113 



The second undesirable effect is the relatively rapid change in 

 forest structure and conqjosition. Species such as white fir 

 are able to grow in the shade of the sequoias and, in addition 

 to providing a "ladder" for fires to follow into the crown of 

 the sequoias, greatly increase con^jetition for *ra.ter and soil 

 nutrients on the site. The stress from this conpetition often 

 results in insect and (lisease epidemics. 



We know of no •el«ntlf ically valid ai^eriawital studies or data 

 on fir« ecology that muppoTta the conclusion that setting aside 

 the groves can preserve them over time In the face of current 

 levels of fuel bulldx^ and natural successlonal processes. 



Two methods are availedsle- to reduce unnaturally high fuel 

 buildups : prescribed burning and direct removal of understory 

 vegetation by thinning. Using only prescribed fire as a fuel 

 reduction method has been used in groves in National Parks but, 

 although a somewhat effective tool, does entail more risk thsm 

 a ccmbination of these methods. Understory thinning to reduce 

 fuel loads axid risk from insects and disease has also proven 

 effective where carefully prepared and executed. 



In many of the giant sequoia stands, suppression of natural 

 fires has resulted in invading 70 to 80 year old white fir 

 which now provide continuous fuel "ladders" from the ground 

 into the crowns of giant sequoias. Because of this, prescribed 



