# Do urban trees die sooner



## Corymbia (Apr 25, 2010)

> 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 (Apr 25, 2010)

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 (Apr 25, 2010)

*Bonsai*



treeseer said:


> 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 (Apr 25, 2010)

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 (Apr 25, 2010)

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 (Apr 26, 2010)

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 (Apr 26, 2010)

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 (Apr 26, 2010)

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 (Apr 26, 2010)

Corymbia said:


> ...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 (Apr 26, 2010)

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 (Apr 26, 2010)

ATH said:


> 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 (Apr 28, 2010)

ropensaddle said:


> 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 (Apr 28, 2010)

Corymbia said:


> 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 (Apr 28, 2010)

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 (Apr 28, 2010)

S Mc said:


> 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.
> 
> ...



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 (May 7, 2010)

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 (May 10, 2010)

Corymbia said:


> 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 (May 15, 2010)

*My hunch*



jefflovstrom said:


> 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 (May 15, 2010)

Corymbia said:


> 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 (May 15, 2010)

One's perception is One's reality.
Jeff


----------



## ATH (May 15, 2010)

Corymbia said:


> ............ut 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..........


Besides pollutants, don't forget the treatment of soils. Past practices were ABSOLUTELY less stressful to trees than today's. Scraper pans didn't exist 100 years ago, let alone people dumb enough to buy top soil in a plastic bag at WalMart (not that I would ever do that  ), so top soil was left in tact. Around here (heavily agricultural area), in preparation for development they scrape the "top soil", but the real top soil has probably been gone for decades. Then they dig a basement with equipment that is so heavy squeezes all of the pore space out of the soil. That dirt from the hole is spread across the surface because it doesn't pay to bring it off site (there is nobody dumb enough to buy that clay). Now lets plant turf and put a tree in the middle of it. What about that is NOT stressful for a tree?

(Did I mention the time we found burried shingles? The homeowner wondered why he had a wet spot in the yard...)


----------



## Corymbia (May 16, 2010)

Ok so perhaps there are still some really bad practices out there, particularly at the planting stage (although we should be starting to see some changes). Once the tree is growing where does it stannd?


----------



## ATH (May 16, 2010)

Corymbia said:


> Ok so perhaps there are still some really bad practices out there, particularly at the planting stage (although we should be starting to see some changes). Once the tree is growing where does it stannd?


In crappy soil

Soil restoration is a LONG process - probably at least a full generation of trees (not people), maybe 2 tree generations.

If we can manage the soil conditions as close to 'natural' as possible and keep people from abusing the above ground portion, I think the other stresses are quite managable in many circumstances and trees will have the opportunity to thrive...that that is asking for a lot!


----------



## Corymbia (May 17, 2010)

*Soil is critical*



ATH said:


> In crappy soil
> 
> Soil restoration is a LONG process - probably at least a full generation of trees (not people), maybe 2 tree generations.
> 
> If we can manage the soil conditions as close to 'natural' as possible and keep people from abusing the above ground portion, I think the other stresses are quite manageable in many circumstances and trees will have the opportunity to thrive...that that is asking for a lot!



I am not so sure that soil restoration has to be a long process. 

I remember attending a lecture in Hawaii that showed a great tropical resort built on what had been lava flow less than 20 years before. Also had the chance to work in a number of arid regions and man made islands that are turned into tropical delights just by adding organic matter and water and the transformation is rapid. 

Cold dry regions now that is another deal but I guess that goes back to plant selection.

I do agree that if we can look after the roots the rest is comparatively easy.


----------



## Corymbia (May 19, 2010)

RyanMoster said:


> There is huge difference between urban and rural trees because in rural there is an open air atmosphere where as in urban there is a congested environment.



I'm not sure what "open air" and "congested" mean. 

Forrest trees have greater competition and CO2 helps increase growth. We have generally reduced sulfur and lead in our atmospheric pollution and we often have these underground irrigation system called leaking pipes.


----------



## Boa07 (Jun 5, 2010)

I am not certain what Ryanmonster was referring to but I suspect he might have been alluding to the very altered conditions that most (almost all) urban trees find with respects to the heat stress they experience.

The characteristics of the 'enclosed' urban tree are very hard to find mimicked in nature...high albedo pavements, convected heat flows from adjacent built infrastructure, irradiated heat from those same structures, and in many cities dramatically reduced solar access and natural air flows.

All these elements and we have not even started to consider the landscape below ground!



> Forrest trees have greater competition



Trees have evolved to grow in communities (inclusive of other tree species as well as shrubs, forbs and grasses) within an evolving ecosystem the relationships are just as often mutually beneficial and symbiotic as that community moves towards climax.

Very frustratingly the species palette I often see installed in our cities is something that will never escape from astronomical demands for resource inputs to prevent decline and entropy never attaining sustainable growth and stability.

As for finding professionals who understands what constitutes viable growing media for trees when and what soil amendments are appropriate..and just how much volume of suitable soil a mature tree requires.....well it seems the work of James Urban and Phillip Craul remain largely undiscovered despite having been forged back in the 1990's.


----------



## Urban Forester (Jun 5, 2010)

"Ryanmoster" is a spammer. They ACT like they are involved in the conversation, but each post contains links they hope your stupid enough to click on. Those links could have malware, spyware or ad tracking cookies or worse a virus. There are 2 or 3 of them working this site. If he's from Austria, I'm the Pope, most likely he's based in Nigeria. Note the syntax of the post, its bogus...


----------



## jefflovstrom (Jun 5, 2010)

Urban Forester said:


> "Ryanmoster" is a spammer. They ACT like they are involved in the conversation, but each post contains links they hope your stupid enough to click on. Those links could have malware, spyware or ad tracking cookies or worse a virus. There are 2 or 3 of them working this site. If he's from Austria, I'm the Pope, most likely he's based in Nigeria. Note the syntax of the post, its bogus...



I was told to ignore them or report them. This site is getting hit alot by them spammers. 
Jeff


----------



## Urban Forester (Jun 5, 2010)

I did report it. I'm sure most boards are dealing with this, a shame. Those clowns are always looking for ways to reach more people.


----------



## Corymbia (Jun 5, 2010)

*Persuasive but not convincing.*



Boa07 said:


> I am not certain what Ryanmonster was referring to but I suspect he might have been alluding to the very altered conditions that most (almost all) urban trees find with respects to the heat stress they experience.
> 
> The characteristics of the 'enclosed' urban tree are very hard to find mimicked in nature...high albedo pavements, convected heat flows from adjacent built infrastructure, irradiated heat from those same structures, and in many cities dramatically reduced solar access and natural air flows.
> 
> ...



That is like saying that a creature, confined in small spaces, regularly exposed to stress, constantly exposed to artificial lighting, fed on highly processed rather than natural foods and stuffed full of chemicals is life shortening. Of course we know that the human race is actually living longer as a result ...!?

Likewise many urban trees (as opposed to city trees) grow faster simply because they have exposure to more sunlight.

As for Urban and Craul's work ... I am not convinced that it is all new or necessarily critical. I agree that reducing the available soil volume reduces growth rates but then so do rocky crags and they are the source of the worlds oldest bonsai.

Of course it is not uncommon for scientific work to go largely ignored particularly in an industry where the majority of practitioners are not scientists. I am sure that I have a number of texts that are more than a hundred years old that have great stuff that is ignored ... try A British Winter Garden by William Barron for a starter ... Unfortunately the bulk of science goes unnoticed by most 

I really think the answer to the thread question is "yes and no"  Wish it was more black and white but I suspect that it isn't.


----------



## Boa07 (Jun 5, 2010)

Mark, your analogy of humans life span and tree life span is (as I suspect you know) weak at best, longevity in humans has a great deal more to do with improvements in sanitation than anything else.

Urban's and Craul's work is NOT all new and that is sort of my my point....much has been improved since they published their repsective texts, all to no avail when I view the ridiculous landscapes installed in our urban centres.



> Likewise many urban trees (as opposed to city trees) grow faster simply because they have exposure to more sunlight.



Hmmm something of a gross simplification that is I know intended to make a point but simply undermines your arguement for me, sorry. 

All plants (trees included) require a great deal more than just increased sunlight, you know that Mark. The urban environment consistently provides evidence of planners and architects failure to either understand or take into consideration the requirements that trees have for long term sustainable growth.....huge pot plants with the huge resources they demand is not what I consider to be sustainable nor desirable.

I would whole heartedly agree it is shades of grey everything is. 

Bad news for the professionals I have met in vegetation management who are selling an image that is only black and white without those shades...and consequently a reality they ignore and deny.


----------



## Corymbia (Jun 6, 2010)

Boa07 said:


> I would whole heartedly agree it is shades of grey everything is.
> 
> Bad news for the professionals I have met in vegetation management who are selling an image that is only black and white without those shades...and consequently a reality they ignore and deny.



Sean we agree completely 

Again I accept that using people is not a perfect example but it is interesting to note that exactly the same argument is used by animal liberationists against caged hens. The truth is we really don't know much.

I am sometimes concerned that we oversimplify things. Containers have solid sides and a bottom. I agree they are not always physical but I do constantly see nature breaking the rules and escaping the container even the physical ones. I also see nature adapting itself to the container and trees are a perfect example. Growth limited by container size is not necessarily unhealthy growth .. in fact with an appropriate species it is often healthy growth.

If a nursery full of pot bound pots is any indicator the greatest limit may in fact be water ... the stuff we catch of hard surfaces and in sub surface drains and divert into our rivers less the soil be replenished of its water.
I do see a time when that does not happen.


----------

