Amazing nature

[samaritan]

I recently watched a show on the discovery channel, where a guy described how a tree absorbs sunlight thru it's leaves and bark, converts it into energy, and stores it in the wood, and how when we burn it we are releasing all of that energy it accumulated over its lifetime, a wonderful amazing process.

 

[buzz sawyer]

What amazes me is how the tall redwoods and sequoias overcome gravity and get water up to the leaves.

 

[Seachaser]

Amazing that a tree can be grafted and it will hardly be noticeable down the road.

 

[ericm979]

Redwood trees have two different types of needles. Most of the needles absorb sunlight and C02 and turn that into energy, like regular needles and leaves on trees. But there are some special needles whose primary function is to absorb water. When I was studying this stuff it was known that fog drip was a major source of water for redwoods. If you're in a redwood forest in the fog the amount of water coming off the trees can be substantial. The range of redwoods pretty closely follows the summer fog line. It was thought that the water dripped on the ground and was absorbed by the roots in the soil. But now they found out that some needles absorb water directly.

 

[Automender]

Redwood trees have two different types of needles. Most of the needles absorb sunlight and C02 and turn that into energy, like regular needles and leaves on trees. But there are some special needles whose primary function is to absorb water. When I was studying this stuff it was known that fog drip was a major source of water for redwoods. If you're in a redwood forest in the fog the amount of water coming off the trees can be substantial. The range of redwoods pretty closely follows the summer fog line. It was thought that the water dripped on the ground and was absorbed by the roots in the soil. But now they found out that some needles absorb water directly.

I believe those needles that absorb water directly are high in the tree where the wood cells can't overcome the pressure of the column of water at that height.

 

[ericm979]

I think redwoods are still limited to the height that they can draw water to due to water's surface tension. The theoretical height limit due to surface tension is about 420ft (there's some disagreement in the literature) but we don't see trees quite that tall. I think the tallest known redwoods are in the 380 ft range.

The placement of the water absorbing leaves in redwood trees seems to vary depending on local climate, at least according to this article: https://www.scientificamerican.com/article/redwoods-grow-weird-leaves-to-suck-water-from-air

I think this discovery is pretty recent and there may be more to find out about it.

Another related fun tree fact: the xylem is the part of the stem that conducts water upwards to the leaves. It's made of dead cells and is basically a set of microtubes that functions like a long straw. This is why surface tension is a limiter to tree height. The tree trunk should be under suction because of it. But the phloem (outer layer under the bark) can contain water under pressure. Anyone who has stuck an increment borer (or started a cut with a saw) in a white fir will know why it's called "piss fir" pretty quick. With the increment borer you learn to stand to the side.