An Arbor Embolism? Why Trees Die In Drought
Excerpt:It has to do with the way trees drink. They don't do it the way we do — they suck water up from the ground all the way to their leaves, through a bundle of channels in a part of the trunk called the xylem. The bundles are like blood vessels. When drought dries out the soil, a tree has to suck harder. And that can actually be dangerous, because sucking harder increases the risk of drawing air bubbles into the tree's plumbing. Enlarge Herve Cochard/Nature An air embolism in a narrow water-transporting cell in a leaf of a walnut tree, captured using light microscopy. Drought stress increases the likelihood of embolism, reduces photosynthesis and may eventually lead to plant death. Herve Cochard/Nature An air embolism in a narrow water-transporting cell in a leaf of a walnut tree, captured using light microscopy.
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Brendan Choat
Overall Sentiment: -0.348228
Relevance: 0.788066
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| -0.382838 | Brendan Choat explains: "As drought stress increases, you have more and more gas accumulating in the plumbing system, until they can't get any water up into the leaves. This is really bad news for the plant because this is like having an embolism in a human blood vessel." |
| 0 | "So this is the key thing," Choat says, ... |
| 0 | "So this is the key thing," Choat says, "that it would only take a small shift in terms of the moisture environment, the temperature ... to push these plants across the threshold." |
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Bettina Engelbrecht
Overall Sentiment: -0.080662
Relevance: 0.445006
| Sentiment | Quote |
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| 0 | "Instead," she says ... |
| -0.382008 | "Instead," she says of Choat's research, "we find, well, it's all the same — everyone is right at the edge and has a very risky strategy." |
| -0.287024 | "Now, we have to worry about all of them," she says. ... |
| -0.0784442 | "Now, we have to worry about all of them," she says. "We have to really deal with the problem at the global scale." |
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Nathan McDowell
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Scientists who study forests say they've discovered something disturbing about the way prolonged drought affects trees. When drought dries out the soil, a tree has to suck harder to draw in water. But that increases the risk of drawing in dangerous and deadly air bubbles.
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An Arbor Embolism? Why Trees Die In Drought
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