News / Science & Technology

    Tree Deaths Linked to Climate Change

    Aspen, the most widespread tree in North America, is suffering from what scientists call sudden drought-induced death from climate change. (Credit: Kimberly Pham)
    Aspen, the most widespread tree in North America, is suffering from what scientists call sudden drought-induced death from climate change. (Credit: Kimberly Pham)
    Rosanne Skirble
    Hot and dry conditions triggered by climate change are killing the world's trees, according to a new report which examines dozens of scientific articles on the subject.   

    Stanford University graduate student William Anderegg has seen this forest die-off firsthand.

    His doctoral thesis documents the impact of drought on trembling aspen, the most common tree in North America.

    “These are complete hillsides of trembling aspens that are dying off," Anderegg says. "And when the main tree in a forest goes, you tend to see a lot of the other species, especially the grasses and the wild flowers, tend to disappear as well. But you lose a lot of those species from those forests.”  

    Changing ecology

    With colleagues from Stanford and North Arizona State University, Anderegg co-authored the new report which presents a picture of accelerating worldwide tree deaths that appear to be linked to changes in the global climate.

    Tree Die Off Climate Change
    Tree Die Off Climate Changei
    || 0:00:00
    ...    
     
    X


    Anderegg says these changes, triggered by rising levels of heat-trapping gases in the atmosphere, are stressing the world’s forests.

    “One of the ways that we expect climate change to increasingly play out in forests is through these widespread tree mortality events where you stress the trees enough that you essentially push a whole region of them off the edge and in fact what happens afterwards, after a forest dies from drought is every bit as important and in some sense matters more to humans who rely on forests.”

    • Bug infestations like the mountain pine beetle in this lodgepole pine forest in British Columbia, Canada may be in response to a changing climate. Photo credit: Northern Forest Products Association
    • A healthy aspen stand in the San Juan Mountains in western Colorado is at risk as the climate changes. Photo credit: William Anderegg
    • Heat stress kills ponderosa pine in New Mexico. Photo credit: Craig Allen, USGS
    • The sudden Colorado aspen tree die-off near Fairplay, Colorado in 2009 has been linked to climate change. Photo credit: William Anderegg
    • Scientists seek more data to better predict climate impacts on this pinyon pine grove in New Mexico and forests elsewhere around the globe. Photo credit: Craig Allen, USGS
    • Drought triggered this forest die-off in Argentina in 2004. Photo credit: Thomas Kitzberger
    • Forests around the globe are at risk from climate change like this forest die-off in Spain because of a drought. Photo credit: Rafael Navarro-Cerrillo
    • Aspen, the most common tree in North America, is suffering from what scientists call sudden drought-induced death from climate change. Photo credit: Kimberly Pham
    • Scientists are monitoring this grove of Aspen in western Colorado to see how the trees respond to increasingly warmer temperatures. Photo credit: Kimberly Pham


    Trees provide a range of ecological services. They hold soil in place, help purify water and shelter species. They are valued for timber and tourism. When trees die, the ecology and hydrology of a forest change, which in turn promotes insect infestation and fire.

    This can result in long-term shifts in the area’s dominant species and may even trigger a transition to a different ecosystem, such as grass land.

    Devastating consequence

    Anderegg says the most devastating consequence may be that the changing forests, in turn, will start affecting the global climate.  

    “Because forests do a lot to stabilize the climate and to store carbon and when they start to die off, you can actually have forest die-off accelerate climate change," he says. "You get into a vicious cycle.”

    This is especially troubling for Anderegg because trees, which cover 30 percent of the earth’s surface, absorb 25 percent of the climate-changing gases emitted into the atmosphere from cars, buildings and factories.

    Forest monitoring

    While scientists are getting better at tracking the effects of climate change on forests, data is still sparse. Anderegg says his study urges governments and specialists from many disciplines to support wide-scale forest monitoring.  
     
    “It is not just ecologists, but we also need people working with satellites. We need people in government agencies. We need people on the ground to do this as well. It’s unfortunately not something that just the scientific research community can pull off on their own.”
     
    Anderegg, whose research is published in Nature Climate Change, says a better understanding of how climate change is killing off the world’s forests can help shape better forest management, business decisions and policies.

    You May Like

    Syrian Torture Victim Recounts Horrors

    'You make them think you have surrendered' says Jalal Nofal, a doctor who was jailed and survived repeated interrogations in Syria

    Mandela’s Millions Paid to Heirs, But Who Gets His Country Home?

    Saga around $3 million estate of country's first democratic president is far from over as Winnie Mandela’s fight for home overshadows payouts

    Guess Which Beach is 'Best in the US'?

    Hawaii’s Hanauma Bay tops an annual "top 10" list compiled by a coastal scientist, also known as Doctor Beach

    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.
    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