The harvesting opportunity is limited as 

 well by the volume of timber available per 

 acre and by the cost of road development. In 

 developed areas it is sometimes possible to 

 harvest volumes of 1,000 board feet per acre 

 or less. Data are lacking to show timber avail- 

 able in relation to development cost. Generally 

 speaking, timber can be harvested if the vol- 

 ume available in trees of merchantable size 

 over large areas exceeds 5,000 board feet per 

 acre, unless problems of access and develop- 

 ment are severe. Of the 1,850,000 acres of 

 sawtimber in the study area, 1,633,000 acres 

 support 5,000 board feet or more per acre. 



One of the more urgent problems facing 

 the Northern Region is to complete an in- 

 ventory of white pine stands of harvestable 

 size and determine priorities for harvesting. 



Nonmerchantable Stands 



The nonmerchantable stands, like the mer- 

 chantable stands, represent a wide range of 

 situations, and each stand has to be considered 

 individually. Also, each stand has to be con- 

 sidered in relation to the operability and 

 quality of the land it is growing on and in 

 relation to the management goals set for the 

 Forest. 



Depending on their age, size, vigor, and 

 species composition, and on the quality and 

 character of the land on which they are grow- 

 ing, nonmerchantable stands present a variety 

 of possibilities. Some may offer few manage- 

 ment opportunities either because nature alone 

 is doing a good job or because any improve- 

 ments in the yield would be small in relation 

 to the costs involved. In addition, some of the 

 pure or alrhost pure white pine stands are so 

 near gone that there is no alternative but to 

 start over with a new stand of some other 

 species or mixture of other species. 



The majority of the immature stands, how- 

 ever, are mixed species. If these are over- 

 stocked, thinning is always a management 

 possibility. Any diseased white pine trees in 

 these stands can be removed in the thinning 

 treatment. , 



Stands in the younger age classes (fig. 1) 

 are generally thought to offer the best thin- 

 ning opportunities, because capabilities for 

 growth response generally decrease with age 

 as well as with increases in stocking and loss 

 of crown. According to surveys made in 

 1958-61, of the 1,368,000 acres of pole size 

 and smaller timber, 693,000 acres supported 

 stands that originated after 1929, and of these, 

 1 2 1 ,000 acres supported stands that originated 

 after 1949. Since the 1958-61 survey, an ad- 

 ditional 100,000 acres of new stands have 

 been established on white pine land, 52,000 

 acres by planting and 48,000 by natural re- 

 generation. 



For the most part these stands are well 

 stocked with potential crop trees'* that will 

 produce good timber products. Many of the 

 221,000 acres of stands originating since 1949 

 have already been examined to evaluate thin- 

 ning opportunities, and data from these exam- 

 inations suggest that most of this land is well 

 stocked in terms of potential crop trees. These 

 data suggest that if the stands examined are 

 representative of the 221,000 acres, then 

 190,000 acres have 200 or more potential 

 crop trees per acre, in the following pro- 

 portions: 



Potential crop 



Thousand 



trees per acre 



acres 



Less than 1 00 



2 



100-199 



29 



200 - 299 



60 



300 - 400 



86 



Over 500 



44 



Total 



221 



One of the problems of this area is that the 

 potential crop trees are growing in competition 

 with many trees that are excess to the needs 

 of the stands. Some stands, principally plan- 

 tations, have relatively few excess trees per 

 acre. However, one-third of the stands that 



^In stand examinations, potential crop trees are 

 identified with reference to tree c/uality and distribu- 

 tion. Tiiese are the trees that would be featured if the 

 stand were to be thinned. 



