10 .lOURXAL OI' rORKSTRY 



in the nmlh indicates a Douglas fir site, in southern California a site 

 for the sister tree, the big cone spruce; an oak in the north indicates 

 the yellow pine-sugar pine association, in tlie south the same species 

 a site for the Coulter pine. 



Fire is recognized by all who have gone into the (juestion as the 

 agency responsible for the change in northern California from timber 

 to brush, but it has not been so recognized in the South, where, be- 

 cause of greater drought, the fires have been much more severe. Chap- 

 arral forest fires are exceedingly destructive to any forest trees which 

 may be in the stand because of the greater inflammability of the brush 

 and the height to which the flames reach, trees whose tops were more 

 than 50 feet above the level of the brush cover being killed. Exami- 

 nations of fire areas where trees have been killed show that only 6 

 per cent of trees 12 inches or over escape a chaparral fire, while 20 

 per cent of the trees under 10 inches diameter escape the ordinary 

 light ground fire in a forested area. What happens to these small 

 trees during a chaparral fire needs no comment. There is scarcely a 

 watershed on the Angeles and Cleveland Forests that does not show 

 evidence of fire-destroyed forest growth. In stands of brush where 

 growth studies of oak showed there had been no fire for more than 

 47 years were found numerous stubs of bigcone spruce and possibly 

 Coulter i)ine. On other areas where mountain residents of many years 

 standing declare positively that they do not recall seeing a single tree 

 in the brush slopes, evidences of a former bigcone spruce stand is 

 found. 



Of the conifers growing in the chaparral, three may be termed 

 strong species, for were it not for certain characteristics peculiar to 

 them there would be no tree growth in the chaparral at the present 

 time. These species are the bigcone spruce and the Coulter and knob- 

 cone pines. The former is a strong species because of its fire-resist- 

 ing qualities and the ability of the seed to lie dormant in the litter 

 without losing its vitality. Out of over 200 trees tallied on various 

 old burns. 19 per cent were not destroyed, while all other mature 

 conifers are killed by chaparral fires. Seeds sown in the litter from 

 one to five inches deep retained from 10 to 25 per cent of their vitality 

 at the expiration of two seasons, and the young seedlings are able to 

 withstand much shade, growing rapidly when released. Coulter pine 

 is classed as a strong species, for though the tree is readily destroyed 

 by fire, much seed is borne annually, the seed is of good vitality, and 

 when in the litter can withstand a light ground fire without severe 

 hurt. Seed is retained in unopened cones from one to five years on 



