H-USIT 



7/1S/30 



The spores rvliich irido iho wind froni the toad-stool or braxiket fungi v/on' t 

 all start trouble in e tree. They must hr.ve an opening already nade for them to 

 get in "before they can start sending those stron.5th sapping threads into the 

 heart ^ood of the tree. They can only enter some sort of wound. 



The butt rots of hard'jood trees in the East, Dr. Hartley says, are largely 

 tfaceable to forest fires. The fires leave the open scajrs which give the fxingous 

 spores a chance to get in. He thinks that if v;e could keep fire out of our 

 forests vre could prevent ^ largo proportion of the butt rot in hardwoods. That 

 •jould be a 'veil •.7ortl-.-',7hilo accomplislmont. He estimates that butt rot causes 

 the destruction of approximately one-sixth of the merchantable volume of our 

 hardT/oods. 



Those butt rots are not one disoase, but :r.ay be causodcy toad-stool spores 

 in one case, bracket fungi soores in another, or some other lesser Iciov/n f\ingi 

 in still another, ^en you figure that there arc about one hundred and eighty 

 species of forest trees in this co^ontry and that each kind may have several 

 diseases, you see 7/hat a job those forest pathologists have. Of course, one 

 kind of fungus '-.ay attack a number of different kinds of trees. In some cases, 

 hosvevcr, it scer-.s that there are .•iffsrent strains of the same kind of fungus and 

 some of the strains are better adrptod to one kind of a tree than to another. 



In the case of the firs piid pines, the most serious disease-causing fungi 

 enter through the branch stubs. Formally, the branches in a thick stand of pine 

 pxe shaded out, and drop off or breal: off, leaving on opening into the heart-wood 

 for the fungi. 



But these parasites rrhlch tap the heart of the tree and flourish in de- 

 generate prosperity by destroying the -^ood it has produced, are not the only tree 

 parasites. There are siso flo'7ering plants, \7hich have taken up this manner of 

 living on the tree. 



The best knorm of all tree parasites is probably our common mistletoe, 

 v/hich clings to the oak and or.hcr trees. This v/oll laiovm mistletoe. Dr. Hartley 

 says, is comparatively harmless. It has leaves and manufactures p?rt of its 0T,7n 

 food. All through the Test, except in the wetter regions, however, there are 

 lesser-lcio'Tn, but more definitely parasitic, mistletoes v;hich attack pine on<i 

 fir and cause a big reduction in luiriber quality and quantity. These are likev/ise 

 flov/ering plants, but have no leaves. 



Dr. Hartley tells me that on a badly infested Douglas fir he has had to 

 hunt for fifteen minutes to find enou^ of the western fir mistletoe to show to 

 a lumberman. That v/as because the plant is so completely parasitic that the 

 vegetative parts ere rll down in the bark, below the surface where they can't 

 be seen. The parts which produce the berries are very small and very scattered. 



This mistletoe tgkos its food altogether from the tree on which it lives. 

 In doing so, it causes the tree to grow in distorted shapes, cuts down the tree's 

 rate of growth, and finally kills it. As a result, there is not only less 

 lumber obtained from the tree than there otherwise v/ould be, but sections of the 

 tree have twisted grain which makes them -unfit for lumber. 



