FOREST DISEASE SURVEYS. les: 
upon all such areas in which the newly transplanted seedlings are 
subject to infection by fungi or mistletoe. Many of the plantatien 
sites of this region are located upon burned-over areas, and the 
majority of these are so badly fire swept that very little has been 
left in the form of coniferous hosts for forest-tree diseases. How- 
ever, to review the succession of plant life on a burned-over area, 
after a fire which has been sufficiently intense to destroy every vestige 
‘of humus and litter, is to find that the alternative hosts of some viru- 
Fic. 14.—Typical rot of brown:cedar poria in butt and roots of cedar. Note 
the laminations of the rot and (on the left) the fruiting of the fungus. 
lent needle or twig diseases have invariably appeared. In many cases 
the new plant succession carries with it alternate host plants of im-— 
pertant forest-tree rusts which soon bear their parasitic fungi, and 
some of these are found to menace the young tree growth upon the 
area. A disease survey of such a site is very necessary, especially 
if the site is to be used as a plantation area for susceptible seedlings. 
_DISEASE-SURVEY METHODS. 
The most practicable methods only are to be applied by unit 
crews in gathering forest-disease data. These metheds should be ap- 
pled with a reasonable knowledge of the principal destructive disease 
