Death of an Oak

This beautiful old oak tree was struck by lightning last September. Within 2 days, it had completely wilted and showed no signs of life. Sudden death due to lightning is uncommon in trees, especially after the end of the growing season. Several experts recommended leaving the tree until spring to see if it showed any signs of recovery. Sadly, the tree did not leaf out this spring. Because the tree is in a public park next to a popular basketball court, it had to be removed promptly. The photos below show the tree before and after death and the process of removing it.  We have collected a section of the trunk and will use it to determine the tree's age.

Before it was hit by lightning, this was a remarkably vigorous tree with no signs of death or decline. Within days after being struck, the leaves had wilted, twigs were dead and the fungus Biscogniauxia atropunctata had popped out on the major branches.  Biscogniauxia is an endophytic fungus, living quietly within the bark of healthy trees and fruiting rapidly when the tree is stressed.

bur oak tree
The tree before being hit by lightning.

Felled tree
The tree after felling

Section of a tree
Section of the tree for ring counting

Lightning struck tree
The tree three days after it was struck by lightning

Slicing the tree to count rings
Slicing the tree to count rings

Fungus on a log
The gray material is the fungus Biscognauxia atropunctata