
Urban trees 'live fast, die young' compared to those in rural forests - dnetesn
https://phys.org/news/2019-05-urban-trees-fast-die-young.html
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atulatul
I highly recommend reading the book "The Hidden Life Of Trees" by Peter
Wohlleben

There is an informative chapter/section called Street Kids about trees planted
along the streets primarily in urban areas. How their health is impacted by
having no network of close cousins nearby to communicate/ suppy nutrients via
root/fungi, etc.

[https://www.amazon.com/Hidden-Life-Trees-
Illustrated/dp/1771...](https://www.amazon.com/Hidden-Life-Trees-
Illustrated/dp/177164348X)

~~~
sandworm101
There are also some advantages. Urban trees, being more spread out, sometimes
have greater sunlight and therefore grow faster. For some trees age isn't the
limiting factor but height. They grow until they risk toppling over.

So the urban tree does die "young", but is the goal to keep trees alive as
long as possible? If it is, then there are lots of things that can be done to
slow their growth and prolong their lives. Deprive them of nutrients. Shorten
their growing season. Keep them cold. Some of the oldest trees live in the
most extreme environments. Bonzi trees age very slowly too. Perhaps we should
trim our urban trees more aggressively.

[https://en.wikipedia.org/wiki/Methuselah_(tree)](https://en.wikipedia.org/wiki/Methuselah_\(tree\))
(5000+ years old, 10,000 feet above sea level)

~~~
atulatul
>but is the goal to keep trees alive as long as possible?

For some trees, being 100year old means that the trees are in their late
teens/twenties/thirties (source above book). With that in mind, the answer to
above question becomes somewhat difficult.

~~~
sandworm101
You are also applying mammalian standards to a plant. Trees may indeed be
capable of living a very long while, but that does not mean that such lives
are normal. A tree can live a full and productive life, reproducing and
spreading many times, centuries before its total lifespan. There is also some
speculation that trees may be immortal, that if their growth is artificially
managed that they may just never have to die. Plants are different than
mammals. They don't all have the same definitive life cycles.

------
nanomonkey
An article posted here recently ([https://blogs.scientificamerican.com/guest-
blog/botanical-se...](https://blogs.scientificamerican.com/guest-
blog/botanical-sexism-cultivates-home-grown-allergies/)) stating that urban
trees are also predominantly male (fruitless), which is causing a rise in air
pollen levels.

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guilhas
I think a bigger issue is healthy trees being cut in a lot of urban areas.

[https://www.dailymail.co.uk/news/article-5801627/Great-
tree-...](https://www.dailymail.co.uk/news/article-5801627/Great-tree-
massacre-Councils-cut-110-000-trees-desperate-bid-save-money.html)

Reference to UK, but I can see the same happening in Ireland and Portugal.

~~~
bryan11
Frequently, the first step when building in the US is to rip down any existing
trees and completely clear the property

~~~
Raphmedia
They recently did that in my area (rural/suburbs in Canada).

They cleared a huge section of old-growth forest to make a big community area
covered with grass.

Instead of keeping some trees aside or not clearing the whole thing, they
planted new young sapling all around the pedestrian paths and bicycle lanes.

Everyone is complaining about the lack of shade in that area (so big it feels
like you are standing in the middle of a plain) and the city's answer is:
"Sorry, we planted trees but they won't be big enough to cast shade for years.
Just be patient."

It feels ridiculous because the whole area is surrounded by forest.

~~~
holy_city
And then the trees will grow with the branches overhanging streets,
powerlines, and homes - prompting the city/power utility to trim them. But
naturally they won't hire arborists to do it.

The city of LA did that in my neighborhood last year. My street might as well
have no trees at all.

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neuronic
I wonder if urban trees will adapt to city life - but I guess it depends on
where the cities get their new trees. If it's not from the city's tree gene
pool we will put forest trees into cities and they won't far any better 200
years from now.

~~~
fathead_glacier
I think it will also involve selecting seeds only from "better" performing
trees from the city tree gene pool. This will then ensure that beneficial
mutations / changes survive. An unfortunate requirement of evolution to force
progress.

In a way it will be survival of the fittest for trees. Unfortunately it might
take considerable work from urban planners which I cannot see happening on a
large scale any time soon.

Maybe a better idea will be to selectively breed species in hard environments
and then distribute the seeds to cities that need them. With genetic
modifications becoming prevalent in the food industry this might be not far
away from happening.

~~~
ambicapter
> In a way it will be survival of the fittest for trees.

What if the "fittest" trees end up being the ugliest or most allergy-
triggering?

My point is if its run by humans, it probably won't really be survival of the
"fittest".

~~~
icebraining
If it's run by humans, then human decision becomes part of the selection,
shaping what "fit" means.

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oftenwrong
If you want to read the full study:
[https://journals.plos.org/plosone/article?id=10.1371/journal...](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0215846)

~~~
jcwayne
> _The role of street trees in the urban carbon cycle is complex as the
> environmental costs and benefits of street trees evolve over the course of a
> tree’s life, with emissions associated with establishment often precluding
> net greenhouse gas benefits in the early stages of a street tree’s life
> cycle. The carbon costs associated with nursery production, planting,
> irrigation, pruning, removal, and disposal are high. Street trees must
> survive for several decades (26–33 years) to attain carbon neutrality._

That's much longer than I would have expected.

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cicero
That's the urban lifestyle in general, isn't it?

~~~
ekianjo
Is this a joke? Life expectancy has been increasing as people left the
countryside for the cities. It's not even a matter of debate.

~~~
Symmetry
These days it is but back before the revolutions in public health at the turn
of the 20th century cities were very unhealthy, so much so that they tended to
be net consumers of population from the countryside even when they weren't
growing.

~~~
hinkley
Don't forget unions. We like to bag on them but factories with locked doors
burning down with the people still inside gave the unions the teeth they
needed to get things like that made illegal.

------
gdubs
Haven’t read the full study but I’m curious to see how much diversity is
factored in. In a lot of cities you see monocultures of the same “signature”
tree — which often leads to disease.

My instinct would be to focus on mixing things up, and making sure there’s a
wide diversity of trees; not just overall, but co-planting so there’s trees
mixed with shrubs, grasses, wildflowers, etc. Mimicking the multiple vertical
layers of a forest also maximizes photosynthesis so you get more carbon
storage per meter.

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cafard
Some do remarkably well in Washington, DC, given that they are planted between
sidewalk and curb. They don't get much salt, compared to what they would in
some northern states, there is that.

~~~
dsfyu404ed
DC (the cities and suburbs around it even more so) has a massive amount of
space between sidewalk and curb compared to older east coast cities that
weren't planned.

~~~
cafard
Really? I'd guess that in my neighborhood it's around three feet, certainly
not four.

------
debacle
I'll repost a comment I made a few years ago:

[https://news.ycombinator.com/item?id=14156934](https://news.ycombinator.com/item?id=14156934)

> I know a few arborists. This is generally the cycle:

> 1\. There is a tree problem.

> 2\. Muni orders some sort of study after the problem has become
> unassailable.

> 3\. Arborist performs a study, finds lack of naturalized species, lack of
> diversity, lack of appropriately spaced trees.

> 4\. Muni throws their hands up in the air because money and keeps doing the
> wrong things.

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tosser0001
In my city the DPW constantly drops a sapling in a sidewalk cut out with no
after care or follow up so they just die within a year or two. It seems like a
real waste.

I’ve always wondered what would happen if instead they really prepared the
soil and waited to see what trees naturally sprouted, then removed all but the
healthiest looking one.

------
kingkawn
I wonder if my house plants are suffering socio-chemical isolation by being
potted solo...

------
pvaldes
Probably as consequence of a mix among election of small species for small
spaces,

contamination,

jailed roots

and the social pressure to constant prune and mow until killing the tree.

Good luck trying to find a sanctuary protected in the next 400 years for a
fully fledged oak in the middle of a city.

------
thrower123
Hard to expect anything different. The amount of salt that they get exposed to
is horrifying, at least in places that experience cold temperatures and go
nuts with the calcium chloride to melt off every speck of snow and ice.

~~~
oftenwrong
There are some benefits for street trees that the article points out,
including less competition for light, more CO2, more nitrogen deposition, a
longer growing season, and the opportunity to tap water/sewer lines.

~~~
saltminer
> the opportunity to tap water/sewer lines

Does this involve breaking pipes? How exactly is it beneficial?

~~~
fredley
It's beneficial to the tree.

~~~
mikeash
Until they do it too much and get cut down for it, anyway.

------
ginko
But wouldn't that be good for carbon capture? Let the tree grow quickly, then
when it dies store the wood somewhere and plant a new one.

~~~
therein
Store the wood somewhere? Am I naive to think that it will be burned?

~~~
bluGill
Even burning isn't necessarily bad. Wood burned in nature (which we can
simulate easily) will leave a lot of unburned carbon behind in the form of
charcoal.

You have to deal with the air pollution though (which is a real problem, but
been going on for longer than humans).

------
cwkoss
More light, more CO2, more pollution. Makes sense that cities could encourage
faster growth and death.

------
papito
So do the people. It's the only way to be.

------
arjunbanker
are there any dense urban areas designed to coexist with healthy forests?

~~~
framebit
Arguably Atlanta, GA:
[https://en.wikipedia.org/wiki/Atlanta_tree_canopy](https://en.wikipedia.org/wiki/Atlanta_tree_canopy)

------
Joeboy
Live fast, die young, and leave a good looking copse.

~~~
cevn
Wow. Best joke I've seen this week at least

~~~
lostmsu
It is also a very old one.

~~~
IvyMike
Did you read 'copse' as 'corpse', or is this really a common joke?

~~~
lostmsu
I did. I am not a native language speaker, so I did not notice the difference.

------
buckthundaz
Civilization is an affront to nature -- it's amazing how few of us understand
this.

~~~
newswriter99
I love the debate about what is or is not "nature" these days.

We try to separate humans from other organisms because our use of
tools/building nests is so far advanced from say, what an ant produces, or a
bird making a nest, or a monkey with a stick.

But we're no different from those organisms in terms of tools and nesting,
we're just really good at what we do. You could argue humans are different in
that we possess self-awareness but that's an entirely different debate.

And then there's the "but what about our effect on the planet?" debate. What
about it? Some say the effect we have isn't natural. But even that only has
weight depending on what you mean by "natural". It's natural for humans to
terraform and move earth the way we see fit. At the moment we're at risk of
going extinct because of it, but the jury isn't out that we won't use
technology to once again survive.

~~~
buckthundaz
Look at the structural difference between systems of Nature and systems of
Civilization.

