Eversource arborist explains roadside tree removal

One of several trees on Sandy Pond Road that’s been marked for removal.

Residents may have noticed temporary signs attached to numerous roadside trees in town that are being targeted for removal by Eversource. The town is required to hold a public hearing to invite comments or objections to removal of specific trees; it will take place on Wednesday, May 22 at 7 p.m. at the DPW office (30 Lewis St.). Anyone who can’t attend may email or call DPW Superintendent Chris Bibbo at bibboc@lincolntown.org or 781-259-8999 (he will read aloud the emailed comments at the hearing).

The Lincoln Squirrel asked Eversource Arborist Matthew Mitchell some questions about this process; here are his answers.

Why has Eversource not done this in Lincoln in several years?

A few aspects to this question. Our tree program is two-pronged; we have a trimming program and a removal program. The trimming program maintains space around the primary wires at the top of the electric poles, usually as close to 10 feet to the sides and bottom and 15 feet above as we can while following safety regulations and proper pruning practices. This program prunes each circuit every four to five years. There are several circuits in Lincoln that get pruned in different years, with a large Lincoln circuit having been pruned just last year. So we are around town regularly, even if the trimming work isn’t as dramatic as outright tree removal.

Our removal program is not cyclical and is a little more subjective. Circuits with recently poor outage rates are targeted, but we also try to do removal work on circuits that aren’t getting outages yet but in my opinion have a strong potential to see a spike in the future. We want to be removing potentially hazardous trees before they cause outages or cause a danger to general public safety. If I do my job correctly, nobody will have known there was a possible issue at all.

It has been a while since we have removed public trees in Lincoln, but last year we were fairly active in town removing hazard trees on private property. The motivation for this project happening now is that I think the Lincoln forest is aging out of a young forest into a more middle-aged one, and part of that process involves trees accumulating injuries or poor structure that make overall failure more likely. Tree injury, mortality, or failure is a natural part of the forest life cycle, and it is all well and good when it happens in the middle of the woods, but when these trees are situated next to power lines, sidewalks, and homes then human action is needed to intervene and prevent them from interrupting the power we depend on or causing property or bodily injury.

A specific issue in the Lincoln forest is that in the last few years, Lincoln has lost the majority of its ashes to emerald ash borer (EAB). This bug is an invasive species from eastern Asia and because our native ashes did not evolve alongside it, they do not have the evolutionary adaptations of Asian ashes. The beetle causes a near 100% fatality rate in native ash in any locality it has been introduced, and it is why when you go camping you will often see signage asking campers to not bring off-site wood for campfires as this is the beetle’s main avenue of spreading. Other than expensive pesticide treatments on individual large and significant trees, the only cure for EAB is preventing it from arriving. Ashes with EAB make up the single most common species on our Lincoln removal list.

What are the criteria for selecting trees to remove?

Circuits are profiled by our certified arborists to assess trees along the power lines for removal and then reviewed and edited by myself. Obviously, dead standing trees are immediately added. When the tree is still alive, it is visually assessed from root to shoot for signs of stress, poor stem structure that makes failure more likely, open or hidden rot cavities that could be a breakage point, the presence of tree pests that pose significant risk to the tree’s survival such as EAB (but there are others that affect more than just ashes), and overall form and vigor. The majority of non-undergrowth, larger diameter trees on the list are on there because I believe they are likely to fail in the short to mid term future and I would like to get them removed before they do.

I specified size in that last point because a lot of the trees on this list are small undergrowth trees. They are healthy in and of themselves, but they have been selected for removal because they are of a species that have characteristics that make them unsuitable to be located under the wires. Cherries and elms are the two most common. These species grow faster than average, sprout aggressively when they are pruned, and usually do not take to being pruned to grow out and around the wires but stubbornly keep trying to grow straight upwards. These trees are difficult for our pruning program to control and even when pruned to arboriculturally correct and healthy standards are frankly an eyesore. It is more effective to have them removed outright as well as improving the aesthetic of the roadway.

There is a small handful of healthy, moderately sized trees on the list that do not have significant biological or structural defects. They are on there because they are actively touching our primary lines which carry thousands of volts. If/when friction wears away the wire coating, these trees will cause an outage by catching fire themselves and potentially (although very unlikely) acting as an electrical conductor for anyone who happens to be touching the tree.

What’s the timeframe for removal?

It depends on the contractor’s workload from other areas Eversource services, but I expect work to begin a few weeks after the tree hearing

What happens to all the wood?

The logs will usually linger for a week or two as the log crew is a separate crew to the removal crew. Because the trees we are targeting are often unhealthy to begin with, there is not much value in their lumber. Usually they are given to facilities that process them into chips for resale or industrial use, sometimes the town wants the wood themselves for whatever reason. It depends on each of our contractor’s individual system and geographical location, and it is not a part of the process I am much involved in.

If any abutters to trees being removed would like to keep the logs themselves or if they want chips for organic mulch, that is also an option if they let us know. Chips are measured by the truckload or so, if anyone wants them they usually need to have a full-sized garden or several yard trees.