APPENDIX CRITERIA FOR RATING PRODUCTIVITY 683 



Table 92. — Trees required per acre Jor full stocking, by tree size and jorest type group, Lake States Region 



Diameter breast high (inches) 



Aspen-paper 



birch type 



group 



Spruce-fir 

 type group 



White-red-jack pine type 

 group 



Maple-beech- 

 birch type ' 

 group 



Oak-hickory 





Jack pine 



Red and 

 white pine 



type group 



Reproduction 



Number 



1,000 



800 



600 



360 



230 



150 



110 



80 



60 

 48 



Number 



1,000 



800 



600 



560 



330 

 210 

 150 

 120 



100 

 80 

 65 

 50 



45 



Number 



1,000 



800 



600 



400 



260 

 180 

 130 

 100 



75 

 60 



Number 



1,000 



800 



600 



500 



300 

 200 

 140 

 100 



80 

 62 

 50 



42 



35 

 30 

 26 

 22 



Nu)7iber 



1,000 



800 



600 



400 



250 



175 



120 



90 



70 

 60 

 50 

 40 



36 

 30 

 26 

 22 



20 

 17 

 15 



Number 



1,000 



2 .. - - - - - - - 



800 



4 - -_. _ 



600 



6 



270 



8 - ._ _ 



180 



10 



125 



12 -- - 



95 



14 .. - 



71 



16 - -- -- - 



56 



18 



45 



20 -- 



37 



22 







30 



24 -- 







25 



26 . . - . 









28 -- -- 











30 











32 ._ 











34 ..-__-_ 













36 - - 

























' Also used for elm-ash-cottonwood stands. 



Oak-Hickory Type Group 



Prospective stocking was considered only if the 

 stand was cut less than 3 years prior to examina- 

 tion. The standards for judging prospective 

 stocking in relation to number of seed trees per 

 acre are given in table 93. Those based on 

 proximity of the stand to a margin of trees of 

 seed-bearing age are given in the following 

 tabulation: 



Heavy-seeded species. 



Light-seeded species. 



Tistance from 



stocking 



seed source 



expected 



(,chains) 



(■percent) 



0-2 



100 



2-4 



50 



4+ 



20 



0-5 



100 



5-10 



75 



10-20 



25 



20+ 







Effect of Felling Age 



Table 94 shows the felling-age factors used in 

 adjusting the productivity ratings for the various 

 forest type groups. 



In rating productivity in the maple-beech-birch 

 type group, no reduction was made for felling age 

 if the cutting removed trees that were principally 

 "acceptable" or "noncount" species and there was 

 a good stocking of reproduction of desirable species 



on the ground. Where such conditions did not 

 exist, the standai-ds in table 94 were applied. 



Felling factors for the various species found in 

 the oak -hickory type group were taken from other 

 type tables which included the species cut or 

 which had similar growth habits. 



Table 93. — Relation of expected stocking to number 

 of seed trees per acre in the oak-hickory type group, 

 type of seed, and tree size class, Lake States 

 Region 



Heavy-seeded hardwoods 



Light-seeded 

 hardwoods 



Stocking 



12- to 16-inches 

 d. b. h. 



17- to 



26-inches 



d. b. h. 



12- to 

 16-inches 

 d. b. h. 



17- to 



26-inches 



d. b. h. 



expected 



Number 

 2 



Number 

 1 

 2 

 3 

 4 

 5 

 6 

 7 

 8 

 9 

 10 



Number 



Number 



Percent 

 10 



4. . _ 



1 

 2 



i" 



20 



6 



30 



8 



40 



10 . _- -- 



3 



4 



-- 



50 



12 - 



60 



14 



70 



16... - 



5 

 6 



7 



§" 

 4 



80 



18 - .- - 



90 



20 



100 







