Responses of Big Sur oaks to fire mimicry followed by wildfire

25 02 2022

In February of 2019 I began photo documentation of 21 coast live oaks in Big Sur, CA. At least six of these appear to be “Ancestor” oaks, culturally-modified by the Esselen Indians via pollarding of their canopies. All oaks were initially treated with a fire mimicry protocol (clearing, pruning, moss/lichen removal, soil fertilization, & limewash), with the intention that this work would improve the survival rates of the oaks, whether or not a wildfire occurred. The first year results were About photo documented in February 2020. In August 2020 a severe wildfire was ignited in the area and burned through all the groves of the treated oaks.

Yesterday I was finally able to access the site to observe and photo document the findings. Both wooden structures on the property were lost, as were two treated oaks that grew adjacent to them. However, of the 21 oaks initially surveyed, 17 survived the fire, a survival rate of just over 80%. Four of the six “Ancestor” oaks also survived. More than 75% of the oaks showed noticeable signs of improvement in canopy lushness following fire mimicry. A year and a half after the wildfire, 6 of the surviving oaks continue to show signs of heavy fire damage in their canopies. However, 11 (or just over 50%) of the surviving oaks are showing significant improvement of their canopy health following the wildfire.

These are exciting results (see photos below) and show to me that fire mimicry treatments can provide considerable benefit to survivability and health of oaks and other trees in the event of a wildfire.

Read the rest of this entry »