38 BULLETIN 244, U. S. DEPARTMENT OF AGRICULTURE. 



In a year's forest cut of shortleaf timber the average loss by red- 

 heart was 11 per cent of the total cut. The trees were mostly 

 between 60 and 180 years old, some being 200 years old. 



The wounds through which the spores enter the tree are caused 

 partly by wind and sleet storms breaking the branches, but more 

 largely by fires, which kill a portion of the sapwood, thus exposing 

 the heartwood to infection. Thrifty young trees are to a consid- 

 erable extent protected from infection by the resinous exudations 

 which quickly form over wounds. The "punk," or fruiting bodies, 

 of the fungus frequently occur near the place of attack, arid, for butt- 

 rotting fungi, are usually located on the lower half of the trunk. 

 The damage can be very largely controlled by eliminating the chief 

 cause — fire. In the more intensive management of small tracts of 

 timber, so far as possible the diseased trees should be felled. The 

 removal from the tree of the sporophores, or "punks," is of slight 

 temporary benefit only, since it stimulates the formation of new 

 fruiting bodies at other places on the tree. 



Sap stain, or "bluing" of the sapwood, generally agreed among 

 investigators to be the direct result of a fungus, is the most per- 

 ceptible and the most controllable form of fungous injury. The 

 reduction in value of stained lumber results in enormous annual 

 loss. Since moisture and heat are favorable to the development 

 and spread of the organism, the South suffers badly, but the pres- 

 ence of resin in the pines aids in checking the attack. In addition 

 to the usual method of rapid drying of the wood, experiments have 

 been conducted in chemically treating the wood of shortleaf pine 

 with a view of preventing attack from sap-stained fungi. 



WIND AND LIGHTNING. 



Over the greater part of its range, shortleaf is only slightly sus- 

 ceptible to wind damage. This is due to its deep root system and 

 its situation chiefly on the lighter, better-drained soils. Other aids 

 to protection against wind are its short leaves, slender branches, and 

 narrow crown. On the other hand, shortleaf is the only pine that 

 extends well into the tornado 1 region of the Middle Western States. 

 Here considerable damage is done every year, particularly in the 

 Ozark uplands of Missouri, Arkansas, and Oklahoma. Strips of 

 wind-thrown forest are present in all stages of recovery. After the 

 decay of the thrown timber these are easily recognized by the even- 

 aged stand, usually of pure pine, in the central area, with the two- 

 storied and high-forest condition in increasing degree toward the 

 margin of the cyclone strip. On account of its quick response to 

 light and the small size and abundance of its seed, the occurrence of 

 tornadoes has extensively aided the formation of pure, even-aged 



1 Known commonly p.^ "cyclone." 



