Speaker 1: Welcome to Brainstuff, a production of iHeartRadio, Hey brain Stuff
Speaker 1: Lorn Vogel bomb here. Back in two thousand and eight,
Speaker 1: a study proposed that the maximum height for a Douglas Fir,
Speaker 1: one of the world's tallest types of trees, is right
Speaker 1: about at four hundred and fifty three feet. That's one
Speaker 1: hundred and thirty eight meters. But why is there a
Speaker 1: specific limit. Trees are nature's skyscrapers, but as it turns out,
Speaker 1: nature has hemmed them in. That's because trees can only
Speaker 1: physically pull water so far up their trunks. The transporters
Speaker 1: in question are a type of dead cells called tray kids,
Speaker 1: with deep pits that help move water from one long,
Speaker 1: skinny cell to the next. The diameter of these all
Speaker 1: important pits shrinks as you ascend into a tree's upper reaches,
Speaker 1: complicating water transport. Eventually, the flow of water reaching the
Speaker 1: leaves and branches near the top dwindles or stops entirely,
Speaker 1: and the struggling sections experience drought stress and they become
Speaker 1: dehydrated and die, establishing a de facto maximum height for
Speaker 1: that tree. Researchers think these progressively narrowing pits actually help
Speaker 1: trees survive. A height poses the problem of air bubbles.
Speaker 1: The taller the tree, the more likely it will develop
Speaker 1: a xylum embolism, which is when air bubbles get in
Speaker 1: and block the passage of water through the xylum, which
Speaker 1: is the tissue that makes up a tree's vascular system
Speaker 1: and allows it to transport water and minerals from the
Speaker 1: roots to the rest of the plant. A xylum embolism
Speaker 1: is similar to a human air embolism, in which air
Speaker 1: enters the bloodstream and causes potentially severe complications. The trachid's
Speaker 1: chain shape near the top of the tree to try
Speaker 1: to prevent such air bubbles and withstand the increased pressure
Speaker 1: of water being pulled three hundred feet up in the air,
Speaker 1: but that protection comes at a price less water and
Speaker 1: as the ree searchers suggest, a cap on how tall
Speaker 1: trees can grow. Another tree height study positive the maximum
Speaker 1: height of all trees at four hundred and twenty six
Speaker 1: and a half feet or one hundred and thirty meters.
Speaker 1: The study examined coast redwoods, currently the world's tallest trees,
Speaker 1: and based projection on factors like existing weather conditions, photosynthesis levels,
Speaker 1: water flow, and carbon dioxide levels. And not surprising. Health
Speaker 1: factors like water flow and photosynthesis decreased in the higher
Speaker 1: portions of the massive trees, while unhealthy factors like carbon
Speaker 1: dioxide increased, But ultimately, as with the furs, it all
Speaker 1: comes down to xylum. These redwoods pull water up through
Speaker 1: their trunks as other trees do, although they can absorb
Speaker 1: some water from the fog that often surrounds them in
Speaker 1: their native California and Oregon environments. Before attaining their maximum height,
Speaker 1: they shoot up about ten inches that's twenty five centimeters
Speaker 1: every year. But of course, tree size is more than
Speaker 1: just height. The world's heaviest and most voluminous tree is
Speaker 1: General Sherman, a giant sequoia, one of two types of
Speaker 1: redwood found in California, the other being the taller, skinnier
Speaker 1: Coast redwood that we just mentioned. General Sherman is estimated
Speaker 1: to weigh over six thousand tons and encompass fifty two
Speaker 1: thousand cubic feet that's about one thousand, five hundred cubic meters.
Speaker 1: Located in California's Sequoia National Park, General Sherman is two
Speaker 1: hundred and seventy five feet tall that's eighty four meters
Speaker 1: but it's not the world's tallest tree. That honor belongs
Speaker 1: to a coast redwood named Hyperion, which clocks in at
Speaker 1: three hundred and seventy nine feet tall that's one hundred
Speaker 1: and fifteen meters. A general Sherman also isn't the world's
Speaker 1: widest tree. It has a trunk circumference of one hundred
Speaker 1: and two feet or thirty one meters, but it's beat
Speaker 1: out by l Arbol de Tule in Wajaca, Mexico, which
Speaker 1: has a maximum circumference of one hundred and seventy eight
Speaker 1: feet or fifty four meters. So there are different ways
Speaker 1: of considering tree size, just as there are various ways
Speaker 1: of considering what might be the world's largest living organism.
Speaker 1: Some scientists consider massive reefs like Australia's Great Barrier reef,
Speaker 1: to be giant singular organisms. There are also huge fungi
Speaker 1: out there, such as a fungus discovered in Washington State
Speaker 1: that spans one five hundred acres that's six hundred hectares.
Speaker 1: But we are talking about trees here, and the world's
Speaker 1: most massive living organism may be one group of quaking
Speaker 1: aspen trees located in the mountains of Utah and nicknamed
Speaker 1: Pando Latin for I spread. A Pando is considered one
Speaker 1: organism because the trees in the group share an identical
Speaker 1: genetic code and a common interconnected root system. The Pando
Speaker 1: trees are basically clones of one another, and new trees
Speaker 1: are made as stems spread out as far as one
Speaker 1: hundred feet or thirty meters from the base of the
Speaker 1: original tree and then periodically take root, creating new genetically identical,
Speaker 1: interconnected trees. The process, known as vegetative reproduction, is also
Speaker 1: how strawberries and many other plants reproduce. Pando is made
Speaker 1: up of some forty seven thousand trees spread across one
Speaker 1: hundred acres or forty hectors, and maybe up to eighty
Speaker 1: thousand years old, but in testament to the massive size
Speaker 1: of California's redwoods, this batch of forty seven thousand trees
Speaker 1: weighs only about six thousand, six hundred tons, only a
Speaker 1: little bit more in total than General Sherman. Today's episode
Speaker 1: is based on the article how Tall can a Tree Grow?
Speaker 1: On HowStuffWorks dot com, written by Jacob Silverman. Brainstuff is
Speaker 1: production by Heart Radio in partnership with Hostiff Works dot
Speaker 1: com and is produced by Tyler Klang. Four more podcasts
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