The best of EcoWatch, right in your inbox. Sign up for our email newsletter!
Importance of Old Growth Forests: Carbon Capture Potential Grows With Age
We know that forests are biodiversity-rich, and we know they provide us with essential ecosystem services, such as regulating water flows and influencing weather patterns. One ecosystem service often discussed these days is the role of forests in helping regulate the amount of the greenhouse gas—carbon dioxide (CO2)—in the atmosphere. A new analysis in Nature, one of the top scientific journals, demonstrates that big, mature trees play an important part in this role.
Photo courtesy of Shutterstock
Forests store large amounts of carbon that would otherwise contribute to climate change. They store nearly 300 billion tons of carbon in their living parts (biomass)—roughly 30 times the annual amount of emissions created by burning fossil fuels. But when forests are degraded or destroyed, this carbon is released into the atmosphere.
It used to be thought that only young forests captured (or sequestered) carbon from the atmosphere whilst they were growing, and that ancient (also called primary or old-growth) forests simply stored this carbon. However, several recent studies have now shown that intact ancient forests also take up carbon from the atmosphere¹. This new study could help explain how ancient forests continue to take up carbon.
The researchers have found that carbon uptake of trees (as measured by growth rates) continuously increases with their size because the overall leaf area increases as they grow. This enables bigger trees to absorb more carbon from the atmosphere. Thus, the oldest trees in a forest capture the most carbon from the atmosphere. These oldest trees are to be found in ancient forests. Importantly, older trees are also more valuable for biodiversity than younger trees because they support a wider range of species. For example, hollows and snags provide habitats for nesting birds.
The authors warn, however, that forest dynamics are complex: large trees are subject to higher mortality rates than young trees and the number of trees in a given area may be higher in a young forest. These factors may offset the increased growth of mature trees in a forest. Nonetheless, it is now evident that big, old trees are highly important components of ancient forests, in terms of biodiversity and both carbon uptake and storage.
Selective logging in forests usually removes the bigger trees, and much deforestation occurs in ancient forests, which contains these older trees. This new study emphasises the double whammy of removing these trees: removal releases carbon into the atmosphere where it contributes to climate change, but also removes an important sink that would take up some of mankind's carbon emissions from the atmosphere. That’s why Greenpeace is campaigning for zero (gross) deforestation, globally, by 2020.
¹ Stephens et al. 2007. Science 316: 1732-1735; Luyssaert et al. 2008. Nature 455: 213-215; Lewis 2009. Nature 457: 1003-1007.
Visit EcoWatch’s BIODIVERSITY page for more related news on this topic.
EcoWatch Daily Newsletter
By Jennifer Molidor, PhD
Climate change, habitat loss and pollution are overwhelming our planet. Thankfully, these enormous threats are being met by a bold new wave of environmental activism.
Trump Makes Strange Claim About Water Efficient Toilets: 'People Are Flushing Toilets 10 Times, 15 Times'
President Donald Trump mocked water-efficiency standards in new constructions last week. Trump said, "People are flushing toilets 10 times, 15 times, as opposed to once. They end up using more water. So, EPA is looking at that very strongly, at my suggestion." Trump asked the Environmental Protection Agency (EPA) for a federal review of those standards since, he claimed with no evidence, that they are making bathrooms unusable and wasting water, as NBC News reported.
By Carey Gillam
Former Monsanto Chairman and CEO Hugh Grant will have to testify in person at a St. Louis-area trial set for January in litigation brought by a cancer-stricken woman who claims her disease was caused by exposure to the company's Roundup herbicide and that Monsanto covered up the risks instead of warning consumers.
A powerful volcano on Monday rocked an uninhabited island frequented by tourists about 30 miles off New Zealand's coast. Authorities have confirmed that five people died. They expect that number to rise as some are missing and police officials issued a statement that flights around the islands revealed "no signs of life had been seen at any point,", as The Guardian reported.
"Based on the information we have, we do not believe there are any survivors on the island," the police said in their official statement. "Police is working urgently to confirm the exact number of those who have died, further to the five confirmed deceased already."
The eruption happened on New Zealand's Whakaari/White Island, an islet jutting out of the Bay of Plenty, off the country's North Island. The island is privately owned and is typically visited for day-trips by thousands of tourists every year, according to The New York Times.
My god, White Island volcano in New Zealand erupted today for first time since 2001. My family and I had gotten off it 20 minutes before, were waiting at our boat about to leave when we saw it. Boat ride home tending to people our boat rescued was indescribable. #whiteisland pic.twitter.com/QJwWi12Tvt— Michael Schade (@sch) December 9, 2019
Michael Schade / Twitter
At the time of the eruption on Monday, about 50 passengers from the Ovation of Seas were on the island, including more than 30 who were part of a Royal Caribbean cruise trip, according to CNN. Twenty-three people, including the five dead, were evacuated from the island.
The eruption occurred at 2:11 pm local time on Monday, as footage from a crater camera owned and operated by GeoNet, New Zealand's geological hazards agency, shows. The camera also shows dozens of people walking near the rim as white smoke billows just before the eruption, according to Reuters.
Police were unable to reach the island because searing white ash posed imminent danger to rescue workers, said John Tims, New Zealand's deputy police commissioner, as he stood next to Prime Minister Jacinda Ardern in a press conference, as The New York Times reported. Tims said rescue workers would assess the safety of approaching the island on Tuesday morning. "We know the urgency to go back to the island," he told reporters.
"The physical environment is unsafe for us to return to the island," Tims added, as CNN reported. "It's important that we consider the health and safety of rescuers, so we're taking advice from experts going forward."
Authorities have had no communication with anyone on the island. They are frantically working to identify how many people remain and who they are, according to CNN.
Geologists said the eruption is not unexpected and some questioned why the island is open to tourism.
"The volcano has been restless for a few weeks, resulting in the raising of the alert level, so that this eruption is not really a surprise," said Bill McGuire, emeritus professor of geophysical and climate hazards at University College London, as The Guardian reported.
"White Island has been a disaster waiting to happen for many years," said Raymond Cas, emeritus professor at Monash University's school of earth, atmosphere and environment, as The Guardian reported. "Having visited it twice, I have always felt that it was too dangerous to allow the daily tour groups that visit the uninhabited island volcano by boat and helicopter."
The prime minister arrived Monday night in Whakatane, the town closest to the eruption, where day boats visiting the island are docked. Whakatane has a large Maori population.
Ardern met with local council leaders on Monday. She is scheduled to meet with search and rescue teams and will speak to the media at 7 a.m. local time (1 p.m. EST), after drones survey the island, as CNN reported.
- New Evidence Suggests Ancient Egypt Was Brought Down by ... ›
- Climate Change Could Set Off Volcanoes - EcoWatch ›
- U.S. Has 18 'Very High Threat' Volcanoes - EcoWatch ›
- Scientists Discover 91 Volcanoes Hidden Under Antarctic Ice Sheet ... ›