Southern California has been hit by a series of wildfires that have damaged thousands of acres. The fires have raged uncontrollably, fuelled by drought, high winds, and high temperatures. What is the long term effect to trees that are damaged by wildfires? If a tree has been burned and its leaves lost it may not mean it is dead. A number of the burned trees can and do recover. Many hardy southern California species are made to withstand wildfires that seem to be occurring on a regular basis.
The severity and the nature of the wildfire may determine the survival of a mature tree. For example, a fast moving smoldering fire without much intensity causes a tree to lose leaves but typically revives in subsequent seasons. A very hot fire and that rages uncontrollably over a period of days can leave the trees completely scorched beyond recovery. The trees primary defense against fire is the bark. A careful examination of the bark can determine if the tissue below it has been harmed. As the bark is peeled back, a moist layer is sometimes evident. If it is white, pink of green it may indicate the tree is viable. However, if the tree trunk below is orange or brown that is not a good sign. The tree may not be able to survive.
When significant portions of the trunk are damaged it is likely that the tree could be attacked by insects and diseases. Small or new trees may be more susceptible to wildfire damage than larger more mature trees. If the roots are compromised, the tree may become unstable.
Fire scorched trees may look unusual and may be an eyesore but if you are willing to wait these trees can often return and recover. A certified arborist can be provide recommendations and help determine which trees will survive and develop recovery plans. The roots will benefit by placing mulch over the soil. Delay pruning these fire damaged trees except for removing dead wood for safety reasons. Always remember trees react slowly because they are resilient.
Article originally written Santa Cruz Sentinel July 2008