News / Science & Technology

    Study: Plants Might Lack Traits Needed to Cope With Climate Change

    Plants have evolved defenses, like dropping their leaves, to adapt to cold, harsh climates. (Simon Uribe-Convers)
    Plants have evolved defenses, like dropping their leaves, to adapt to cold, harsh climates. (Simon Uribe-Convers)
    Rosanne Skirble
    A new study suggests that modern flowering plants, trees and agricultural crops may not have the characteristics, or the time, to respond to rapid human-induced climate change.
     
    The report in Nature looks at how plants evolved to cope with cold in the past, but finds these same mechanisms may not provide the same defense against human-induced climate change.

    Survival traits
     
    Flowering plants lived in warm tropical climates 243 million years ago. Since then, they have spread across the planet into much harsher places. George Washington University ecologist Amy Zanne and her colleagues wanted to understand how the plants survived in a colder environment. 

    • Sunrise through an oak-hickory forest canopy at Tyson Research Center, Washington University in St. Louis, Missouri. (Jonathan Myers)
    • The leaves of a sugar maple start to yellow as winter approaches, Tyson Research Center, Washington University in St. Louis, Missouri. (Jonathan Myers)
    • An ornamental cherry tree loses its leaves in the fall at the Tidal Basin, Washington, DC. (Amy Zanne)
    • A frost covered dandelion head spreads as winter arrives at the University of Idaho Arboretum, Moscow, Idaho. (Simon Uribe-Convers)
    • A birch leaf turns a bright yellow as winter approaches, Gateway Arch, St. Louis, Missouri. (Amy Zanne)
    • Maple leaves change colors before they fall in Rock Creek Park, Washington, DC. (Amy Zanne)
    • Early winter brings out the reds and oranges on sugar maple trees at the Gateway Arch, St. Louis, Missouri, USA. (Amy Zanne)
    • Buckeye leaves emerge in the spring after the winter frost at Forest Park, St. Louis, Missouri. (Amy Zanne)
    • Newly emerged tulip poplar leaves in spring after winter frost at Joyce Kilmer Memorial Forest, Robbinsville, North Carolina. (Amy Zanne)

    They identified three traits that help them do that: dropping their leaves before the winter chill, narrowing the cells that transport water from the roots to the leaves, and dying back to the ground and re-sprouting from their roots or seeds in the spring.     
     
    “The next bit was, we wanted to not just look at where species are today and whether they are seeing freezing or not, but to try to understand the evolution of these characteristics and the order of the evolution of those characteristics or those traits,” Zanne said.  

    Evolutionary tree

    To do that, the researchers constructed the largest-ever time-scaled evolutionary tree of 32,000 plant species. They then compared the emergence of those adaptive traits with big changes in the Earth's climate to reconstruct how plants evolved with the cold as they spread across the globe. 

    LISTEN: Plants Might Lack Traits Needed to Cope with Climate Change
    Study: Plants Might Lack Traits Needed to Cope with Climate Change i
    || 0:00:00
    ...    
     
    X

    “We saw for all three of the traits, there was a really strong support for finding a shift into freezing and also a shift in the trait. And so to tough it out and deal with the cold, what they did was they made these narrower pipes so that they wouldn’t get these air bubbles that blocked the water through the stems," Zanne said. "So they could maintain that stem by keeping those small pipes.  Or what they did was they dropped their leaves. So they didn’t have to keep their leaves from year to year. Or the third thing that they did was they avoided or hid from the cold altogether by becoming herbaceous.” 

    Herbaceous plants have leaves and stems that die back to the ground in winter. 
     
    Zanne says one of the most significant findings was that the changes occurred even before the plants' range extended into colder environments.  
     
    “So what we found was that plants before they even confronted the cold, they typically already had skinnier pipes and they already had become herbaceous," she said. "So they responded already to some other pressure. And so maybe it was a dry environment or something like that and that these characteristics, these traits were then really useful for dealing with the cold. So they went into the cold well armed to handle those cold temperatures.”  
     
    Zanne and her team also plan to study plants in warm or dry environments. The study suggests that modern flowering plants, trees and agricultural crops may not have the traitsor the time neededto cope with human-induced climate change.

    You May Like

    Multimedia US Observes Memorial Day With Wreath-laying, National Concert

    Obama lays a wreath at the Tomb of the Unknown Soldier in Arlington Cemetery

    The Strife of the Party: Will Trump Permanently Alter Republicans?

    While billionaire mogul's no-holds-barred style, high-energy delivery are what rocketed him to nomination, they also have created rift between party elites and his supporters

    China's Education Reforms Spark Protest

    Beijing is putting a quota system in place to increase the number of students from poor regions attending universities

    Featured Videos

    Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
    Chinese-Americans Heart Trump, Bucking National Trendi
    X
    May 27, 2016 5:57 AM
    A new study conducted by three Asian-American organizations shows there are three times as many Democrats as there are Republicans among Asian-American voters, and they favor Hillary Clinton over Donald Trump. But one group, called Chinese-Americans For Trump, is going against the tide and strongly supports the business tycoon. VOA’s Elizabeth Lee caught up with them at a Trump rally and reports from Anaheim, California.
    Video

    Video Chinese-Americans Heart Trump, Bucking National Trend

    A new study conducted by three Asian-American organizations shows there are three times as many Democrats as there are Republicans among Asian-American voters, and they favor Hillary Clinton over Donald Trump. But one group, called Chinese-Americans For Trump, is going against the tide and strongly supports the business tycoon. VOA’s Elizabeth Lee caught up with them at a Trump rally and reports from Anaheim, California.
    Video

    Video Reactions to Trump's Success Polarized Abroad

    What seemed impossible less than a year ago is now almost a certainty. New York real estate mogul Donald Trump has won the number of delegates needed to secure the Republican presidential nomination. The prospect has sparked as much controversy abroad as it has in the United States. Zlatica Hoke has more.
    Video

    Video Drawings by Children in Hiroshima Show Hope and Peace

    On Friday, President Barack Obama will visit Hiroshima, Japan, the first American president to do so while in office. In August 1945, the United States dropped an atomic bomb on the city to force Japan's surrender in World War II. Although their city lay in ruins, some Hiroshima schoolchildren drew pictures of hope and peace. The former students and their drawings are now part of a documentary called “Pictures from a Hiroshima Schoolyard.” VOA's Deborah Block has the story.
    Video

    Video Vietnamese Rapper Performs for Obama

    A prominent young Vietnamese artist told President Obama said she faced roadblocks as a woman rapper, and asked the president about government support for the arts. He asked her to rap, and he even offered to provide a base beat for her. Watch what happened.
    Video

    Video Roots Run Deep for Tunisia's Dwindling Jewish Community

    This week, hundreds of Jewish pilgrims are defying terrorist threats to celebrate an ancient religious festival on the Tunisian island of Djerba. The festivities cast a spotlight on North Africa's once-vibrant Jewish population that has all but died out in recent decades. Despite rising threats of militant Islam and the country's battered economy, one of the Arab world's last Jewish communities is staying put and nurturing a new generation. VOA’s Lisa Bryant reports.
    Video

    Video Meet Your New Co-Worker: The Robot

    Increasing numbers of robots are joining the workforce, as companies scale back and more processes become automated. The latest robots are flexible and collaborative, built to work alongside humans as opposed to replacing them. VOA’s Tina Trinh looks at the next generation of automated employees helping out their human colleagues.
    Video

    Video Wheelchair Technology in Tune With Times

    Technologies for the disabled, including wheelchair technology, are advancing just as quickly as everything else in the digital age. Two new advances in wheelchairs offer improved control and a more comfortable fit. VOA's George Putic reports.
    Video

    Video Baby Boxes Offer Safe Haven for Unwanted Children

    No one knows exactly how many babies are abandoned worldwide each year. The statistic is a difficult one to determine because it is illegal in most places. Therefore unwanted babies are often hidden and left to die. But as Erika Celeste reports from Woodburn, Indiana, a new program hopes to make surrendering infants safer for everyone.
    Video

    Video California Celebration Showcases Local Wines, Balloons

    Communities in the U.S. often hold festivals to show what makes them special. In California, for example, farmers near Fresno celebrate their figs and those around Gilmore showcase their garlic. Mike O'Sullivan reports that the wine-producing region of Temecula offers local vintages in an annual festival where rides on hot-air balloons add to the excitement.
    Video

    Video US Elementary School Offers Living Science Lessons

    Zero is not a good score on a test at school. But Discovery Elementary is proud of its “net zero” rating. Net zero describes a building in which the amount of energy provided by on-site renewable sources equals the amount of energy the building uses. As Faiza Elmasry tells us, the innovative features in the building turn the school into a teaching tool, where kids can't help but learn about science and sustainability. Faith Lapidus narrates.

    Special Report

    Adrift The Invisible African Diaspora