398 THE RELATION OF FORESTS AND FOREST FIRES 



other to assure the continuance of the species, with little regard 

 for the single tree. An example of the first kind is the western 

 larch, whose enormously thick bark is almost fireproof, and so 

 good a non-conductor that it protects the living tissue beneath 

 it even against fires hot enough to scorch the trunk 50 or 75 feet 

 above the ground. It is to this quality of their bark, as well as 

 to their marvelous vitality, that the big trees of California owe 

 their power to reach an age of 3,000 or 4,000 years. The east- 

 ern pitch pine protects itself in the same way. So do many other 

 trees, including the longleaf pine, which adds to this quality of 

 its bark another method of protection that places it at the head 

 of all the trees of my acquaintance in its capacity to resist fire. 



Almost all trees yield readily to slight surface fires during 

 the first ten or fifteen years of their life. To this statement the 

 longleaf pine is a conspicuous and rare exception. Not only do 

 the young trees protect themselves in early youth by bark which 

 is not uncommonly as thick as the wood (the whole diameter 

 being thus "two-thirds bark and one-third wood), but they add 

 to this unusual armor a device specially adapted for their safety 

 when growing amid long grass, usually a most fatal neighbor to 

 young trees in case of fire. It is to be noted that the vast ma- 

 jority of longleaf pines are associated with grass from the begin- 

 ning to the end of their lives. During the first four or five years 

 the longleaf seedling reaches a height of but four or five inches 

 above the ground. It has generally been erroneously assumed 

 that this slow growth made it specially susceptible to injury 

 from fire ; but while the stem during these early years makes little 

 progress, the long needles shoot up and bend over in a green 

 cascade which falls to the ground in a circle about the seedling. 

 Not only does this barrier of green needles itself burn only 

 with difficulty, but it shades out the grass around the young 

 stem, and so prepares a double fire-resisting shield about the 

 vitals of the young tree. Such facts explain why the fire which 

 has restricted the spread of evergreen oaks in parts of Florida, 

 for example, has made a pure forest of pines in a region where 

 the reproduction of the oaks is phenomenally rapid wherever 

 the annual fires cannot run. 



The second method of protection against fire is that which 

 sacrifices the individual but secures the safety of the species. 

 Perhaps the most striking example of this method is furnished 

 by the lodgepole pine, which is being distributed over hundreds 



