of the cubic foot figure represents hardwood 

 species. 



Of the estimated allowable cut of sawtimber, 78 

 percent is in the northeastern division (97 percent of 

 the softwood, 64 percent of the hardwood) (table 19). 



For the principal pulpwood species the annual 

 allowable cut totals 2,040,000 cords, practically all 

 of which is in the northraslcrn division (table 20). 



7 rends in Allowahle Cut Upward 



Comparison of allow-able cut estimates for 1936 and 

 1953 shows substantial increases for both sawtimber 

 and total growing stock (fig. 24). 



- .Allowable cut is the volume of merchantable live sawtimber 

 and poletimber that can be cut during a given period while 

 building up or maintaining sufficient growing stock to meet 

 specified growth goals. Several factors including distribution 

 of forest areas by types, species composition, and size classes, 

 togJther with the less tangible factors of operability and market 

 demand, influence the determination of annual allowable cut. 

 B?cause of the variable conditions encountered in statewide 

 inventory sampling, all factors that would actually determine 

 allowabi; cut on a managed forest could not be applied. But 

 in order to be as realistic as possible, field ci-ews judged sampled 

 stands for allowable cut about as they would for a prospective 

 tiinber sale, weighing operability as well as silvicultural factors. 

 For the northeastern division, a stand was not judged operable 

 unless the limber available for cutting exceeded 1,500 board- 

 feet per acre of sawtimber, or 3 cords per acre for pulpwood 

 cuts. In the southern districts where stands are more accessible, 

 the minimum operable cuts considered were 500 board-feet 

 per acre for sawtimber and 1 cord per acre for cordwood. 



Table 18. — Annual allowable cut of all growing stock, sawtimber 

 and poletimber on commtrcial forest land, by species, Minnesota, lO.'i.'i 



Species 



All growing 

 stock 



Sawtimber 



Poletimber 



Softwoods- 



Million 

 cu. ft. 

 6.0 

 5.3 

 29.7 

 18.3 

 6.8 

 18.0 

 5.1 

 6.3 



Million 

 bd.-ft. 

 25.0 

 21.8 

 83.3 

 17.2 

 23.9 

 30.2 

 7.0 

 14.9 



Thousand 

 cords 



9 





8 





131 





176 





18 



Balsam fir 



136 



Tamarack 



43 





36 







Total. 



95.5 



223.3 



557 







Hardwoods; 



Sugar maple 



2.5 

 1.2 

 .4 

 6.2 

 8.2 

 9.4 

 1.0 

 3.7 



90.4 

 4.6 

 1.2 



16.4 

 5.3 

 1.0 



6.8 



3.2 



1.9 



23.2 



32.5 



28.9 



4.1 



12.3 



133.5 



10.7 



5.4 



23.0 



12.1 



2.9 



13 





6 



Yellow birch 



I 





16 



Elm.. 



19 



Red oaks 



41 





2 



Other white oaks _ _. . 



14 





757 



Balsam poplar . .- 



28 









142 



.Ash 



34 





3 







Total 



151.5 



300.5 



1,076 







All species 



247.0 



523.8 



1,633 



T.ABI.E 19. — Annual allaivalile nil of sait'tinih,r and all growing stock 

 on commercial forest land, by .\pecies group and geographic division, 

 .Minnesota, 1953 



Class of material and species 



Total 





Divisi.jr. 





group 



North- 

 eastern 



South- 

 eastern 



Western 



Growing stock: 



Million 



cu. ft. 



95.5 



95.0 



56.5 



Million 



cu. ft. 



93.0 



81.0 



31.4 



Million 

 cu. ft. 

 1.0 



7.5 

 17.7 



Million 

 cu. ft. 

 1.5 



Aspen _ _ _ _. 



6.5 





7.4 







Total 



247.0 



205.4 



26.2 



15.4 







Sawtimber: 



Softwoods _ - _. 



Million 



bd.-ft. 



223. 3 



144.2 



156.3 



Million 

 bd.-ft. 

 216.8 

 133.6 

 59.3 



Million 



bd.-ft. 



3.0 



6.8 



67.7 



Million 

 bd.-ft. 

 3.5 





3.8 



Other hardwoods 



29.3 







Total... 



523.8 



409.7 



77.5 



36.6 







In sawtimber the annual allowable cut for while 

 pine, red pine, and spruce changed very little from 

 that recommended in 1936; tliat for aspen, oak, elm, 

 and basswood, however, increased greatly. 



Minnesota's Forest Resources 



23 



