CHESTNUT BLIGHT 11 
DETERIORATION OF WOOD 
Tests made by the United States Forest Products Laboratory ” 
indicate that for a year, or possibly two years, wood from blight- 
killed chestnut is as good as that from healthy chestnut. As the . 
blight fungus itself does not appear to have any immediate or after 
effects upon the mechanical strength of the timber; the utilization 
value of a blight-killed chestnut should be no less than that of a tree 
ringed with an ax at the same time and left standing. Soon after 
the death from either cause, the loosening of the bark, which is ac- 
companied by decay of the sapwood, becomes apparent. Figure 10 
shows the average rate at which the bark was observed to loosen and 
“G 
VEARS DEAD 
(Ml) Pee CENT OF BARK OFF 
BZA PER CENT OF BARK LOOSE 
MME PER CENT OF BARK TIGHT 
Ficura 10.—Condition of bark on trees dead for periods of different length 
fall from the first log of blight-killed trees at several localities in the 
southern Appalachians. The very rapid loosening during the first 
three years after death is brought about largely by insects and fungi, 
which finally cause it to slough off. Occasionally certain species of 
fungi also decay the heartwood to a depth of an inch or more. The 
amount of sound sapwood remaining on the first log during the first 
seven years after death is approximately the same as the amount of 
tight bark shown in Figure 10. ; 
“Since most of the loosened bark and decayed sapwood will be 
knocked off in felling operations, they can be considered almost a 
complete loss by the third or fourth year after death. The reduc- 
tion in volume resulting from the loss of sapwood and bark on the 
trunks alone, where trees were cut into 5-foot sticks to a 4-inch mini- 
mum diameter for extract wood, is shown in Figure 11, which is 
2A UTILIZATION GUIDE FOR BLIGHT-KILLED CHBSTNUT. U. S. Dept. Agr., Forest Prod- 
ucts Lab., Technical Note 224. [Multigraphed.] 
