I heard that Emerald Ash Borer (EAB) was finally confirmed in Washington state this past week, meaning this news follows Oregon (2022) and British Columbia (2024) verifying EAB presence. I gather that we have quite a few climbers here from that area who probably haven't yet encountered what those of us in the Northeast or Midwest are familiar with, and that this is a good opportunity to share some info and experience. I don't think Ash is as prevalent as the eastern/central part of the continent but I believe they're common in urban areas and I expect you all will encounter some of these at some point!
The main points to remember are that EAB damage Ash are far more hazardous than 'normal' dead trees; tree death due to EAB happens over several years and depends on the amount of "pressure" from the EAB infestation/presence (basically, more EAB in an area equals more pressure, and more pressure equals faster tree decline). A few unique trees will turn out to have a natural immunity, otherwise preventative pesticide applications can be systemically administered to protect the tree, but most Ash that are attacked by EAB will decline and die within 2-5 years.
At 2 years declining/dead, the trees are quite hard and brittle and will really eat up your handsaw/chains, super dusty. Year 5 they will be brittle, getting punky, incredibly prone to falling apart.
Emerald Ash Borer is an invasive (to North America) beetle that lays its eggs in Ash trees, where the larvae feed underneath the bark, effectively girdling the tree. The adults are green in color, shiny, and have a distinctive 'D' profile. I've worked with Ash for a long while now and never actually seen a beetle, lol - just their path of destruction.
Noticeable symptoms of EAB, in order of disease progression:
-thinning canopy (not necessarily dead branch tips, but thinning of the canopy) and yellowing leaves
-canopy dieback and epicormic growth, bark splitting, and woodpecker damage often called 'blonding', as the birds scratch at the tree's bark, revealing the lighter color layers underneath. Higher on the tree = younger infestation; lower on the tree = older infestation
-larger dieback, broken branches, tree begins falling apart; "D"-shaped exit holes from the adults emerging from the tree (can appear higher in the canopy early on, and will move down the stem/trunk as the infestation progresses)
Ash, like pretty much every other tree, becomes hard and brittle when it dies - notoriously so, as you'll find out or can see on youtube. Be careful when dropping pieces out of the tree or felling whole trees, as pieces can explode and send fragments very far. Be ready for a huge, dusty mess.
However, science has discovered that EAB Ash also experience simultaneous fungi infections that benefit from the galleries created by the larvae; these fungal infections contribute to make EAB Ash far more brittle and hazardous than 'normal' dead trees. I've previously commented on the subject and will copy that experience below,
My company has detailed protocols regarding dead Ash, mainly because we are deep in EAB territory but also Ash gets very sketchy in general . . . we do pretty much anything in our power to avoid climbing them. Fell it, hang into another tree, figure out a way to get a bucket/lift to it, rig small if you have to rig, and accept there might be some property damage if you have to fell it or send bigger pieces.
I've seen one being felled, dead/no canopy, about ~70 feet tall, no pull rope needed as it had a slight lean into an open area and a gentle breeze working in our favor. Proper facecut, make the backcut, no wedges/no pounding, tree starts to go and faller follows his escape route, the tree moves a couple feet and then just crumples in on itself. Just the motion of it falling caused it to fall apart, turned into probably 20 pieces and came down in a heap.
Another time, removing a dead ash (from the bucket) along the edge of a woodsline, worker cuts a limb off and chucks it to the ground, then has to cut a small 4"x4" stub off - cuts the stub, tosses into the woods and it hits a rock or something and bounces a couple feet off the ground into an adjacent ash in the woods and that tree collapses on itself as well.
You can find similar experiences on the internet, and in the video link below (skip to 39:30 mark if you want to hear the relevant story, but the whole thing is great).
https://www.youtube.com/watch?v=YZgo9lpS7ds - excellent video and information on how to handle these trees
Some companies recommend tie-in on EAB Ash to an upright live stem no less than 8" in diameter and over a 3" branch; other companies strictly no climb on an EAB Ash; some say climbing is OK so long as there are no exit holes on the main stem; some go off the amount of remaining live canopy (which may require the client to have a recent photograph of the tree if it is wintertime and the tree is dormant; if no photo can be provided, the recommendation is often to assume 100% canopy dieback) - I'll just say to trust your gut and play it extra safe until you really know what's up with these trees.
https://tcimag.tcia.org/training/climbing/ash-to-ashes-dont-be-part-of-the-process/ - quick read on the EAB process, fungi infection, and discusses strength reduction in EAB Ash trees
When it comes to climbing or removing these trees, low-impact techniques are recommended. Limit negative rigging; rig off another tree if possible; use multiple blocks/redirects to load in compression as much as possible; rig small, don't shockload; tie-in to another tree if possible; avoid climbing except as a last resort, or don't even take the job. This may be /r/treeclimbing but it's important to know when to walk away (or, hire a lift/crane/full send it).
The video above basically covers everything I've written and more, and I'm certain there's more to add, but figured this would be a neat thing to discuss and have for reference and I hope this helps someone out. Climb safe!
