News / USA

    Vines Choking Americas' Forests

    Aggressive, fast-growing vines are structural parasites

    Nearly all vegetation on top of the fallen tree is from the liana Coccoloba parimensis, which can rapidly produce new stems to colonize the forest.
    Nearly all vegetation on top of the fallen tree is from the liana Coccoloba parimensis, which can rapidly produce new stems to colonize the forest.

    Multimedia

    Audio
    Rosanne Skirble

    In the American tropics, thick woody vines called lianas are outpacing trees. They're sucking up soil, nutrients and water, leaving less resources for the trees around them.

    University of Wisconsin plant ecologist Stefan Schnitzer studies these aggressive, fast growing vines known as lianas.

    "They are structural parasites," he says. "They use the architecture of the tree. They climb up the tree, and they put their leaves on top of the tree’s leaves."

    Lianas help animals traverse the forest, escape predators and get food.   

    In the American tropics, the vines are increasing in numbers relative to trees, a trend documented by Schnitzer and colleagues in the journal Ecology Letters.

    "Trees may be increasing or decreasing, but in any given forest lianas are increasing much more. This pattern has finally snapped into focus. We should all believe it now, because this is one of the first large scale structural changes occurring in tropical forests."

    The researchers base their findings on eight studies of lowland tropical and subtropical forests in Central and South America. Schnitzer says a variety of factors could be at play.

    "We think tropical forests in the Americans are drying out a little bit, which would favor liana proliferation. We think that elevated CO2 may also favor liana proliferation, especially under a slightly drier scenario, a drier climate."

    Lianas also recover more quickly from changing land use like logging, and from the seasonal droughts that are becoming more common with global climate change. Schnitzer says more lianas could slow tree growth, accelerate tree death and lessen the amount of carbon a forest absorbs, since vines can’t store as much carbon as the trees they replace.

    "What happens then is tropical forests will stop holding as much carbon in the form of bio-mass or tree trunks because there will be less growth, less carbon fixation and less carbon pulled out of the air, and that carbon will go back into the atmosphere. When that happens, we get additional climate change from elevated CO2 in the atmosphere."

    The data also show that as the parasitic woody vines suck up soil nutrients and water to support their rapid growth, they are leaving less of those resources for their host trees to use. Stefan Schnitzer notes that the pattern he and his colleagues are seeing has not been documented outside of the American tropics.

    The scientists are working with the Smithsonian Tropical Research Institute on large-scale vine removal experiments to better understand the lianas' impact.

    You May Like

    Video Rubio Looks to Surge in New Hampshire

    Republican presidential candidate has moved into second place in several recent surveys and appears to be gaining ground on longtime frontrunner Donald Trump

    UN Calls for Global Ban on Female Genital Mutilation

    Recent UNICEF report finds at least 200 million girls and women alive today have undergone female genital mutilation in 30 countries

    UN Pilots New Peace Approach in CAR

    Approach launched in northern town of Kaga Bandoro, where former combatants of mainly Muslim Seleka armed group and Christian and animist anti-Balaka movement are being paid to do community work

    This forum has been closed.
    Comments
         
    There are no comments in this forum. Be first and add one

    Featured Videos

    Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
    German Artists to Memorialize Refugees With Life Jacket Exhibiti
    X
    Hamada Elsaram
    February 05, 2016 4:30 PM
    Sold in every kind of shop in some Turkish port towns, life jackets have become a symbol of the refugee crisis that brought a million people to Europe in 2015.  On the shores of Lesbos, Greece, German artists collect discarded life jackets as they prepare an art installation they plan to display in Germany.  For VOA, Hamada Elrasam has this report from Lesbos, Greece.
    Video

    Video German Artists to Memorialize Refugees With Life Jacket Exhibit

    Sold in every kind of shop in some Turkish port towns, life jackets have become a symbol of the refugee crisis that brought a million people to Europe in 2015.  On the shores of Lesbos, Greece, German artists collect discarded life jackets as they prepare an art installation they plan to display in Germany.  For VOA, Hamada Elrasam has this report from Lesbos, Greece.
    Video

    Video E-readers Help Ease Africa's Book Shortage

    Millions of people in Africa can't read, and there's a chronic shortage of books. A non-profit organization called Worldreader is trying to help change all that one e-reader at a time. VOA’s Deborah Block tells us about a girls' school in Nairobi, Kenya where Worldreader is making a difference.
    Video

    Video Genius Lets World Share Its Knowledge

    Inspired by crowdsourcing companies like Wikipedia, Genius allows anyone to edit anything on the web, using its web annotation tool
    Video

    Video Former Drug CEO Martin Shkreli Angers US Lawmakers

    A former U.S. pharmaceutical business executive has angered lawmakers by refusing to explain why he raised the price of a life-saving pill by 5,000 percent. Martin Shkreli was removed from a congressional hearing on Thursday after citing his Fifth Amendment right to stay silent. Zlatica Hoke has more.
    Video

    Video Super Bowl TV Commercials are Super Business for Advertisers

    The Super Bowl, the championship clash between the two top teams in American Football, is the most-watched sporting event of the year, and advertisers are lining up and paying big bucks to get their commercials on the air. In fact, the TV commercials during the Super Bowl have become one of the most anticipated and popular features of the event. VOA's Brian Allen has a sneak peek of what you can expect to see when the big game goes to commercial break, and the real entertainment begins.
    Video

    Video In Philippines, Mixed Feelings About Greater US Military Presence

    In the Philippines, some who will be directly affected by a recent Supreme Court decision clearing the way for more United States troop visits are having mixed reactions.  The increased rotations come at a time when the Philippines is trying to build up its military in the face of growing maritime assertiveness from China.  From Bahile, Palawan on the coast of the South China Sea, Simone Orendain has this story.
    Video

    Video Microcephaly's Connection to Zika: Guilty Until Proven Innocent

    The Zika virus rarely causes problems for the people who get it, but it seems to be having a devastating impact on babies whose mothers are infected with Zika. VOA's Carol Pearson has more.
    Video

    Video Solar Innovation Provides Cheap, Clean Energy to Kenya Residents

    In Kenya, a company called M-Kopa Solar is providing clean energy to more than 300,000 homes across East Africa by allowing customers to "pay-as-you-go" via their cell phones. As Lenny Ruvaga reports from Kangemi, customers pay a small deposit for a solar unit and then pay less than a dollar a day to get clean energy to light up their homes or businesses.
    Video

    Video Stunning Artworks Attract Record Crowds, Thanks to Social Media

    A new exhibit at the oldest art museum in America is shattering attendance records. Thousands of visitors are lining up to see nine giant works of art that have gotten a much-deserved shot of viral marketing. The 150-year-old Smithsonian American Art Museum has never had a response quite like this. VOA's Julie Taboh reports.
    Video

    Video Apprenticeships Put Americans on Path Back to Work

    Trying to get more people into the U.S. workforce, the Obama administration last year announced $175 million in grants towards apprenticeship programs. VOA White House correspondent Aru Pande went inside one training center outside of Washington that has gained national recognition for helping put people on the path to employment.
    Video

    Video New Material May Reduce Concussion Effects

    As the 2016 National Football League season reaches its summit at the Super Bowl this coming Sunday (2/7), scientists are trying to learn how to more effectively protect football players from dangerous and damaging concussions. Researchers at Cardiff and Cambridge Universities say their origami-based material may solve the problem. VOA’s George Putic reports.
    Video

    Video Saudi Arabian Women's Sports Chip Away at Stereotypes

    Saudi Arabian female athletes say that sports are on the front line of busting traditions that quash women’s voices, both locally and internationally. In their hometown of Jeddah, a group of basketball players say that by connecting sports to health issues, they are encouraging women and girls to get out of their homes and participate in public life. VOA’s Heather Murdock reports.
    Video

    Video A Year Later, Fortunes Mixed for Syrians Forging New Lives in Berlin

    In April of last year, VOA followed the progress of six young Syrian refugees -- four brothers and their two friends -- as they made their way from Libya to Italy by boat, and eventually to Germany. Reporter Henry Ridgwell caught up with the refugees again in Berlin, as they struggle to forge new lives amid the turmoil of Europe's refugee crisis.
    Video

    Video Zika Virus May be Hard to Stop

    With the Zika virus spreading rapidly, the World Health Organization Monday declared Zika a global health emergency. As Alberto Pimienta reports, for many governments and experts, the worst is yet to come.