Tom's Blog

Wednesday, July 31, 2019

Surprising resilience of a black walnut tree

As I discussed in a 2017 post, black walnut (Juglans niger) is one of the bad guys in oak savanna restoration.

As that post also discussed, walnut trees are fairly difficult to eradicate permanently. Recently, Kathie and I have found a good example of this (see photo below).

This greatly deformed tree is close to what we call the “Circle Prairie”, a small mostly remnant prairie that I have    discussed in detail in the post linked here. 

There was a large walnut tree formerly in the middle of the Circle Prairie. It was removed in the winter of 2015-2016. To get rid of the substantial amount of wood (small branches, limbs, and trunk), the tree was cut up and piled adjacent to another walnut tree, the one shown in the photo here. There was a lot of wood, and a large pile was built. When the pile was finished, just before starting the fire, one of the crew climbed to the top of the burn pile and lopped off the main trunk of the tree being used as an anchor. (The intention was to also throw the wood of the anchor tree on the burn pile.)

The roaring fire of this burn pile was tended and consolidated in our usual manner. The intention was when we were finished to end up with only ashes. Unfortunately, the crew ran out of time and the anchor tree, topped and coal black, remained as a ghost.

Fast forward to July 25, 2019. Kathie was doing some weeding in the Circle Prairie and noticed the strange tree shown in the photo. The tree is growing vigorously with several large leafy branches. The trunk is pitch black, attesting that it was this tree that participated in the burn pile of 2 ½ years ago.

Explanation? Probably because of the cold weather when the burning took place, some dormant buds near the top of the tree survived the fire and resprouted. But how did the cambium survive that very hot fire, attested to by its black trunk? Presumably the temperature did not get hot enough on the side of the trunk away from the fire.

We have plans to remove this outlandish tree sometime next winter.