Hazardous trees are a dilemma for all concerned.

Our shoreline neighbor Don Flora offers his comments regarding the hazards posed by trees. Dr. Flora was formerly employed by the United States Forest Service, where he headed watershed studies research, including stream biology, riparian ecology and related subjects.

All trees will fall.

The Question is when and in what direction.

• The tree will fall in the direction it leans.
• If not there, toward the side with branches.
• If not there, the way the wind blows.
• If not there, downhill.

For the arborist… An interior tree problem can be hard to detect until it affects the vigor of the tree, which can be too late. There are insect and disease problems whose specific causes can be obtuse, especially if more than one issue is present. And there are insects and diseases whose intensity and mobility are so great that we can do very little once they’ve settled in. Gypsy moths are a big threat along this line. So we shall probably have pest-invaded and pest killed trees about us, even in this affluent environment.

For the neighbor… A large tree looming or leaning across the fence is a risk. Period. All trees everywhere eventually fall; the uncertainty is when. What is the probability that the tree will fall this year? Within the life of my house? When we’re nestled in our beds directly beneath it?

For the owner… Regulations may preclude the removal of a tree deemed dangerous by the residents. The City’s solution is to require the intervention of an arborist. That’s fine until the arborist says the tree won’t fall and the owners think it will.

For the city… When the tree falls and kills two children in an upstairs bedroom, whose fault will it be?

Windthrow is erratic across the landscape.

The most common causes of fallen trees are not insect and disease but rather wind and saturated soil. These factors can be very local, depending on, say, blizzard-wind directions, soil stratigraphy, stormwater behavior, plus local snowfall patterns. Given that arborists cannot know the site-specific environmental conditions that actually cause the tree to fall, I’m sure no arborist feels infallible. Certainly foresters don’t.

Some years ago a number of trees blew down onto a Scenic Highway. People were hurt. Roadside trees were marked that seemed likely to blow over. Two years later the Forest Service found that many of the marked trees had indeed fallen, but so had many of the unmarked trees. The agency moved the tree line away from the highway.

A May 6, story in the Bainbridge Review said, “A large fir tree fell on a Honda Fit being driven on Battle Point Drive Tuesday evening, mangling the rear half of the vehicle. The Honda’s driver, an 18-year-old woman, was transported to Harrison Hospital as a precaution, according to Bainbridge Fire Department Operations Chief Luke Carpenter. There were no passengers…. Carpenter said that heavy rain and gusting winds likely uprooted the fir tree. According to a witness, the tree was about 130-feet long.”

When the City prohibits property owners from removing hazardous trees, who should be liable for the damage when they inevitably fall?