News / Americas

Vines Overwhelming Trees in Rain Forests

Multimedia

Zulima Palacio

Tropical rain forests in the American Hemisphere and other regions of the world are changing rapidly.  Studies conducted over recent decades indicate that increasingly, most of the trees in South and Central American rain forests must compete for light and nutrients with "lianas" or woody vines.  Studies also show that lianas are growing so abundant as a result of climate change and higher levels of carbon dioxide in the atmosphere that they are overwhelming their host trees, and in some cases, killing them.

Deep in the tropical forest of Panama, on the island known as Barro Colorado, scientists from the Smithsonian Tropical Research Institute have been studying the flora and fauna for nearly 100 years.

Stefan Schnitzer is one of those scientists. He studies "lianas" or woody vines, structural parasites that require trees for support.  He found out that vines growing on tree crowns have more than doubled over the last four decades.

"What we found is that probably about 80 percent of the trees that are around us now have some competition with vines," Schnitzer noted.  "Vines are affecting nearly all of the trees. So most of their growth rate is being reduced because of vines."

Not only growth.  Lianas compete for nutrients in the soil, deprive trees of light, and can choke and kill them.

"You can call them natural born killers," Schnitzer added.  "What's very interesting about these lianas is they climb up a tree, that tree falls, the liana falls with it, but the tree dies and the liana stays alive."  

Schnitzer estimates that some lianas are hundreds of years old, cover dozens of trees at one time and stretch for nearly a kilometer over tree tops.  

Although some lianas produce fruits and habitat for animals, they are devastating for most trees.  One liana we found had more than 10 different rooting points within a few square meters.

"This is an enormous liana and it's rooted right there next to the tree; it's competing for all sorts of resources," Schnitzer explained.  "And then, to add insult to injury, it's sending this giant stem up into the canopy where is competing for light as well."  

Schnitzer says he believes lianas are growing faster because of drought and warmer temperatures. He says these woody vines prevent trees from growing and capturing carbon dioxide.  

In another clearing we saw, there were no trees, the vines had completely taken over.

"What you get is tree gaps that never recover or take them 20-30 years to recover back to full canopy, because there are so many lianas preventing trees from growing," Schnitzer said.

Schnitzer and his team are also working on the nearby peninsula of Gigante in another protected area.  Here, hundreds of tree seedlings from 14 native species are ready to be planted.  

Schnitzer's team will plant these seedlings in 16 plots, half with lianas and half without them.

"We will measure mortality or survival every 2-3 months, and then we measure growth every 6 to 12 months. And after two or three years we'll know which tree species are going to regenerate better when lianas are present versus when lianas are absent," Schnitzer explained.

At the end of 20 years, Schnitzer says they will know how the tropical forest is changing and how to restore and conserve it.

"The forests are changing and moving in a direction that may result in more liana- dominated forest and forests dominated by trees that can tolerate lianas," Schnitzer said.

Why should we care? Because, Schnitzer says, tropical forests contain about one third of all global terrestrial carbon.  Without trees to capture that carbon dioxide, global climate change would be an even greater threat.

You May Like

Video VOA EXCLUSIVE: Iraq President Vows to Fight IS 'Until They Are Killed or We Die'

In wide-ranging interview with VOA Persian service reporter, Fuad Masum describes conflict as new type of fight that will take time to win More

Video Russian Anti-Corruption Campaigner Slams Putin’s Crackdown on Dissent

In interview with VOA Alexei Navalny says he believes new law against 'undesirable NGOs' part of move to keep Russian president in power More

Video On The Scene: In Ethiopia, 'Are You a Journalist?' Is a Loaded Question

VOA's Anita Powell describes the difficulties faced by reporters in fully conveying the story in a country where people are reticent to share their true opinions 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.
Expelled from Pakistan, Afghan Refugees Return to Increased Hardshipi
X
Ayesha Tanzeem
May 28, 2015 6:48 PM
Undocumented refugees returning to Afghanistan from Pakistan have no jobs, no support system, and no home return to, and international aid agencies say they and the government are overwhelmed and under-resourced. Ayesha Tanzeem has more from Kabul.
Video

Video Expelled from Pakistan, Afghan Refugees Return to Increased Hardship

Undocumented refugees returning to Afghanistan from Pakistan have no jobs, no support system, and no home return to, and international aid agencies say they and the government are overwhelmed and under-resourced. Ayesha Tanzeem has more from Kabul.
Video

Video Britain Makes Controversial Move to Crack Down on Extremism

Britain is moving to tighten controls on extremist rhetoric, even when it does not incite violence or hatred -- a move that some are concerned might unduly restrict basic freedoms. It is an issue many countries are grappling with as extremist groups gain power in the Middle East, fueled in part by donations and fighters from the West. VOA’s Al Pessin reports from London.
Video

Video Floodwaters Recede in Houston, but Rain Continues

Many parts of Texas are recovering from one of the worst natural disasters to hit the southwestern state. Heavy rains on Monday and early Tuesday caused rivers to swell in eastern and central Texas, washing away homes and killing at least 13 people. As VOA’s Greg Flakus reports from Houston, floodwaters are receding slowly in the country's fourth-largest city, and there likely is to be more rain in the coming days.
Video

Video 3D Printer Makes Replica of Iconic Sports Car

Cars with parts made by 3D printers are already on the road, but engineers are still learning about this new technology. While testing the possibility of printing an entire car, researchers at the U.S. Department of Energy recently created an electric-powered replica of an iconic sports roadster. VOA’s George Putic has more.
Video

Video Al-Shabab Recruitment Drive Still on In Kenya

The al-Shabab militants that have long battled for control of Somalia also have recruited thousands of young people in Kenya, leaving many families disconsolate. Mohammed Yusuf recently visited the Kenyan town of Isiolo, and met with relatives of those recruited, as well as a many who have helped with the recruiting.
Video

Video US Voters Seek Answers From Presidential Candidates on IS Gains

The growth of the Islamic State militant group in Iraq and Syria comes as the 2016 U.S. presidential campaign kicks off in the Midwest state of Iowa.   As VOA’s Kane Farabaugh reports, voters want to know how the candidates would handle recent militant gains in the Middle East.
Video

Video A Small Oasis on Kabul's Outskirts Provides Relief From Security Tensions

When people in Kabul want to get away from the city and relax, many choose Qargha Lake, a small resort on the outskirts of Kabul. Ayesha Tanzeem visited and talked with people about the precious oasis.
Video

Video Film Festival Looks at Indigenous Peoples, Culture Conflict

A recent Los Angeles film festival highlighted the plight of people caught between two cultures. Mike O'Sullivan has more on the the Garifuna International Film Festival, a Los Angeles forum created by a woman from Central America who wants the world to know more about her culture.
Video

Video Kenyans Lament Losing Sons to al-Shabab

There is agony, fear and lost hope in the Kenyan town of Isiolo, a key target of a new al-Shabab recruitment drive. VOA's Mohammed Yusuf visits Isiolo to speak with families and at least one man who says he was a recruiter.
Video

Video Scientists Say Plankton More Important Than Previously Thought

Tiny ocean creatures called plankton are mostly thought of as food for whales and other large marine animals, but a four-year global study discovered, among other things, that plankton are a major source of oxygen on our planet. VOA’s George Putic reports.
Video

Video Kenya’s Capital Sees Rise in Shisha Parlors

In Kenya, the smoking of shisha, a type of flavored tobacco, is the latest craze. Patrons are flocking to shisha parlors to smoke and socialize. But the practice can be addictive and harmful, though many dabblers may not realize the dangers, according to a new review. Lenny Ruvaga has more on the story for VOA from Nairobi, Kenya.
Video

Video Iowa Family's Sacrifice Shaped US Military Service for Generations

Few places in America have experienced war like Waterloo. This small town in the Midwest state of Iowa became famous during World War II not for what it accomplished, but what it lost. As VOA’s Kane Farabaugh reports, the legacy of one family’s sacrifice is still a reminder today of the real cost of war for all families on the homefront.

VOA Blogs

More Americas News

Nazi War Crimes Suspect Dies in Canada

Vladimir Katriuk, 93, had denied allegations that he took part in killings of civilians in Soviet village of Khatyn, now part of Belarus
More

Allies, Ex-players, Fans Abroad Cheer US Move Against FIFA

Soccer devotees flood Twitter with praise, ask why countries with richer traditions in the sport had ignored suspicions of corruption for so long
More

Soccer Great Pele to Join New York Cosmos on Cuban Trip

Goodwill mission will include exhibition match between Cosmos, Cuban national team
More

Researchers: No Foul Play in Death of Chilean Poet Neruda

Chilean government reopened investigation into Neruda's death in January, with new tests designed to look for protein damage caused by poisoning
More

US Senator: Momentum Growing to Lift Sanctions on Cuba

Sen. Tom Udall led a delegation of four Democratic lawmakers to Havana
More

Latin American Soccer Fans Cheer FIFA Corruption Sweep

Latin American fans have long booed officials assumed to be on the take, amid deep public disgust at graft in the game
More