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

Katrina Brought Enduring Changes to New Orleans

The city’s recovery is the result of the people and culture the city is famous for, as well as newcomers and start-up industries More

China to Open Stock Markets to Pension Funds

In unprecedented move, government to soon allow local pension funds to invest up to $94 billion in domestic shares More

1 Billion People Used Facebook on Single Day

Facebook CEO Mark Zuckerberg praised the accomplishment in a posting on the social media site 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.
Colombians Flee Venezuela as Border Crisis Escalatesi
X
August 27, 2015 2:08 AM
Hundreds of Colombians have fled Venezuela since last week, amid an escalating border crisis between the two countries. Last week, Venezuelan President Nicolas Maduro ordered the closure of a key border crossing after smugglers injured three Venezuelan soldiers and a civilian. The president also ordered the deportation of Colombians who are in Venezuela illegally. Zlatica Hoke reports.
Video

Video Colombians Flee Venezuela as Border Crisis Escalates

Hundreds of Colombians have fled Venezuela since last week, amid an escalating border crisis between the two countries. Last week, Venezuelan President Nicolas Maduro ordered the closure of a key border crossing after smugglers injured three Venezuelan soldiers and a civilian. The president also ordered the deportation of Colombians who are in Venezuela illegally. Zlatica Hoke reports.
Video

Video Is China's Economic Data Accurate?

Some investors say China's wild stock market gyrations have been made worse by worries about the reliability of that nation's economic data. And some critics say the reports can mislead investors by painting an unrealistically-strong picture of the economy. A key China scholar says Beijing is not fudging ((manipulating)) the numbers, but that the economy is evolving quickly from smoke-stack industries to services, and the ways of tracking new economic activity are falling behind the change. V
Video

Video Next to Iran, Climate at Forefront of Obama Agenda

President Barack Obama this week announced new initiatives aimed at making it easier for Americans to access renewable energy sources such as solar and wind. Obama is not slowing down when it comes to pushing through climate change measures, an issue he says is the greatest threat to the country’s national security. VOA correspondent Aru Pande has more from the White House.
Video

Video Shipping Containers Provide Experimental Housing

Housing prices around the San Francisco Bay area are out of reach for many people, so some young entrepreneurs, artists and tech industry workers are creating their own houses using converted shipping containers. But as VOA's Mike O’Sullivan reports from Oakland, the effort requires ingenuity and dealing with restrictive local laws.
Video

Video Arctic Draws International Competition for Oil

A new geopolitical “Great Game” is underway in earth’s northernmost region, the Arctic, where Russia has claimed a large area for resource development and President Barack Obama recently approved Shell Oil Company’s test-drilling project in an area under U.S. control. Greg Flakus reports.
Video

Video Philippine Maritime Police: Chinese Fishermen a Threat to Country’s Security

China and the Philippines both claim maritime rights in the South China Sea.  That includes the right to fish in those waters. Jason Strother reports on how the Philippines is catching Chinese nationals it says are illegal poachers. He has the story from Palawan province.
Video

Video Technique May Eliminate Drill-and-Fill Dental Care

Many people dread visiting dentists because they're afraid of drills. Now, however, a technology developed by a British firm promises to eliminate the need for mechanical cleaning of dental cavities by speeding a natural process of tooth repair. VOA’s George Putic reports.
Video

Video China's Spratly Island Building Said to Light Up the Night 'Like A City'

Southeast Asian countries claim China has illegally seized territory in the Spratly islands. It is especially a concern for a Philippine mayor who says Beijing is occupying parts of his municipality. Jason Strother reports from the capital of Palawan province, Puerto Princesa.
Video

Video Ages-old Ice Reveals Secrets of Climate Change

Ice caps don't just exist at the world's poles. There are also tropical ice caps, and the largest sits atop the Peruvian Andes - but it is melting, quickly, and may be gone within the next 20 years. George Putic reports scientists are now rushing to take samples to get at the valuable information about climate change locked in the ice.
Video

Video French Experiment in Integrating Roma Under Threat

Plans to destroy France’s oldest slum have sparked an outcry on the part of its Roma residents. As Lisa Bryant reports from the Paris suburb of La Courneuve, rights groups argue the community is a fledgling experiment on integrating Roma who are often outcasts in many parts of Europe.
Video

Video Kenyans Turn to Agriculture for Business

Each year Kenyan universities continue to churn out graduates for the job market despite the already existing high rate of unemployment among youth in the country. Some of these young men and women have realized that agriculture can be as rewarding as any other business or job, and they are resorting to agribusiness in large numbers as a way of tackling unemployment. Rael Ombuor reports for VOA.
Video

Video First Women Graduate Elite Army Ranger School

Two women are making history for the U.S. Army by proving they are among the toughest of the tough. VOA's Carla Babb reports from Fort Benning, Georgia as 94 men and those two women rise as graduates of the difficult Ranger school.

VOA Blogs

More Americas News

Brazil's Rousseff Faces Growing Impeachment Threat

President’s woes increasing as she now also faces angry rival who controls the possibility of impeachment proceedings against her
More

Cancer, Transplant Patients Rail at Drug Shortages in Venezuela

Currency controls, slumping production and smuggling have caused acute shortages of medical supplies in the socialist-led nation
More

Guatemalan Prosecutors Urge President to Resign Amid Scandal

Government comptrollers' office also issued a statement saying Perez Molina should resign 'to avoid greater social unrest that could have unpredictable consequences'
More

Bolt Sprints to Double Gold in Beijing

Jamaican's victories take place on track where in 2008 he first made headlines by winning Olympic gold medals in record fashion at Bird's Nest Stadium
More

Red Cross Makes Plea for Documentation on 'Disappeared'

1980s saw disappearance of thousands of people as consequence of political unrest; disappeared now include people who go missing in natural disasters and wars
More

WFP: Haiti Drought Cuts Harvests, Raises Prices, Food Crisis Looms

Drought has led to acute water shortages, shrivelled harvests and raised food prices, weakening fragile food supply and worsening hunger among poor
More