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

Ebola Death Toll Nears 5,000 as Virus Advances

West Africa bears heaviest burden; Mali toddler’s death raises new fears More

Jordan’s Role in Fighting IS Carries Domestic Risks

There are Western concerns Islamic State militants soon may unleash offensive in kingdom that could create upheaval - though nation has solid intel, grip on banking system More

Asian-Americans Enter Public Office in Record Numbers

A steady deepening engagement in local politics pays off for politicians like Chinese-American Judy Chu More

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.
After Decades of Pressure, Luxembourg Drops Bank Secrecy Rulesi
X
October 21, 2014 12:20 AM
European Union finance ministers have reached a breakthrough agreement that will make it more difficult for tax cheats to hide their money. The new legislation, which had been blocked for years by countries with a reputation as tax havens, was approved last week after Luxembourg and Austria agreed to lift their vetoes. But as Mil Arcega reports, it doesn’t mean tax cheats have run out of places to keep their money hidden.
Video

Video After Decades of Pressure, Luxembourg Drops Bank Secrecy Rules

European Union finance ministers have reached a breakthrough agreement that will make it more difficult for tax cheats to hide their money. The new legislation, which had been blocked for years by countries with a reputation as tax havens, was approved last week after Luxembourg and Austria agreed to lift their vetoes. But as Mil Arcega reports, it doesn’t mean tax cheats have run out of places to keep their money hidden.
Video

Video Kobani Refugees Welcome, Turkey Criticizes, US Airdrop

Residents of Kobani in northern Syria have welcomed the airdrop of weapons, ammunition and medicine to Kurdish militia who are resisting the seizure of their city by Islamic State militants. The Turkish government, however, has criticized the operation. VOA’s Scott Bobb reports from southeastern Turkey, across the border from Kobani.
Video

Video China Political Meeting Seeks to Improve Rule of Law

China’s communist leaders will host a top level political meeting this week, called the Fourth Plenum, and for the first time in the party’s history, rule of law will be a key item on the agenda. Analysts and Chinese media reports say the meetings could see the approval of long-awaited measures aimed at giving courts more independence and include steps to enhance an already aggressive and high-reaching anti-corruption drive. VOA’s Bill Ide has more from Beijing.
Video

Video US ‘Death Cafes’ Put Focus on the Finale

In contemporary America, death usually is a topic to be avoided. But the growing “death café” movement encourages people to discuss their fears and desires about their final moments. VOA’s Jerome Socolovsky reports.
Video

Video Ebola Orphanage Opens in Sierra Leone

Sierra Leone's first Ebola orphanage has opened in the Kailahun district. Hundreds of children orphaned since the beginning of the Ebola outbreak face stigma and rejection with nobody to care for them. Adam Bailes reports for VOA about a new interim care center that's aimed at helping the growing number of children affected by Ebola.
Video

Video Young Nairobi Tech Innovator on 'Track' in Security Business

A 24-year-old technology innovator in Nairobi has invented a tracking device that monitors and secures cars. He has also come up with what he claims is the most robust audio-visual surveillance system yet. As Lenny Ruvaga reports from the Kenyan capital, his innovations are offering alternative security solutions.
Video

Video Latinas Converting to Islam for Identity, Structure

Latinos are one of the fastest growing groups in the Muslim religion. According to the Pew Research Center, about 6 percent of American Muslims are Latino. And a little more than half of new converts are female. VOA’s Carolyn Presutti travelled to Miami, Florida -- where two out of every three residents is Hispanic -- to learn more.
Video

Video Exclusive: American Joins Kurds' Anti-IS Fight

The United States and other Western nations have expressed alarm about their citizens joining Islamic State forces in Syria and Iraq. In a rare counterpoint to the phenomenon, an American has taken up arms with the militants' Syrian Kurdish opponents. Elizabeth Arrott has more in this exclusive profile by VOA Kurdish reporter Zana Omer in Ras al Ayn, Syria.
Video

Video South Korea Confronts Violence Within Military Ranks

Every able-bodied South Korean male between 18 and 35 must serve for 21 to 36 months in the country’s armed forces, depending upon the specific branch. For many, service is a rite of passage to manhood. But there are growing concerns that bullying and violence come along with the tradition. Reporter Jason Strother has more from Seoul.
Video

Video North Carolina Emerges as Key Election Battleground

U.S. congressional midterm elections will be held on November 4th and most political analysts give Republicans an excellent chance to win a majority in the U.S. Senate, which Democrats now control. So what are the issues driving voters in this congressional election year? VOA National Correspondent Jim Malone traveled to North Carolina, one of the most politically competitive states in the country, to find out.
Video

Video Comanche People Maintain Pride in Their Heritage

The Comanche (Indian nation) once were called the “Lords of the Plains,” with an empire that included half the land area of current day Texas, large parts of Oklahoma, New Mexico, Kansas and Colorado.The fierceness and battle prowess of these warriors on horseback delayed the settlement of most of West Texas for four decades. VOA’s Greg Flakus reports from Lawton, Oklahoma, that while their warrior days are over, the 15,000 members of the Comanche Nation remain a proud people.
Video

Video Turkey Campus Attacks Raise Islamic Radicalization Fears

Concerns are growing in Turkey of Islamic radicalization at some universities, after clashes between supporters of the jihadist group Islamic State (IS) or ISIS, and those opposed to the extremists. Pro-jihadist literature is on sale openly on the streets of Istanbul. Critics accuse the government of turning a blind eye to radicalism at home, while Kurds accuse the president of supporting IS - a charge strongly denied. Henry Ridgwell reports from London.

All About America

AppleAndroid