FORESTRY. 



EDITED BY DR. B. E. FERNOW, 



Director of the New York Scheol of Forestry, Cornell University, assisted by Dr. John C. Gifford of the same 



institution. 



It takes thirty years to grow a tree and thirty minutes to cut it down and destroy it. 



DISEASES OF TIMBER. 



The presence of a dead tree in a forest, 

 or the rotting of structural timber, was a 

 matter of small moment to the past gen- 

 eration, for with such a large supply to 

 draw on, the dead trees could be ignored 

 and the rotten bridge timber could be 

 quickly replaced. 



At the present time, however, when we 

 no longer can count on the supply of 50 

 years ago, it is a matter of concern where 

 the great quantities of timber are to come 

 from in the future, especially when we re- 

 flect that the railroads alone use, every year, 

 100,000,000 ties and the telegraph and tele- 

 phone companies several million poles. We 

 are not yet face to face with a timber 

 famine, nor are we likely to be there for 

 many years ; but it behooves us to consider 

 what is coming, for no country, however 

 large its reserve may be, can look with 

 impunity on the withdrawal of such quan- 

 tities as indicated above. 



How best to conserve the existing supply 

 is the problem with which the forestry of 

 today has to deal. It will develop in sev- 

 eral directions. In the first place, it will 

 be the endeavor to cut the existing supply 

 on a more rational and economic basis. 

 A second line of work will deal with the 

 reforesting of denuded areas and the plant- 

 ing of treeless districts ; while a third will 

 be directed toward getting an increased 

 service out of the timber after it is cut. 

 Wood, when cut from the tree, decays in 

 the course of time and has to be replaced. 

 By increasing the length of life, so called, 

 of a piece of wood, correspondingly less 

 timber will be cut, and in that way the ex- 

 isting supply will be conserved. 



Decay of wood, whether it be in the 

 live tree or the dead wood, is caused by 

 the growth, in the wood, of various low 

 plants called fungi. The fruiting bodies of 

 these fungi are the familiar toadstools, 

 frogstools, punks, or mushrooms found on 

 trees. The punks liberate millions of mi- 

 ' nute spores, which germinate or sprout in 

 some old knothole, or, in the case of dead 

 timber, on its surface, and grow into the 

 sound wood, therebv cau.sing it to decay. 

 When enough food has been extracted 

 from the wood, one or more new punks 

 . form on the outside. 



There are many different kinds offungi 

 growing on trees. Some grow only in the 

 live parts, where thev may kill the leaves, 

 the living wood, or the roots. Others 

 grow only in the heartwood of living trees. 



Some trees are attacked more than others. 

 Forty per cent of the red fir in central 

 Oregon is diseased because of fungus, while 

 the mountain pine of Northern Idaho is 

 so badly diseased that it is often impos- 

 sible to find a tree entirely free from it. 

 The spores of this fungus are blown about 

 in the forest, and get into wounds caused 

 by the breaking off of branches. Older 

 trees alone are attacked, as it is only in 

 these trees that the branch has formed 

 heart-wood. 



One fungus (Polyporus schweinitzii) en- 

 ters coniferous trees through the root. 

 It is the cause of the butt rot of the older 

 trees. The heartwood has turned into a 

 dry, brittle mass, which may extend one 

 to 60 feet up the trunk. Trees affected 

 with this disease usually break off near 

 the ground during storms,. 



A distinct class of fungi grows only on 

 dead timber. Their spores alight on the 

 outside of a dead tree, and as the fungus 

 grows into the wood it destroys the fiber. ' 



The decay of railway ties, bridge and 

 mine timbers, fence posts, etc., is caused 

 by a number of these fungi. When, placed 

 in positions where these timbers are left 

 moist, decay will set in from the outside. 

 This decay makes it necessary to remove 

 timbers frequently, involving the cost of 

 removal as well as the cost of new timber. 

 When one reflects that white oak railway 

 ties last on an average only 8 years, it is 

 easy to understand what enormous destruc- 

 tion these fungi do. 



One of the great problems of to-day is 

 to find how the destruction of timber by 

 these fungi may be prevented. The trees 

 in the forest when once attacked can not 

 be saved. In some places where perma- 

 nent lumbering operations are being carried 

 on it will be possible to cut down all dis- 

 eased trees, so as to save at least a portion 

 of the tree. This cutting will prevent the 

 formation of fruiting bodies, the snores of 

 which might infect other trees. In Ger- 

 many, where systematic forestry has been 

 carried on many years, it is difficult to find 

 a diseased tree at this time. As older trees 

 are the ones usually attacked, it follows 

 that when we once know where the danger 

 limit begins, it will be desirable to cut all 

 trees which reach that limit.. 



The decay of structural timber can be 

 prevented for a considerable period bv 

 properly drying lumber before using it. 

 Much is vet to be learned as to the length 

 of time necessary to drv timber so as to 

 increase its length of life. 



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