In 2006, when I first started consulting with Hearst Castle about treating their sick oaks using fire mimicry methods, I was provided a set of photos, scanned and printed on a color copier, of several oaks around the castle grounds. I relocated these photos and have re-photographed them every year since 2006.
Presented here are photo comparisons showing these oaks on Dec. 14, 1995, Jan.4, 2006, and Jan. 4, 2013. During the period between 1995 and 2006, the oaks did not receive any fire mimicry treatments. In 2006 fire mimicry treatments began and have continued to the present. Note that the oaks generally show little change or show a decrease in canopy density between 1995 and 2006, and that canopy density has improved between 2006 and 2013 when fire mimicry treatments were implemented.
I realize that the 1995 photos are of poor quality, but they are all I have to work with. Still, I believe they provide some useful information about the positive effects of fire mimicry for oaks.