Oak Wilt – Dead Woods Walking

Shortly after we had taken charge of our 44 acres, I asked my husband what was his favorite thing about our land.  Doug said, “That young red oak across from the house site.”  I knew immediately which one he meant.

It was about 15 years old — a robust, teenage tree maybe 20 feet tall, vibrant and full.  It was a joy to behold.  It was a monument to the promise of life. In fall, its leaves had turned a luminous barn red that just made you smile to see it.

The next year, in the middle of a gorgeous August, every leaf on that tree turned paper bag brown.  It was dead, and we were horrified to realize that other, older oaks in the woods on our hill had dying branches.

...Oak wilt on the edge of our woods.

...Oak wilt strikes on the edge of our woods.

The arborist diagnosed oak wilt.  Learn more here and here.

Oak wilt occurs when a fungus, Ceratocystis fagacearu, gets into a tree’s tubing and plugs up its water-conducting vessels.  An infected tree can’t get water from its roots to its leaves, and it doesn’t take the leaves long to die.  The tree is a gonner.

Oak with wilt and healthy (for the moment) neighbor.

..Earlier this summer, an oak with wilt on right and (for the moment) healthy neighbor.

And this nasty stuff spreads very efficiently.  If oaks of the same species have roots that touch, they often grow together, so the fungus will move easily into the neighboring tree and from there to the next and the next – like underground dominoes.

Nitidulid-beetles,-which-spread oak wilt.  (photo credit USDA)

...Nitidulid beetles, which spread oak wilt. (photo credit USDA)

Or it can spread through the air.  Within a year after a tree dies, the fungus can produce spore mats under the tree’s bark.  These mats give off a compelling, fruity smell that certain beetles love.  They will tank up on the stuff and fly to another tree.  If they land on a place where the tree has been cut or broken, then the fungus moves in, and if that tree is touching its neighbor’s roots, it becomes a new epicenter of oak death.

It looked grim.  When I learned what was going on, I was frantic.  I was despairing.  But we quickly switched to battle mode.

There was nothing to be done for infected trees, but we could try to interrupt the domino effect.  We could trench and cut the roots.  That took a lot of study.  Infected trees might already have spread fungus to their neighbors, so we had to look at healthy trees and calculate how far their roots where spreading, and then trench beyond them.

Marked for removal.  We should have been tougher.

...Marked for removal after we trenched. We should have been tougher.

The advice was to cut all the trees within the circle of potential infection, but we had a resistance to cutting seemingly healthy trees that we could not overcome.  We left the outer ring closest to the trench line and hoped they might be spared.  (We have become harder since then.)

The silver lining was that this “pocket” of oak wilt had occurred in the very spot where we expected to build.  Because our land is so hilly, there are very few spots that are ideal for the best solar gain.  We wanted to build on fairly steep land to save the more level land for potential agricultural use, but we couldn’t build where it was too steep, or we would not get a driveway permit.  (After all, the township might need to get a fire truck in there someday.)

We took some comfort in the fact that Mother Nature was clearing a spot for our house.   But, enough is enough, Mom!

Cut to the chase.  Either by root or beetle, the wilt has jumped our trench.  It may yet take every Red Oak on the hill, and most of the oaks on the hill are Red.

Doug labels a promising young White Oak.

...Doug labels a promising youg White Oak.

I did despair.  But I’ve moved on.  Now we are focusing on what will follow these oaks. They are way too crowded for their own good growth anyway (probably accentuating the root spread issue).  What will be left will be a more savanna-like setting in our lifetime, but we can take good care of the trees that survive.  There are a handful of lovely young sugar maples crouching in there, beneath the oak canopy and there is also a smattering of White Oaks.  White Oaks have a better survival record against wilt.

This fall we have gone through the area, looking for little seedlings that we can protect and encourage.  At first that involves just not stepping on them, so we are tying orange tape to them before they become just one of thousands of twigs on the forest floor.

Then we will be protecting their buds from deer browse, and in a few years, their young sapling trunks will need to be protected from buck rub.

Then they will be on their way.  Reaching above our heads and doing their tree thing.

It’s succession.  Although, succession is now being affected by the new kid on the block — climate change (see my post The Heat is On)

I’m starting to understand succession and learning to accept it.   It happens in royalty, and it happens in nature.

...Hope for the future.

...Hope for the future!

The woods is dead.  Long live the woods.

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