Transcript

2.12.26 · Science Show KY

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Speaker 1: Welcome to radiois a diary of science and nature. My
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name's Kelly Taylor, and I'll be reading articles on the
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topics of science and nature. But first a reminder. RADIOI
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is a reading service intended for people who are blind
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or have other disabilities that make it difficult to read
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printed material. Starting off, we have an article from the
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Washington Post. Why do dead leaves stay on trees during winter?
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This is dated February two. Not all trees drop their
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leaves in the fall. Even in the height of winter,
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a curious number of oak and beech trees refuse to
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let go of their brown, brittle foliage. The delicate corpses
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rattle on the living branches until the warm season returns.
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This is not a new phenomenon. For at least two
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thousand years, people have documented the unusual sightings where certain
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decision u a species hold onto their dead leaves. It's
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called leaf marcessens, derived from withered in Latin. But the
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zombiesque scene contradicts our usual understanding of plants. Why would
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a tree cling to leaves that no longer feed it
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or help it grow? Is it an oversight? Maybe scientists
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are investigating why some plants still wear last season's tattered clothes.
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They found a surprising number of species hold onto their
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papery remains, but the explanations are anything but cut and dry.
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Marsessan trees have a certain beauty to them. Your eye
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is really drawn to these leaves that remain and rustle
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in the wind in the winter, said Mason Heberling, Associate
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Curator of Botany at the Carnegie Museum of Natural History. Quote,
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we have this relatively simple trait, but there's a lot
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of different explanations of how that trait exists. In Haberling
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didn't set out to investigate dead leaves on a tree.
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As a plant phenology researcher, he tracks the emergence of flowers, leaves, fruit,
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and also leaf drop, But he noticed a lot of
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trees around him held on to their rust brown appendages
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after autumn. How was he supposed to account for that
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in his leaf drop data set. Typically, deciduous trees pull
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back their resources from their leaves in autumn to make
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it through the cold season. They break down chlorophyll and
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send nutrients back to the trunk and roots. Then they
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physically seal themselves off by creating a layer of tissue
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called an abscission layer at the base of their leaves,
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eventually causing the leaves to die and fall, but marcessan
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plants don't form a complete layer and retain the withered
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leftovers for a little while longer. Haberling studied the winter
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behavior of ten medium sized beech saplings around his area,
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and his colleagues found younger trees tended to hold on
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to the relics and usually on their bottom branches. Naturalists
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from the eighteenth to nineteenth century found similar patterns in
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oaks and beaches in North America, but marsessence occurs in
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hundreds more species than previously thought. New investigations show across
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eighteen botanical gardens in North America, Europe, and Asia, a
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research project counted more than one thousand, sixty one different
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plant species in January twenty twenty four and twenty twenty five.
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They found that four hundred and one species across sixty
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families exhibited at least one percent of intact dead leaves.
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One hundred and fifty two species had at least twenty
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five percent. Some newly documented marsessan trees included some species
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of blueberries, azaleas, and honeysuckles. Again, they found that most trees,
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notably the Portuguese oak, American beech, and sycamore men retained
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more dead foliage on their lower branches. Plants of oh
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of colder climes also hold on to their paper remains more. Quote.
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What a really surprising result of this study is just
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how much more widespread leaf marcessens was than we had
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initially imagined, says Richard Primack, researcher in Boston University in
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part of the Botanical Garden Project. Quote. It was far
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more widespread than just oaks and beaches. It really occurred
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in a lot of genera or families that people hadn't
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imagined in quote. Even non woody plants like grasses, ferns, sedges, rushes,
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and some flowering plants retained leaf skeletons in some capacity.
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Another study for researchers in the Czech Republic analyzed one
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hundred and twenty seven herbaceous temperate species and found that
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almost all ninety seven percent, to be exact, exhibited some
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level of marcessens. Like a family habit that no one remembers. Starting,
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marcessence is more likely to show up in some plant
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species than others. Suggesting an evolutionary signal, said Matt Austen,
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leader of the Botanical Garden Research Project and Assistant curator
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of Biodiversity Data or Barium at Missouri Botanical Garden. For example,
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many oak tree species show high levels of marcessens, while
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ash trees hardly show inning. But it's more complicated than
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concluding that oak trees like to keep dead leaves. Austin
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said there's a lot of variation within a species where
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some red or white oaks show a lot of marcessens,
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but cousins may show none. It's clearly a heritable trait
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in red oaks, said mid Meg Stayton, research at the
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University of Tennessee Knoxville. She said the trait is either
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fully or partially controlled by genetics and passed down from
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parents to offspring, but she hasn't pinned on the specific
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genes involved. She and her colleagues found the region of
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the red oak genome that was linked to marciessence, but
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it had a whopping eighty genes that they have yet
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to analyze. But why would a plant decide to carry
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on or pass on such a tree. It turns out
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that lifeless leaves have quite a few advantages. A popular
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idea is that the unappetizing desicated leaves protect buds from
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the hungry mouths of deer, moose, and other large mammals.
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Tannins in the leaves create a bitter taste in large quantities.
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For example, an experiment in nineteen ninety two show that
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deer avoided branches of dead leaves on beech and hornbeam trees. Quote.
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Those dead leaves that are retained on there aren't very nutritional,
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said Heberley. Yuck, there's like a dead leaf in my mouth,
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and I wanted to get a nice living bud. Similarly,
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the remnants could provide physical protection for the buds against frost.
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More complicated theory is that the plants could keep their
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dead leaves to retrieve the nutrients for a later time.
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Marsessant leaves, although not as nutritionent rich as living leaves,
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decompose faster in the soil than leaves that fall in
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the autumn. Scientists have found that's because sunlight helps break
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down the hanging leaves, making them thinner and drier, sometimes
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pocked with holes. When those leaves finally hit the ground,
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they're already partially degraded and can return nutrients quicker to
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the soil than a fallen autumn leaf. Quote. The nutrients
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could be faster going into soil, and then they are
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again available for plants, said Sarka Angst, a soil scientist
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at check Academy of Sciences who led the study on
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decomposition in Marsessan leaves. Fast decomposition towards spring could help
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as a tree begins to grow again. Quote. There's also
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the possibility that the trade has no real value. While
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most assume a trade has passed on because it's advantageous,
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Habling said it could be passed down as a neutral trade.
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Whether a tree is Marsessan may not affect its ability
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to produce offspring, grow or survive. Habling surmised that the
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reason for these frail leaves is probably a combination of
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all those hypotheses and more that others haven't thought of. Quote.
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It just always reminds me that there's a lot about
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nature in our forests that we don't fully understand, but
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is really quite inspiring, he said. Our next article is
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going to come from Scientific American dated February third. The
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headline is spiders taught scientists how to make unsinkable metal.
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Toss a coin into a fountain, and you know what
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will happen. Being denser than water, the metal sinks, ask
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getting child. But new research has challenged centuries of certainty.
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A team at the Universe n of Rochester has etched
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aluminum tubes so that they won't sink even when damaged.
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A trick the scientists borrowed from spiders. Quote you can
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poke big holes in them, said Chun lay Go that
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spelled Guo, a professor of optics and physics at the
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University of Rochester and senior author of the research. Quote.
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We showed that even if you severely damage the tubes
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with as many holes as you can punch, they still float.
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In quote. Many things in our lives repel water. Examples
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include cooking oil, a rain jacket, or a rubber glove.
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Scientists call this property hydrophobe hydrophobicity hydrophobicity from the Greek
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for water fear, but the secret to the metal tubes
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buoyancy lies in super hydrophobicity. Woe's team uses lasers to
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our microscopic valleys into the aluminum that capture air. Picture
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corduroy fabric shrump down until it requires an electron microscope
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to see the ridges. According to the press release, the
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mechanism is similar to how diving bell spiders trap an
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air bubble to stay buoyant underwater. The spiders live almost
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entirely underwater, but still need to breathe. Their solution is
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to carry their own oxygen supply. Fine hairs covering their
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bodies trap air bubbles against their skin. The metal tubes
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mimic those fine hairs trapping their own air bubbles. Normally,
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water would spread along the inside walls and push the
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air out, but when it hits the superhydrophobic texture, it
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bounces away. Surface tension, the same property that causes water
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to beat on a waxed carhood, prevents the water from
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entering the tube. As a result, the air stays inside
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and the tubes remain buoyant. The study, published on January
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twenty seventh, twenty twenty six, in Advanced Funmational Materials, builds
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on woes earlier work designing unsinkable metals. In twenty nineteen,
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his lab demonstrated the concept using laser etched discs, but
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in turbulent water, the discs tipped and the air escaped.
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The new tubes solve that problem with an internal divider
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at the middle of the tube that helps trap the
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air in a confined chamber. Quote. Even if you push
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it vertically into the water, the bubble of air remains
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trapped inside and the tube retains its floating ability. Woe
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said in the same statement. The team tested the tubes
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in rough conditions for weeks and quote found no degradation
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to their buoyancy. He reported in Nature, superhydrophobicity is in
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a new trick. The eyes of mosquitoes have water repellent
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nanostructures that keep them clear, for example, and fire ants
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use their waxy water repellent coating and textured exoskeletons to
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trap air during floods. Thousands cling together to make buoyant
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living rafts that can survive twelve days and possibly longer
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as for humans. This is in our first attempt at
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floating metal, and twenty fifteen, researchers at New York University
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embedded hollow silicon carbon spheres in a magnesium alloy to
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create a metal matrix composite lighter than water. But the
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implications of woes work go beyond the laboratory. Linked tubes
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could create weight bearing rafts or ships. Engineers might be
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closing in on the dream of ships that stay afloat
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even as water pours into their hulls. One surprising application
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involves energy. Woes team demonstrated that rafts made of the
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tubes could harvest waves to generate electricity. The tubes are
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currently nearly half a meter long, but Gwoe sees no
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barrier to increasing their size. The lasers are now seven
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times more powerful than they were in twenty nineteen when
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Wove attempted laser etched metal discs. The technology, he said
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in the same statement could be easily scaled two larger
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sizes now will turn to Smithsonian. They have an article
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that's headlined Snow drought hits the Western United States, worrying
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experts about the region's water supply. Is from February tewod.
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While winter weather blanketed much of the United States in
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snow last week, mountains in the western part of the
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country are sparser than usual. The amount of compressed snow
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or snow pack in some spots has hit historical lows,
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culminating in a snow drought. Colorado's snowpack is quote the
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lowest on record for this point in the season. Says
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Peter Goebel, Assistant State climatologist of Colorado. Utah is in
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a similar situation, as well as certain places in California,
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says Daniel Swain Climb, Scientists at the University of California
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Agriculture and Natural Resources. Quote. At least one ground based
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monitoring station in every major Western watershed recorded the lowest
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amount of water stored in the snowpack in at least
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twenty years on January twenty sixth. That's not just bad
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news for winter sports enthusiasts. Snowpack is a natural reservoir
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of fresh water which slowly melts and provides up to
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seventy five percent of the West's annual water supply. The
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diminished snow melt will likely add to the mega drought
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currently burdening the Colorado River, and it could exacerbate regional
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wildfires come summer. The snow drought seems to partially be
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a consequence of unusually toasty temperatures quote. Washington, Oregon, California,
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and many Western states had their warmest December ever on record,
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says Phillip Mote, a climate scientist at Oregon State, and
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so the torrential rains that we had with the atmospheric
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river and the flooding and damage from too much water.
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None of that stayed in the mountains. Instead, the Pacific
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Northwest's rainstorm that took place from December first to December
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fifteenth melted much of the snow and quote paradoxically left
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the region's water supplies worse off in its wake, writes
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Alejandro Flores, hydrologist at Boise State University. And more recently,
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much of the West has been experiencing an unusually long
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dry spell, meaning the snowpack isn't getting replenished. Scientists can't
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pinpoint the exact region reasons for the region's recent weather conditions,
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since it's difficult to attribute the snow drought to climate
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change alone, reports Jim Robbins at The New York Times. Still,
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computer simulations that forecast weather suggests that the events aren't
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merely a one off. Quote. The predictions are we will
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get less snow because the precipitation base will be rain
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rather than snow, and the line at which snow accumulates
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will keep creeping up, says Mackenzie Skiles, snow hydrologists at
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the US University of Utah. The snow drought comes at
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an already bleak time for the Colorado River basin, which
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supplies water to forty million people and has been experiencing
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a historic drought since two thousand. Western states have been
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negotiating management of the river's dwindling resources for years, and
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the snow drought makes the situation even more pressing. More
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than half of the West's runoff water that flows into
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bodies of water comes from snow melt. Policymakers from seven
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states met last Friday to reach a new water sharing agreement,
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but for now they remain at an impasse. In the
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short run, having a low snowpack year may raise the
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urgency of coming to some of those agreements. Gobal tills
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NBC News. The conditions have also affected the region's ski industry.
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For instance, the company Vale Resorts said that only eleven
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percent of its terrain in the Rocky Mountains was open
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in December, and snowfall then and during the previous month
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was sixty percent below average. February and March might bring
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more snow, although that may not make up for the
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current deficit. In places such as the Pacific Northwest and
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the Colorado River basin that are already dry snow drought
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may turn into or exacerbate traditional drought. Additionally, more arid
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conditions could exacerbate wildfire risk by creating an abundance of
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dried plant matter, which is the primary fuel for fires.
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Climate change enhanced a drying has roughly double the area
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of forest fires in the West from nineteen eighty four
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to twenty fifteen. Experts are now working on ways to
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better predict snow drought and its consequences, work that will
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become more important as the events become more common. Flores wrote,
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now we'll go to a BBC wildlife. This headline reads,
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humans descend into huge deep sea canyon for the first
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time ever. What they find is astounding. An underwater expedition
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into Argentina's Mar del Plata Canyon has uncovered a wealth
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of marine life, including glowing squid, pink lobsters, sprawling coral gardens,
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and rare invertebrates, along with forty species believed to be
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new to science. Led by Argentinian scientists aboard Schmidt Ocean
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Institute's research vessel Falcore, the mission offered the public a
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rare chance to witness deep sea exploration in real time.
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With nearly four million people tuning into their live stream
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over three weeks. The team used the institute's remotely operated
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vehicle or ROV, called the Subastian, to descend to depths
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of more than thirty five hundred meters, almost twice as
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deep as the Grand Canyon. This marked the first time
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scientists had directly observed the canyon floor, having previously relied
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on samples collected by nets and trolls. Quote. The deep
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sea and its awe inspiring life from bright corals to
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mesmerizing octopuses has captivated an entire nation thanks to a
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team of passionate scientists and the millions of people watching
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their work via live stream, says Wendy Schmidt, co founder
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and president of Schmidt Ocean Institute. Quote. Argentina is showing
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the world the power of deep sea exploration to not
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only spark wonder, but to remind us how much of
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our planet remains to be discovered and protected in quote.
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The mar del Plata Canyon, located three hundred kilometers offshore
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from the city of Mar del Plata, is one of
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Argentina's largest submarine canyons at one thousand, fourteen meters. The
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team found a reef of Bethelia candida, a stony coral
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that creates habitat for other marine life. At fifteen hundred metres,
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they documented an extensive bed of red Anthomastus, a mushroom
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shaped soft coral. Other species recorded included cnmones, sea cucumbers, urchins, snails, corals,
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and crinoids. While many are thought to be new to science,
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official confirmation will require detailed taxonomic work. The expedition reached
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unprecedented public engagement for the Schmidt Ocean Institute. While typical
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dives averaged four thousand online views, this mission drew an
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average of five hundred thousand per dive, amassing more than
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seventeen and a half million views in total. Roughly seventy
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five per cent of viewers were from Argentina, where the
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livestreams were watched everywhere from classrooms to gyms. It has
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been incredible to see how people of all ages have
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connected with the deep sea, says researcher Martin Broger. We
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received hundreds of messages from families, teachers and kids who
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felt inspired, surprised, and even emotional watching the live broadcasts.
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Some young students told us they now dream of becoming
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marine biologists. And an impact that goes beyond science by
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creating a shared sense of wonder and curiosity that can
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truly last a lifetime. Chief scientist Daniel Loretta says one
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of his favorite moments was seeing videos of children pretending
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to pilot their own rov quote. Those videos filled my
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heart with joy and hope for the future. He adds,
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not all discoveries were natural wonders. The team also found
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human debris, including shoes, plastic bags, and fishing gear, evidence
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that human impact reaches even the ocean. This cruise underscores
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the power of ocean exploration and science in igniting the imagination,
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says Schmidt Ocean Institute's executive director Joetika Vermani. It was
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inspiring for us to see Argentinians fall in love with
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their own deep sea and we are grateful to the
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science team who balanced the demands of seagoing science with
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their passion to share their research with millions. Now we'll
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go back to Scientific American and this article from February
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the fourth is headlined. NASA document reveals new Artemis two
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Moon mission target launch dates for March. NASA document showing
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the potential launch windows for Artemis two Moon mission appears
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to have been quietly updated on Wednesday, with the agency
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highlighting March sixth through the ninth and March eleventh as
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possible target dates. NASA said Artemis two would slip to
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a March launch date after a critical test of the
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mission's spacecraft, the so called Wet Dress rehearsal went awry
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on Monday. During the test, the SLS or space launch
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system sprang hydrogen fuel lea leaks, a problem that plagued
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the mission's predecessor, Artemis I, despite trying to stem the
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leaks using techniques learn from Arto's I. However, NASA engineers
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still have some work ahead to fix the SLS problem,
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and the spacecraft's capsule, designed to ferry a crew of
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four astronauts in a loop around the Moon and back,
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encountered problems with a valve. When exactly Artemis two will
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launch depends on a successful rehearsal. That date is to
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be determined, in which NASA will attempt to fuel the
23:53
rocket again and test its systems without the crew on board.
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NASA did not immediately respond to requests for comment. If
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that goes to plan, then we could see the agency's
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next mission to the Moon launch within a month. If not,
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NASA's documentation shows the agency could target early April instead.
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And now we've got an article from euro News why
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scientists want to build a wall along the Doomsday Glacier.
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This is from the second of February. A global group
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of scientists, engineers and policy experts has unveiled an ambitious
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plan to build a wall along the Doomsday Glacier as
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flooding fears continue to grow. Located on the West Antarctic
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ice sheet, Thwaite's Glacier earned its apocalyptical name due to
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its potential impact on sea levels. Covering a vast one
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hundred and ninety two thousand square kilometers, making it comparable
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in size to Great Britain, the glacier is melting at
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an unprecedented rate due to human fueled climate change. Already,
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four percent of the world's annual sea level rise is
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due to Thwaite's current ice loss, as heat trapping gases
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continue to bake the planet. If it were to collapse completely,
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sea levels could increase by a staggering sixty five centimeters.
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For every centimeter of sea level rise. Around six million
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people on the planet are exposed to coastal flooding, But
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can the consequences of climate change really just be barricaded
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off the seabed. Anchored Curtain project aims to limit sea
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level rise by creating physical barriers that would protect ice
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sheets from warm ocean waters that flow underneath the fringing
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ice shelves. It argues that a reduction in greenhouse gases
25:55
alone will not be enough to stabilize the ice sheet,
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and engineers from Cambridge University, the University of Chicago, Alfred
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Wegener Institute, New York University, Dartmouth College, NIVA, Acre Solutions,
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and the University of Lapland's Arctic Center are teaming up
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to design a curtain around one hundred and fifty two
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meters tall and eighty kilometers long. It's a bold plan,
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one that will take years to achieve if it ever
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comes to fruition. The team has established a roadmap that
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includes a three year research program to design curtains and moorings,
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decide on which materials could be used, and to construct
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and test the technology to make sure it can restrict
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warm currents. Already, mooring data is being retrieved from the
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Foyts Glacier, while a fundraising campaign aims to raise ten
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million dollars quote. Over the current three year program, we
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will target the technology development, engineering and scientific testing of
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prototypes deployed at a few yord site in Norway, the
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Seabed Curtain Project, says quote. In parallel, we will continue
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to develop our relations with indigenous peoples of the Arctic
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and representatives of the most affected countries in the Global South.
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Researchers from the UK and Korea recently reached the most
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inaccessible and least understood part of Thwaite's glacier, where they
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will drill one meter deep into the ice to directly
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observe how warm ocean water is melting it from below.
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Over the next couple of weeks, the team will use
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hot water drill to bore through the ice and deploy
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instruments will send back the first real time data from
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the location. It marks the first time that hot water
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drilling has taken place on the main trunk of the
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Thwaite sized shelf, an area notorious for its crevasses and
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quick movements. Quote. This is one of the most important
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and unstable glaciers on the planet, and we are finally
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able to see what has happened where it matters most,
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says doctor Peter Davis, physical oceanographer at the British Antarctic Survey.
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That's all for today's Diary of Science and Nature. Your
28:11
reader was Kelly Taylor. Now stay tuned for further programming
28:15
on RADIOI