I'm fallin'

When discussing tree risk assessments we talk about looking for signs a tree is likely to fail.  The following pictures are of a white oak that some may argue is in the process of failure.  Let's take a look....

As we approach the tree, notice first the lean. What this picture doesn't show is the residence within 50ft of the tree's base.

Soil heaving, especially on the side of the tree opposite the lean, is pronounced.

Here we can see where large roots are separating from the soil.

Another image of large roots separating from the soil, and some resulting voids in the soil.

After discussing these issues with the client I discovered that 5 years ago this white oak was on the edge of a wooded area that had been cleared to make room for a new home lot.  This tree had spent most of its existence to this point with mature neighboring trees protecting it from wind and storm events on the side opposite of where it is now leaning.

By altering this tree's environment, a tree that may have lasted for years to come was turned in to a tree that is now at an extremely high risk for failure.

Not to Kick You when You're Down, but another Incredible Tree Failure

I always hate seeing a tree fall, but sometimes there is no better way to learn about the way trees grow than from a post failure forensic investigation.  And while I know our last post was about a fantastic large tree failure, this was too good to pass up.

Our subject is a large mature willow oak that suffered a tremendous root plate failure.  This tree was growing in a known flood plain, and was one of the tallest trees on the block.

Notice the amount of standing water in hole left behind when the roots pulled from the soil.  Keeping the size of the root plate in mind, and the proximity to the camellia in the picture below, notice how the wet conditions allowed the roots to be pulled from underneath soil like a magician pulling the table cloth from a fully set table.

The only indication of decay at time of failure was a cavity along the lower trunk/root flare of the tree.

Now, here is a part of the tree we don't get to see often.  With the root flare up ended we can see the structure and arrangement of the structural root system, and associated decay.

The decay column moving upward in to the stem is a common occurrence in many tree species.  It is a result of the original tap root dying off and allowing a path for decay to move into the stem.  This is a process that can take years, if not decades.  In species that compartmentalize well it is just a peripheral event, but for poor compartmentalizers, it may the defining defect in their demise.

Good thing the Jeep was insured.