165 and the large-toothed aspen 93, a total for the two species of 258 per acre, and they thus comprise 41 per cent of the stand. Nearly 90 per cent of these trees have not yet attained commercial size, if we regard those as non-commercial which are less than five inches in diameter at breast height, that is, the height at which the trees were measured. By using a volume table for poplar, it is calculated that the trees of this species now of commercial size, yielding only one cord of pulpwood per acre, would run 17,000 cords on the whole area burned once. Yet, if the 230 trees per acre under commercial size, or the normal percentage of them, were allowed to come to maturity, the outlook for pulpwood as a secondary product to the pine would be more hopeful.
The other commercial trees, whose rate of occurrence is given in the table (page 175), probably had only a scattering distribution in the original forest. The oak, cedar, balsam and hemlock occur in sufficient quantities—in the aggregate 100 trees of all kinds per acre—to form a valuable commercial adjunct if allowed to come to maturity.
AREAS SEVERELY BURNED TWICE
The areas indicated on the map (facing page 166) as burned twice aggregate 26,000 acres. In these are 1,750 acres which escaped the second fire, and hence these were classed among the areas burned once. Deducting this amount, and the 25 per cent estimated to be occupied by swamps of various kinds, there are 17,750 acres actually burned twice. The two severe fires on the Methuen areas occurred approximately 25 years and 16 years ago. Patches too small to be delimited were burned eight years ago, and there are indications of numerous local ground fires. One of these marked some of the trees five years ago. The two severe fires on the Burleigh areas occurred 25 years and 8 years ago, while the fires of 16 years and 5 years ago were light, and only left their scars in some places.
The largest area burned twice is found in southern and south-eastern Methuen and comprises, exclusive of swamps, 8,760 acres, but 28 per cent of this escaped the fire, so that the area actually burned is 6,300 acres. Although a relatively large proportion escaped, the fires were very severe upon the pine reproduction on the areas actually burned, since it now averages only 1.3 pine trees per acre, whereas, before the second fire, the area averaged 33 pine trees per acre. The second fire then practically obliterated the potential pine stand. The area burned twice around Bottle and Barrette lakes now contains five young pine trees per acre. Only one small unburned patch was discovered, and this contained young pine at the rate of 50 to the acre.