46 
BULLETIX 1402, U. 
DEPART^IEXT OF AGRICULTURE 
In two other and more representative townships in the east side 
yellow pine type the average number of potential seed trees (IS 
and 20 inches combined) is 1.6 per acre, representing about 500 
board feet per acre, or 3 per cent of the total stand. Such timber 
stands, which unfortunately appear to be fairly common, can not 
be taken care of by any reasonable diameter limit. The trees of 
desirable sizes simply are not on the ground to leave. The only 
alternative to insure restocking is to leave some larger trees to 
reseed areas where no small trees are available. A total volume of 
1.000 to 1.500 board feet per acre (including the small trees pre- 
sent) will usually be sufficient. 
perce:nta6e: of differeint areas 
10 20 30 40 50 60 70 80 
90 100 
SUFFICIENT SEED TREES 
%. ENOUGH SEED TREES 
2/3 ENOUGH SEED TREES 
I I /3 ENOUGH SEED TREES, OR LESS 
Fig. 18. — Percentage of areas iu the important timber types fully supplied with seed 
trees, and those inadequately supplied. An area with 1 seed tree per acre is character- 
ized as one-third supplied : Vith 2 trees per acre as two-thirds supplied : 3 as three- 
fourths : 4 or more as fully equipped. So classified, most of the areas examined in the 
different timber types are 'well provided for. having generally less than 20 per cent of 
area one-third equipped. Yellow pine, however, has as much" as 58 per cent of area in- 
adequately supplied. Cutting to the '" seed tree limit '" of 20 inches in diameter in 
yellow pine is not sufficient. Particularly under east-slope conditions it proves neces- 
sary to leave occasional large trees to supplement the smaller seed trees 
The east side yellow pine type appears to be deficient to a vary- 
ing degree in small seed trees. The stand data cited show certain 
areas well provided and others less than half supplied, assuming 
that the -4 small trees per acre basis is sound. It is safe to figure 
forties with 4 or more seed trees per acre as adequately provided, 
those with 3 trees as three-fourths provided, those with 2 trees, two- 
thirds, and those with 1 tree one-third. On this basis these two 
townships mentioned as deficient would be, respectively. 53.1 and 
53.8 per cent stocked with seed trees if cut to a 20-inch diameter 
limit. (Fig. 18.) 
