FIRES CAUSED BY LIGHTNING 



grazing has been undertaken this year 

 on six distinct areas. The local stock 

 owners who had previously used the 

 land under lease from the former own- 

 ers have readily accepted the change 

 of ownership and appear to be favor- 

 ably impressed with the methods em- 

 ployed by the Forest Service for graz- 

 ing purposes. While the number of all 

 animals authorized to graze upon these 



southern Appalachian forests is not 

 large, it is the belief of the forest offi- 

 cers in charge of them that under care- 

 ful supervision the lands will support 

 more stock than they have in the past 

 and that there will be considerable im- 

 provement in the individual animals, 

 with a constant increase in meat pro- 

 duction. 



FIRES CAUSED BY LIGHTNING 



EXHAUSTIVE inquiry has es- 

 l tablished the fact that lightning 

 ,j ranks next to railroads as a 



Forest 



rooted tree is a better conductor than 

 a shallow-rooted one, and a tree full 

 of sap, or wet with rain, is of course 

 a better conductor than a dry one. 



source of forest fires. 



officers say that the increasing care with Lightning sets fires by igniting the 



fire on the part of the railroads and the tree j tse if f particularly when it is dead, 



public generally tends to make light- or partly decayed and punky, or by ig- 



ning the largest single contributing niting the dry humus or duff at its 



cau ? e : base. The forest soil, when dried out, 



This statement represents a change { hes readi , because it ig made of 



of view from that held less than a { d d twi and k and 



decade ago in this country when for- 



est journals gravely argued whether 



r , / j r .-i, u -4. 



lightning caused forest fires, though it 



was known that trees were the objects 

 most often struck. Trees are said to 



be oftenest struck simply because they 

 are so numerous, and extending up- 



a smouldering fire for a con- 

 siderable period. It is probable that 

 most of the lightning-set fires start in 

 the duff. 



In the mountains of southern Cali- 

 fornia, Arizona, and New Mexico there 



, 



ward. they shorten the distance between are llkel y to be each y ear a number ot 



" 



the ground and the clouds ; further, 

 their branches in the air and roots well 

 into the earth invite electrical dis- 

 charges. 



While certain trees are said to invite 



electrical disturbances known as "dry 

 thunder storms." They come at the 

 end of the long dry season, and being 

 unaccompanied by rain, are very likely 

 to start many serious fires. For this 



lightning, and others to be immune reason the Forest Service has to keep 



from stroke, it seems to be a fact that up its maximum fire-fighting strength 



any kind of tree will be struck, and in those regions until the rains are fully 



the most numerous tree species in any established. In the plans and organiza- 



locality is the one most likely to suffer, tion for fire fighting the service aims 



Other things being equal, lightning particularly to catch these unprevent- 



seeks the tallest tree, or an isolated able lightning-set fires at the time they 



tree, or one on high ground. A deep- start. 



Planting 858,000 Trees 



More than 858,000 young trees are being set out this spring on national forests in L tab 

 and southern Idaho, and the season is reported as particularly favorable to their successful 

 growth. 



