INVESTIGATIONS OF THE ROTTING OF SLASH IN ARKANSAS. 3 



these methods. It will be necessary in discussing the various methods 

 of brush disposal to take into consideration the types of timber being 

 cut. In the Ozark National Forest the main timber is white oak 

 (Quercus alba) intermixed with black oak (Q. velutina), post oak, 

 (Q. stellata), and several other species of minor importance, while on 

 certain areas some shortleaf pine is found. In the Arkansas National 

 Forest the bulk of the timber to be logged is shortleaf pine. 



The investigations of the rotting of slash in Arkansas were car- 

 ried on in the Arkansas and Ozark National Forests on areas which 

 had been logged from 1 to 10 years. All of the areas examined which 

 had been logged for more than five years were on private or patented 

 lands, but located within these National Forests. The conclusions 

 reached from these studies should be applicable to all of the other 

 areas in these two forests, since the underlying principles are identical 

 and the climatic conditions very similar. 



WHITE-OAK SLASH. 



FUNGI WHICH ROT THE SLASH. 



Four main fungi were found rotting the white-oak slash, viz, 

 Stereum rameale, 8. versiforme, S. umbrinum, and S. fasciatum. All 

 are sap-rotting fungi which cause but little apparent change in the 

 texture of the wood. They produce what might be called indeter- 

 minate rots, since there are no well-defined characteristics which 

 mark any one of them. All slightly discolor the wood, which later 

 becomes whitish in color, lighter in weight, and easily broken. 

 Strange to say, each of these fungi rots its own special portion of 

 the slash. Stereum rameale is usually found attacking twigs which 

 bear the leaves and very small branches (1 inch or less in diameter). 

 This fungus seems to begin on the twigs and works gradually down 

 them to where the branches are about 1 inch in diameter; there two 

 other fungi (S. versiforme and S. umbrinum) take up the work and 

 rot the small branches up to 2 or 3 inches in diameter, where a fourth 

 fungus (/S. fasdatum) usually begins its attack on the wood. This 

 is the main fungus which rots the sapwood of the logs and large 

 branches 3 inches or more in diameter, and it is often found rotting 

 the sapAvood of the stumps as well as the boles and large branches 

 of standing dead oak trees. None of these fungi destroys the 

 attacked wood completely, its final disintegration being left to 

 other groups of fungi, insects, etc. 



The heartwood of the large branches and trunks remains for many 

 years after the sapwood is destroyed, but meantime it is being slowly 

 rotted by a delignif ying fungus (Stereum frustulosum) , which pro- 

 duces small cavities or pockets in the wood. 



Other fungi of minor importance were found attacking the oak 

 slash, the most important of which was a small, dark-brown, gelat- 



