Should these trees be removed?

[Ekka]

Stumper

What you have described is crown reduction. And although done carefully and correctly it is not the preferred option. We studied some beautiful work done by meticulous aborists on mature trees, they obviously used a boom truck .... the tree did not recover as well as thinning and some of the really mature trees died ... 6 years later.

We do quite a bit of thinning on our eucs here, a common thing.

Thinning does not involve the reduction of height or spread nor the removal of interior branches to the point of there being none. Imagine following the branch from the trunk union and selectively removing a tributary along the way to the tip and one at the tip. Leaders are left intact.

I'll try and get a pic going, I'll need to scan it etc.

 

[treeseer]

We do quite a bit of thinning on our eucs here, a common thing.

Eucs and oaks are very different.

Justin did a good job defining the fuzzy area where cuts are both thinning and reduction. Reduction cuts can be overdone but so can thinning cuts. but I'd rather weaken a tree or branch with a big dose of pruning than leave heavy, imbalanced ends that are a high risk to break.

There is no reason to avoid shortening a branch if dose, species, condition. location etc are all considered carefully.

Do you get ice sorms in AU?

 

[Old Monkey]

In California eucs are hard to kill. People hack on them year after year, taking all their foliage off sometimes and still they come back. I know there is a beetle that kills them that came over with them and fire can do a number on them but crown reduction?

 

[Ekka]

Here's a pic of crown thinning.

Where I live we don't get snow etc but they do down south and there's loads of eucs plus other species we don't have here.

The test trees this guy had were Ash and Birch, the test area was in England.

 

[treeseer]

Nice picture; that's a heavy dose of pruning, way ove r20%, but maybe tolerable in a young tree of a vigorous species, if done to mitigate defects.

Generally I'd avoid taking off that much.

Some of those cuts are raising cuts and some are reduction/thinning cuts because they shorten branches and reduce the general outline of the crown.

What test trees are you talking about?

 

[Kneejerk Bombas]

I ask again, what did that thinning do to the tree other than take away resources, cause multiple injuries, damage the natural form, make it more attractive to insects, and cost the owner a pocket full of cash?

 

[a_lopa]

i thinned a paulownia a few months back at owners request,that night a good wind came thru and took half the top out LOL thinningis ok with crowding trees just.not one tree on its own IMO.although as mike points out the benifits $$$arnt to bad we think were doing good get some $$$and goodbye.i can only think of a few people that can actually do it properly.

 

[Kneejerk Bombas]

Storm damage on thinned trees is very common. Thinning exposes branches to wind from directions that push branches in directions they are not designed to encounter, and have not encountered before.

 

[Shespen]

Good thread!
I can see everyones point of veiw depending on what species of tree they are working on and I can disagree with everyone for the same reason. Looking at Ekka's little jpg I think of an oak and I would have to agree with Mike Maas that you have just done the tree a grave disservice and probably killed it. On the other hand if that were a maple then I would say that you have eliminated competing branches that are competing for the same sunlight and have induced lateral growth. In both cases I am refering to juvinile trees. If these were mature trees then I would think that you have done more harm than good in both cases.
Seldom would I "thin" a whole tree for any reason. The reason that I would thin a tree or branch would be to promote lateral growth of dominant leaders by eliminating the competition for sunlight. Usually this is a case of reconstruction of a hacked limb or whole tree that now consists of a multitude of epicormics and it is a process that is done over time. I have found that thinning for weight reduction generally doesn't work and just weakens the structural integrity of the branch further by inflicting a wound that needs resources to wall off the wound and at the same time reducing the source of those resources. Thinning to reduce wind "sail" doesn't work for reasons that Mike postulated on his 4/12 post. Thinning a Japonese Maple or a locust has the opposite effect no matter what the justification. Thinning to open the crown so a clients lawn can receive more sunlight should only be done if the only option is tree removal. We don't have eucs here so I can't speak for them. I am just wondering why crown thinning is a common practice on them? Getting back to the original post... I would definately remove these maples for safety reasons. They are a lost cause and trying to save them would just be throwing good money after bad. Use your money to go buy the appropriate tree species for that location and replant.