Large dead top doug firs.

In older growth doug firs, there is sometimes a dead standing top. At work, we have to manage hazards in campgrounds/ public access areas.

My co-worker tells me that he heard from some arborists at a conference that if the tops are punky, removing them is okay/less detrimental than if the tops are grey and "hardened". He said that leaving those hard, gray tops in place was better for the tree than removing it.

He said that there have been 2 large doug firs at parks that have had dead tops removed that died relatively soon afterward, out of a handful still alive after topping the dead leaders.

One thing to consider is that the 2 that died could have been dying anyway.


I've seen several around town these last two years with dead tops, maybe 20' to 30', on 130' trees. Saw one while I was driving home tonight. Been topped of the deadwood. Don't know if they cut into the live trunk or not. Several newly dead branches just below the top of the stem/ topping cut.

Tomorrow or later this week, we will have a dead top to remove from a 4' ish dbh Dfir.

Anybody know anything about this?

I don't have anything to tell you but it sounds like an interesting theory. I would think it would have a lot to do with why the top died. I would expect that the hard, silvery tops died back due to drought or water stress and that the soft tops died back from some sort of insect attack but I am just guessing. I wonder if Burnham has any thoughts on the matter?

Seems like cutting as high as possible might be better than just above live wood, and least favorable would be cutting anything live. Mitigate the risk quite substantially, while trying to work with the tree, and minding the climber's safety.

This week's park fir and the one I saw driving home today are otherwise healthy. The park one is in a laminated root disease pocket, but looks good, surprisingly. I wonder if you can see the root disease pocket in aerial photos.

I would think that the gray top sounds like drought stress. I've heard of water columns breaking, but don't know what that means exactly on a biological/ physiological/ botanological level. Yes, botanological is a made-up word.

I can't imagine that removing anything already dead would cause the tree to die. That said, the theory of whether or not its better to leave or remove, on a long term scale, is interesting.

As to the water columns, the water molecules are connected with positive and negative charges. Transpiration releases water and stretches the column like a bungee. If there is no water to pull up....

I wonder if it as simple as the climber goes up to remove the dead top, is not comfortable going all the way to the dead, makes a large diameter topping cut in the green. The tree is clearly stressed for one reason or another and cannot handle the added stress of a large topping wound.

I don't know, but I was wondering along the lines Dave just mentioned. Might be a case of too many variables to make a blanket statement of which is better.

I do think that a hard, dead spike top will shed water and allow little to gather and possibly enter the interior of the tree, which might not be the case with a topped tree.

Some species, like western larch and western red cedar, will hold a solid spike top for many decades with no softening at all. Doug fir is not as good at that, but better than some others, like any of the true firs.

There might also be an environmental variable involved here as well. When dead wood in Doug firs becomes hard and gray rather than punky, it often indicates a very low population of decay causing organisms and a drier environment. If dead wood is punky and rotten, this is usually in a very moist environment, which can support a much larger population of decay-causing critters. This would mean the trees with rotten punky tops would more likely to die because they exist in conditions that promote decay, not because the dead top was removed. I see this a lot in trees over in Yakima, where it is extremely dry. Dead branches and tops take a really long time to get punky because the environmental conditions are not favorable for most decay-causing organisms, which also means that trees survive horrible pruning a lot more often.

Good point, Sean.