Do urban trees die sooner

[Corymbia]

Now do you honestly believe that the juvenile tree will mature when it has been allocated less than 10% of the land that the mature specimen would receive? Obviously not, and is part of the reason why urban trees
decline sooner.

I recently read these comments in a report on the Internet. I wonder how much truth there is in the comment that urban trees don't live as long ... what is the European experience?

A tree that made me think about this statement is the big old Eucalyptus in this picture. Soil compaction / roadway, buildings over roots, in a low rainfall area, lopped (topped), already well over 100 years old by this stage. Such abuse must surely shorten the life expectancy ... or does it?

 

[treeseer]

nice pic, but it sounds like th equote referenced trees with more severe constraints on rooting room. That said, root-shoot balance is key; look at bonsai!

 

[Corymbia]

Bonsai

nice pic, but it sounds like th equote referenced trees with more severe constraints on rooting room. That said, root-shoot balance is key; look at bonsai!

Bonsai is a good example! Does it shorten life expectancy (other than giving them to my wife ). I have seen some very old bonsai!

So is it that the life expecatancy is shortened by the site constraints or is it's size reduced by the site constraint as a result of needing to optimise the root - shoot balance?

 

[Urban Forester]

Most tree species don't have the genetic make-up to survive to their full forest life expectency when placed in the urban forest. Road salt, pollution and restricted root zones, combined with poor soil conditions that lack the "forest level" organic matter all contribute to shortened life spans. As with almost everything there are exceptions. Americas largest Burr Oak is about 6 miles north of me, located 50 feet from one of the busiest roads in the county. But for the most part, where I live, I always tell my clients that trees around here lose about 10% of their life span just because of the "conditions" they are planted in.

 

[derwoodii]

Sadly yes urban trees seem to have a much shorter life span. Predictable aliments of competition compaction & the car v tree impact will cause environmental stress related dysfunction. My experience with inner urban city trees is they never make it past 15 or 20 years. Some urban planner turns up to reinvent the landscape with his or the latest tree fad signature, pulls em all out replants with fashion statements then moves on.
Real loss is when the city meets the country. You get big old wood suffering at design maximizing $per square foot. Eg 200 - 300 red gums dying out just 5 year after new developments.

 

[Gunther274]

Yes as it has been said above, urban trees are put under high amounts of stresses. Its not than any one thing we do in urban settings are bad for the trees, its all the stuff combined, dirty air, salt, compaction, weed spray, simple competition with the green stuff we all love to cut and grow in our yards...ect.....

 

[ropensaddle]

I think it opposite but we have timber harvest here so the oldest and biggest trees are in urban areas. I can understand road salt you northern men endure but in urban areas here trees get watered in droughts helping them but then turf grass and other problems; I believe if it was not for forestry, trees in woods here may out last their city slicker brothers:monkey:

 

[Corymbia]

We certainly don't get the salt and we agree that stuff is just no good for most trees.(Move to a temperate climate) I wonder however how many things from the urban lifestyle add to the quality of life. Things such as irrigation , runoff, elimination of competition, disease control to name a few.

I understand derwoodii's comments about tree replacement in confined urban spaces but how about the tree in the normal back yard, particularly one that is planted. Why shouldn't it live as long as a normal forest tree. If the figure is 10% less and a normal forest tree gets to 300-400 years should that be a concern in urban planning? How about urban oaks in the UK, how have they performed, or exotics in the North East?

Here is a more recent photograph of the 1932 tree. Certainly it has more space than a normal street tree but much less than a backyard tree. I am guessing it is good for another 100 years or more.

 

[Urban Forester]

...a normal forest tree gets to 300-400 years should that be a concern in urban planning?

Very few, if any of the tree species I deal with have anything close to a 300 to 400 year life span. Most are in the 75 to 100 year range. Also the type of root system the tree produces plays a VERY large role in determining its survival.

 

[ATH]

soil chemistry is drastically different in the urban setting too - for example carbon is much higher (in most cases) in the forest than in the urban environment.

Elimination of competition? Where is that? Certainly not when turf is involved.

Urban trees are under more stress, and certainly have shorter lifespans. One tree does not establish a trend...

 

[ropensaddle]

soil chemistry is drastically different in the urban setting too - for example carbon is much higher (in most cases) in the forest than in the urban environment.

Elimination of competition? Where is that? Certainly not when turf is involved.

Urban trees are under more stress, and certainly have shorter lifespans. One tree does not establish a trend...

I can agree with that but I do know here the oldest trees are in yards. Forestry harvest is why! I know of a oak that was used as a hanging tree in Texas before and during the civil war!

 

[Corymbia]

I can agree with that but I do know here the oldest trees are in yards. Forestry harvest is why! I know of a oak that was used as a hanging tree in Texas before and during the civil war!

I likewise see lots of very old trees in urban environments. The Taxodium in Santa Maria de Tule is an example and I can give hundreds more.

Is it that we don't let trees get old or that they can't get old?

Is it that our perception of trees, tree age and tree potential is determined by our own relatively short life spans.

 

[ropensaddle]

I likewise see lots of very old trees in urban environments. The Taxodium in Santa Maria de Tule is an example and I can give hundreds more.

Is it that we don't let trees get old or that they can't get old?

Is it that our perception of trees, tree age and tree potential is determined by our own relatively short life spans.

Well I don't let em get too old lol Anything bigger than 55 inch dbh the grapple wont load so they come down:monkey: Nah just a little humor there:angel:

 

[S Mc]

Humor, perhaps, Rope. But a sad statement, IMHO.

That appears to be the philosophy of too many, if a tree gets big, it comes down. Our intolerance for large organisms is very distressing.

Be that as it may, harvesting of a crop (forestry) should not be taken into the equation when determining the natural life expectancy of trees. But if we take that out of the equation, we should also take out the removal of trees due to "make-overs" in our landscape.

And, I agree, one exception should not be used as an example of what does happen. We can all site the example of a tree that is surviving after numerous assaults and insults, be it topping, root pruning for sidewalks, black top installed over the root plate, severe compaction, impossible growing sites, etc. They defy everything we throw at them and keep surviving.

That should NOT be used as an example of what we CAN do to them.

You can even argue that many urban trees in private landscapes are killed with misplaced kindness as often as they are from abuse. In an effort to maintain them they are overwatered, overfertilized, overpruned to the point where they simply don't have the resources to keep fighting all the "good intentions" thrown at them. We often tell our clients, with trees many times "less is more".

To maximize the life expectancy of a tree? Plant a species appropriate to the site, maintain it in a manner that is conducive to ITS requirements (not just what may visually appeal to YOU), appropriate irrigation (not what the lawn or turf needs but what IT needs), etc.

Too many times people make selections and want instant results; trees should be chosen and planted for the long haul. If they have the capability of 300 to 400 years, then at least give that a modicum of thought. Give it a chance. Someone in the future will look back and be very grateful you did.

Sylvia

 

[ropensaddle]

Humor, perhaps, Rope. But a sad statement, IMHO.

That appears to be the philosophy of too many, if a tree gets big, it comes down. Our intolerance for large organisms is very distressing.

Be that as it may, harvesting of a crop (forestry) should not be taken into the equation when determining the natural life expectancy of trees. But if we take that out of the equation, we should also take out the removal of trees due to "make-overs" in our landscape.

And, I agree, one exception should not be used as an example of what does happen. We can all site the example of a tree that is surviving after numerous assaults and insults, be it topping, root pruning for sidewalks, black top installed over the root plate, severe compaction, impossible growing sites, etc. They defy everything we throw at them and keep surviving.

That should NOT be used as an example of what we CAN do to them.

You can even argue that many urban trees in private landscapes are killed with misplaced kindness as often as they are from abuse. In an effort to maintain them they are overwatered, overfertilized, overpruned to the point where they simply don't have the resources to keep fighting all the "good intentions" thrown at them. We often tell our clients, with trees many times "less is more".

To maximize the life expectancy of a tree? Plant a species appropriate to the site, maintain it in a manner that is conducive to ITS requirements (not just what may visually appeal to YOU), appropriate irrigation (not what the lawn or turf needs but what IT needs), etc.

Too many times people make selections and want instant results; trees should be chosen and planted for the long haul. If they have the capability of 300 to 400 years, then at least give that a modicum of thought. Give it a chance. Someone in the future will look back and be very grateful you did.

Sylvia

In a perfect world no one plants trees two inches from foundations or through roofs,under powerlines,in inadequate soils,too deep,with circling roots. Unfortunately no ones perfect. I however do believe me and many others can do better. The best thing is they are renewable and that is the perfection of life.

 

[Adara]

Estimate that approximately 39 million urban trees die annually. The sooner one gets started, the fewer trees are required. A empirical data, but do reveal the magnitude of the effect urban trees.

 

[jefflovstrom]

I likewise see lots of very old trees in urban environments. The Taxodium in Santa Maria de Tule is an example and I can give hundreds more.

Is it that we don't let trees get old or that they can't get old?

Is it that our perception of trees, tree age and tree potential is determined by our own relatively short life spans.

AH! Corymbia is the one guy to liven up our minds, (no offense),glad you are on a better subject. One I believe you already know the answer and waiting for some-one to come close to answering. I heard 1 million trees a year die in New York every year. ( Dog's peeing on new plantings), and Adam lived over 900 years, there is a bristlecone pine in the Sierra mountains closing in on 6000 years. You know, I saw Shigo in 1980 something and was stupid enough to sit in the front row. He was so passionate he spit when he talked. He said nowadays, trees are born into a hostile enviroment. I thought , so are we.
Jeff, CTSP

 

[Corymbia]

My hunch

I believe you already know the answer and waiting for some-one to come close to answering.

I am not sure I do know. The reality is I think that we all make hunches about the subject without support.

Certainly there are many inappropriate trees that are planted and then need to be removed but I also think that in the urban environment that there are many appropriate trees that are inappropriately removed.

What I do see is some trees that respond very well to urbanisation. Obviously pollution issues such as salt, urine, smog etc are negatives but not all urban trees are street trees or subject to such hostilities. Smog is rare now in much of the western world. The majority of urban trees are in domestic yards and green spaces. Now that we have finished (or nearly finished) our rape and pillage era and are becoming more environmentally aware how will our urban trees respond.

If I find an oak in the woods in England - is it likely to be performing better than a similar oak growing in a park in a major city? Because Australia and to some extent America are comparatively recent in terms of settlements our data is likely to be skewed but I see huge old ancient trees in Europe in urban environments. It is true that I don't see many but again is this a sign of past practices or a sign of the potential of trees in the urban environment.

I am inclined to think that our views are biased against the urban environment based on our past cultural practices and that in reality the urban environment is generally quite good for an appropriately selected tree in a suitably selected location. As I have already said, this is a hunch and I can't find sound research to support either argument - just conjecture such as this.

 

[treeseer]

I am not sure I do know. The reality is I think that we all make hunches about the subject without support.

Certainly there are many inappropriate trees that are planted and then need to be removed but I also think that in the urban environment that there are many appropriate trees that are inappropriately removed.

So true.

 

[jefflovstrom]

One's perception is One's reality.
Jeff