Trees' Leaves Grow At a Cool 70° All Over the World 537
biogeochick writes "Ever turn on the air conditioner on a hot day? How about a heater when it gets cold? OK, so we all know that humans act to keep themselves cool, but what about trees? A recent article on tree core isotopic evidence has shown that trees from tropical to boreal forests all grow at 70 degrees. The study, published in Nature by some fantastic researchers (so one of them is my adviser, so sue me) and covered by NPR on All Things Considered, has shed some light on the convergent temperature at which trees perform photosynthesis." Update: 06/19 21:31 GMT by T : I give, I give -- that's 70 degrees Fahrenheit.
Why are plants green? (Score:2, Interesting)
pretty thin science... (Score:5, Interesting)
The second contains "warm" and fuzzy quotes like the following:
"Trees in chilly climates also have ways to make their leaves or needles retain more heat from the sun. Pine needles, for example, clump together. Think of gloves and mittens, Helliker says. If you're wearing gloves, wind can easily whip heat away from your individual fingers, leaving you cold. But if your fingers are all together in a mitten, they're going to be warmer.
Richter says the discovery isn't just fascinating science. It gives her a special kinship with trees.
On a recent day in Philadelphia when the mercury was near 100 degrees, she said, "I was staring at a hickory tree and its leaves were down â" they had wilted," she says. "And I was thinking, hey, it's hot, I'm hot. They enjoy 70 degrees, and I enjoy 70 degrees, too.""
A special kinship with trees?!? How did this make it to Nature?
Re:Or in Celsius (Score:3, Interesting)
'Round here 32F can be shorts, t-shirt and sandal weather. OC just sounds too cold for such a warm day.
Sure, eventually Celsius catches up but that point tends to fall outside of standard human operational temperature range.
Humans are 98Â but prefer 72Â (Score:5, Interesting)
I find it even more remarkable that trees prefer nearly the same temperature that humans do.
Jesus F Christ (Score:4, Interesting)
Having lots of thin needles near each other is actually a pretty good heatsink design. No, seriously. Not as good as some ducted designs, and not as cheap to make as shaved copper fins, but nevertheless, if you're going to blow air through it, it gets heat out rather impressively well. Per weight, it has a _lot_ of surface to exchange heat through.
Evergreens don't "stay warm like fingers in a mitten" in winter, but, among other things, have one or more of the following reasons for what they are:
1. The needles allow the snow to fall off the trees easier than a broad leaf. (But not all evergreens have needles, btw.)
2. Many contain chemicals that act, effectively, like anti-freeze. You can't stay warm like fingers in a mitten when you can't produce your own warmth. Your fingers stay warm in a mitten just because they produce their own heat, and the mitten keeps it in. If you were cold blooded, like a tree, even keeping them tight together and even a mitten wouldn't last you all winter. The best you can do is try not to freeze as early.
But even so, they're photosynthesizing a lot slower in winter, and when the temperature drops enough and that water freezes anyway, not at all.
3. They grow in areas with less sunlight, warmth and soil nutrients, so they can't afford to just lose the leaves and consume nutrients to make more in spring. So even if temperature drops enough that they do freeze, they keep their leaves because they can't afford to just drop them all and make a new batch later. They keep their needles for _years_.
4. The thick needles and waxy cover help conserve water. Basically they try to lose as little as possible, among other things, because #2 and because getting more from the ground is a pain in winter anyway.
So, seriously, this looks to me like the most retarded kind of pseudo-science. The kind that just imagines some fairy-tale explanation. Worse yet, one based on little more than anthropomorphizing the damn trees.
Re:Shameless karma whore (Score:5, Interesting)
That's nuts! An AVERAGE temperature to calibrate a thermometer? That's the same thing as calibrating my speedometer in my car to the average speed of a laden swallow.
Base-10 Sucks (Score:3, Interesting)
Base-10 sucks, too few prime divisors.
The Egyptians figured out children could learn to count in base 12 on their finger knuckles just fine. That way we won't have to start navigating in radians to get to your base-10 nirvana.
Re:Shameless karma whore (Score:2, Interesting)
Re:Or in Celsius (Score:5, Interesting)
Again, for those not paying attention: precision has not always equaled utility.
1) the Imperial measures are far more human-friendly than metric. Metric is WONDERFUL in a computer-driven world, but for everyday measures, a number of imperial systems are much more practical:
a) Temperature: Fahrenheit based his temperatures on a likely-to-be-experienced-by-people scale. Since he was in Copenhagen, this meant typically 0-100. Humans don't really care about precise temps, so the greater precision of Fahrenheit is meaningless, it just suits human penchant for round numbers. (FWIW, Celsius *did* originally arrange his system in reverse, with water freezing at 100 and boiling at 0...)
b) linear: again, for the bulk of human history, utility has NOT been measured by decimals, but by simple calculation. The foot, divided into 12 subunits (each, conveniently for a carpenter, about a male thumb-width), is (integer) divisible by 12, 6, 4, 3, 2, and 1. The larger unit of a yard (~1m) is integer divisible by 36, 18, 12, 9, 6, 4, 3, 2, and 1. Decimals, on the other hand, are divisible by 10, 5, 2, and 1. Certainly, large maths are much more easily worked in metric measures, but again, in typical parlance, humans don't use large maths when they don't have to - we don't measure soccer fields in mm, for example.
As far as American usage is concerned, it's already been stated: US citizens have routinely and widely switched to SI units for anything that matters. I work in logistics, and am routinely converting from cubic inches to cbm, from lbs to metric tons, etc. No big deal - but for some reason the REST of the world feels entitled to complain about what units WE use? I genuinely don't get that. Do Americans get to complain that Egyptians speak Egyptian, because it makes it harder for us to do business in Egypt? I don't think so.
And for the snide comments about the unit-conversion causing the loss of a Mars probe...well, at least we're a technologically-successful-enough state that we're tossing probes at Mars, despite our "imperial units handicap"....
According to http://en.wikipedia.org/wiki/Exploration_of_Mars#Mars_Curse [wikipedia.org], there have been 43 missions to Mars, 20 by the 'benighted' Americans, and 23 by other nations presumably not hobbled by their attachment to an archaic system of measures.
American success rate is running at 70%.
"Other" success rate is running at just over 30%, depending on how you count it.
Perhaps you guys should try Imperial measures? Maybe that might work better?