
American Trees Are Moving West - bushido
https://www.theatlantic.com/science/archive/2017/05/go-west-my-sap/526899/?single_page=true
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fotbr
I wonder what affect 30+ years of "free tree" programs that various states and
environmental clubs run for arbor day and such has had. Growing up in the
midwest/great plains, ever year in elementary school we were given trees to
take home and plant for arbor day. Little sticks, maybe a foot long with a
small handful of roots, wrapped in damp paper towels to survive the trip home.

Someone says "oh, white oaks grow alright across the entire state, and their
acorns are a good food source for the local wildlife" and they send out a few
thousand of them for arbor day via elementary schools.

Some of them even survive. 30+ years later, those trees have dropped millions
of acorns, most of which feed squirrels and deer or rot away, but some turn
into trees.

Rinse and repeat every year. Seems like you could, over the course of nearly
40 years, unintentionally shift the population of a tree species.

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manarth
The interesting question for me is this: is there a reason to believe human
seed distribution is biased towards the west?

If it is human-influenced, what are the determinative factors? Do humans
favour certain seeds/trees in this selection? Are the seeds geographically
distributed evenly, or is distribution biased towards the west? Is the
westward growth bias caused by seed distribution, or locale viability? If
humans weren't distributing the seed, are there other vectors that would
provide an equivalent function?

~~~
Someone
I'm not saying it explains everthing they found (they may even have corrected
their stats for it), but the area they studied seems closer to the east coast
then to the west coast. Moving long distances east is hard there for trees.
First, they would hit larger populations centers; then, the ocean.

~~~
piotrkaminski
So basically they're moving west because there's more space there? ;)

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d4l3k
The "no one knows why" seems to be a stretch. It mentions in the article that
western areas are less moist and moisture levels have been increasing. Seems
like they're pretty confident that's the reason.

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firethief
Yeah, the <title> of the page is the non clickbait version: "Climate Change Is
Forcing Trees to Move Northwest". Completely at odds with the headerline...

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mabbo
What really should interest/worry you about this is the ecological changes
that will follow.

Different animals and birds have special relationships with certain types of
trees. When forests change, animals change. This can have a compounding
effect, as animal changes can change forests in turn. A few small changes here
and there can be the catalyst for much larger changes over time.

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yellow103
Doesn't say how much of this is due to new trees on the leading edge compared
to less trees on the other end. In the analogy of a line of people, adding
people to one end will move center that way as long as you don't add more to
the other. The trees could grow each way or shrink each way and still show a
movement, as long as one side is doing so at a different rate.

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Jabanga
Higher atmospheric CO2 levels allow plants to survive in lower precipitation
environments.

[https://www.sciencedaily.com/releases/2013/07/130708103521.h...](https://www.sciencedaily.com/releases/2013/07/130708103521.htm)

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sanatgersappa
Why not?
[https://www.youtube.com/watch?v=7NZ04BG7TfA](https://www.youtube.com/watch?v=7NZ04BG7TfA)

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justforFranz
Can you blame them? Look at how people vote East of the Pacific coast states.
It's disgusting. If I were a tree, I'd move immediately.

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cmurf
Trees have been around for a very long time, hundreds of millions of years.
Much longer than we have been. Possibly something they "know" at a genetic
level is a sort of risk assessment where species are calculating better long
term odds for the species based on local trend. They could be migrating toward
areas where less adaptation is needed to survive; or maybe even a substantial
but available path to adaptation via recessive genes.

This migration isn't the first. They've been doing this all along.

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all_usernames
My first thought upon looking at the map: they're moving away from the
coastline.

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ouid
what the hell does "only explains at least 20%" mean?

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nonbel
Its just another one of those fallacies about statistics people came up with.
[https://en.wikipedia.org/wiki/Explained_variation#Criticism](https://en.wikipedia.org/wiki/Explained_variation#Criticism)

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wmeredith
We know why. It's climate change. It says so in the freakin' article!

r/savedyouaclick

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piotrkaminski
Actually, no, it doesn't. The subtitle (!) is:

> Climate change only explains at least 20 percent of the movement.

So what explains the other 80%?

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djtriptych
"at least 20%"... so at most 100%?

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_delirium
Pretty much, yeah. "Fei and his colleagues argue that at least 20 percent of
the change in population area is driven by changes in precipitation, which are
heavily influenced by human-caused climate change". Could be more than 20%,
but that's what they have solid evidence for so far.

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fgrimes
Harumph.

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dang
Would you please not post unsubstantive comments to HN?

~~~
fgrimes
"It kills him when people say mean, stupid things in comment threads."

