6 BULLETIN 191 



pine, it seemed to be distributed much more uniformly than in the 

 mixed stands. 



Silvicultural conditions. Certain silvicultural conditions appeared 

 to favor the" presence and spread of the disease. It was predominant 

 especially in tracts which were in need of thinning. A notable case 

 of this sort was found in Orange County where the trees ranged from 

 6 to 14 inches in diameter at breast height and were growing so close- 

 ly together that the wind had broken many branches. The heavy mass 

 of crowns did not allow the entrance of sunlight, which is an important 

 factor in the healthy growth of a forest. 



Topography. So far as could be determined, the effect of topog- 

 raphy upon the presence of the fungus seems very slight. The reports 

 of lumbermen on this point were variable and evidently were governed 

 by local conditions. Comparison of the opinions of lumbermen in dif- 

 ferent localities, strengthened by the writer's observations in the woods, 

 leads to the conclusion that red rot lumber is as common on high rocky 

 land as in the swamps and lowlands, with the exception of tamarack 

 which, of course, occurs only in lowlands. 



Wind. It is believed that the wind is a more important factor 

 than topography. Areas exposed to heavy winds show more red rot 

 decay than do sheltered stands. This condition might be explained 

 by the fact that the damage done by the wind in breaking branches 

 leaves open places or branch wounds where the fungus may enter the 

 tree. The wind also aids in carrying spores from one tree to another. 



Age. Previous writers have ascribed much importance to the 

 supposed fact that only the oldest trees in the stand are affected. While 

 this may be true in some sections, many specimens of trees not more 

 than 25 or 30 years old were found by the writer to be infected. 

 Von Schrenk's statement that the fungus attacks living trees only after 

 they have reached the age at which they form heart-wood, probably is 

 a more correct conception of the matter. 



IV. DISTRIBUTION 



Numerous German references report the occurrence of this fungus 

 in all parts of that country where any considerable stands of coniferous 

 trees are found. Moller (5) says "It is present wherever the conifers 

 grow in any abundance and the damage caused by it reaches into the 

 millions of dollars annually." Hartig (1) states that it is very abun- 

 dant in the pine woods of North Germany and occurs also, but less 



