Quantcast
Science
Rachel Fazio, Black-backed woodpeckers depend on dead trees for food and shelter.

Don’t Get Burned by Misinformation About Dead Trees and Wildfire

By Douglas Bevington

In California, dead trees are big news. In June, the U.S. Forest Service reported that 66 million trees had died since 2010 as the state has experienced a prolonged drought. Drought stress has weakened trees' natural defenses to native bark beetles, resulting in a pulse of tree mortality. Yet amid all of the media coverage of the tree mortality, there has been little mention of the ecological importance of dead trees.


Dead Trees are Vital

Dead trees can remain standing for decades or more and a standing dead tree—known as a "snag"—provides great habitat for wildlife. Birds and mammals make their homes in openings carved within snags, while wood-boring insects that feed on snags provide the foundation of the food chain for a larger web of forest life, akin to plankton in the ocean.

With so much life abounding, it doesn't seem right to call a snag "dead." We commonly associate that word with meaning the end of one's useful life and yet when a tree becomes a snag, it actually reaches a pinnacle of its beneficial role in the ecosystem. In other words, snags are a vital and vibrant part of the forest.

When many snags are created together in what is known as a "snag forest," it produces some of the highest levels of native biodiversity of any forest type. Some forest animals, such as black-backed woodpeckers, depend on finding places with large swaths of snags. Unfortunately for them, unlogged snag forests have become quite rare.

The Deficit of Dead Trees

From the perspective of the timber industry, a snag in the forest is a waste, so timber companies and the Forest Service have spent decades cutting down snags as quickly as possible. As a result, there is now a significant lack of snags in our forests and this shortage is harming woodpeckers, owls and other forest wildlife. For them, the recent pulse of snag creation is good news.

At first glance, 66 million dead trees may seem like a very large number, but it is important to remember that there are 33 million acres of forest in California, so the total effect of the recent pulse of tree mortality has been to add an average of only two snags per acre. To put that number in perspective, forest animals that live in snags generally need at least four to eight snags per acre to provide sufficient habitat and some species require even more snags. For example, California spotted owls use forests with eight to twelve snags to nest and rest and they prefer even higher levels of snags in the areas where they gather their food. And black-backed woodpeckers depend on snag forests with at least several dozen dead trees per acre. These points and many others were addressed in a letter from scientists to California Gov. Brown in February.

Recent tree mortality in the Sierra National Forest.Chad Hanson

Even within areas of high tree mortality, there is a mixture of green trees interspersed with snags. Chad Hanson

Cashing in on Fear of Fire

Despite the ecological benefits from the recent pulse of tree mortality, logging advocates have been eager to cut down the snags. In attempting to sway the public to support large-scale logging, they have not highlighted the wildlife habitat created by these snags or the overall snag deficit, but instead they have stoked fears that dead trees will cause severe wildfires. This claim is generally presented by portraying the trees only as "fuel" for fire. Depicting trees solely as "fuel" is a simplistic and misleading approach that reduces the natural complexity of the forest to a single dimension, resulting in erroneous assumptions about what really occurs.

In fact, dozens of published scientific studies of what actually happens when beetle-affected areas burn show that dead trees do not cause severe fires. One recent study even found that areas with tree mortality burn at lower severity than green tree forests. Dr. Dominick DellaSala of the Geos Institute recently published a synthesis of this research and concluded, "There is now substantial field-based evidence showing that beetle outbreaks do not contribute to severe fires nor do outbreak areas burn more severely when a fire does occur."

The results of the field research are inconvenient for those who try to use tree mortality as a justification for more logging. For example, U.S. Secretary of Agriculture Tom Vilsack, who oversees the Forest Service, made no mention of these studies in his June press release about the California tree mortality. Instead, he falsely claimed that the tree die-offs "increase the risk of catastrophic wildfires" and then he used that claim to lobby for increased funding for his agency.

The biomass power industry in California is also trying to cash in on this fire scare regarding dead trees. Biomass power facilities generate electricity by burning trees and other vegetation. This process is remarkably inefficient, with biomass burning facilities contributing to global warming by emitting more carbon per unit of energy produced than coal or natural gas facilities. (Moreover, in contrast to biomass power, renewable energy sources that don't burn carbon—such as roof-top solar—have no emissions). Biomass power is also economically inefficient, requiring substantial taxpayer and ratepayer subsidies, as well as regulatory loopholes, to keep biomass facilities in business. Thus, the current use of fear of fire to try to justify subsidized logging of snags to fuel biomass facilities is bad news for the climate and taxpayers, as well as for forest ecosystems.

A New Understanding of Forest Diversity

Rather than allowing logging proponents to exploit fear and misinformation about fire, we have a collective opportunity to learn from the current pulse of tree mortality and develop a greater understanding of the full diversity of California's forests. Dead trees, including large patches of snags, are a vital part of the forest. We should appreciate them, along with the natural processes that create them, such as beetles and wildfires. While forest protection efforts have historically focused on green trees, forests come in a variety of colors that also deserve protection, including trees with brown needles and trees with blackened bark. Their diversity provides the basis for a diversity of forest life.

Douglas Bevington is the forest program director for Environment Now and the author of The Rebirth of Environmentalism: Grassroots Activism from the Spotted Owl to the Polar Bear (Island Press, 2009).

Show Comments ()

EcoWatch Daily Newsletter

Sponsored
Climate
In 2018, the Arctic region had the second-lowest overall sea-ice coverage on record. NOAAPMEL / YouTube

The Past 5 Years Were the Arctic's Warmest on Record

The Arctic is still warming at twice the rate of anywhere else on Earth, and the region's air temperatures in the past five years between 2014-2018 have exceeded all previous records since 1900, according to a peer-reviewed report released by the U.S. National Oceanographic and Atmospheric Administration (NOAA) on Tuesday.

The agency's 13th annual Arctic Report Card also concluded that 2018 was second only to 2016 in terms of the region's overall warmth.

Keep reading... Show less
Science
Partial solar eclipse. ndersbknudsen, CC BY 2.0

3 Key Dangers of Solar Geoengineering and Why Some Critics Urge a Global Ban

By Justin Mikulka

A Harvard research team recently announced plans to perform early tests to shoot sunlight-reflecting particles into the high atmosphere to slow or reverse global warming.

These research efforts, which could take shape as soon as the first half of 2019, fall under the banner of a geoengineering technology known as solar radiation management, which is sometimes called "sun dimming."

Keep reading... Show less
Climate
Even an increase of 2°C would cause significant sea level rise. pxhere

Report: Current Climate Policies Will Warm the World by 3.3˚C

This past October, a widely disseminated United Nations report warned that far-reaching and significant climate impacts will already occur at 1.5˚C of warming by 2100.

But in a study released Tuesday, researchers determined that the current climate polices of governments around the world will push Earth towards 3.3˚C of warming. That's more than two times the aspirational 1.5˚C target adopted by nearly 200 nations under the 2015 Paris agreement.

Keep reading... Show less
Food
garett_mosher / iStock / Getty Images

McDonald's to Reduce Antibiotics Use in Beef

In a significant win in the fight to save antibiotics, McDonald's—the largest and most iconic burger chain on the planet—announced Tuesday that it will address the use of antibiotics in its international supply chain for beef by 2021.

Keep reading... Show less
Sponsored
Insights/Opinion
Protesters clashes with riot police on Foch avenue next to the Place de l'Etoile, setting cars ablaze during a Yellow Vest protest on Dec. 1 in Paris. Etienne De Malglaive / Getty Images

The Lesson From a Burning Paris: We Can’t Tax Our Way Out of the Climate Crisis

By Wenonah Hauter

The images from the streets of Paris over the past weeks are stark and poignant: thousands of angry protesters, largely representing the struggling French working class, resorting to mass civil unrest to express fear and frustration over a proposed new gas tax. For the moment, the protests have been successful. French President Emmanuel Macron backed off the new tax proposal, at least for six months. The popular uprising won, seemingly at the expense of the global fight against climate change and the future wellbeing of our planet.

Keep reading... Show less
Popular
Rainbow Mountains in Vinicuna, Perú. Megan Lough / UI International Programs / CC BY-ND 2.0

7 Reasons Why #Mountains Matter

December 11 is International Mountain Day, an annual occasion designated by the United Nations to celebrate Earth's precious mountains.

Mountains aren't just a sight to behold—they cover 22 percent of the planet's land surface and provide habitat for plants, animals and about 1 billion human beings. The vital landforms also supply critical resources such as fresh water, food and even renewable energy.

Keep reading... Show less
Sponsored
Popular
Tetra Images / DigitalVision / Getty Images

Don’t Stress About What Kind of Christmas Tree to Buy, but Reuse Artificial Trees and Compost Natural Ones

By Bert Cregg

Environmentally conscious consumers often ask me whether a real Christmas tree or an artificial one is the more sustainable choice. As a horticulture and forestry researcher, I know this question is also a concern for the Christmas tree industry, which is wary of losing market share to artificial trees.

Keep reading... Show less
Climate
The Woolsey Fire seen from Topanga, California on Nov. 9. Peter Buschmann / Forest Service, USDA

Hotter Planet Makes Extreme Weather Deadlier, New Study Finds

By Jake Johnson

With people across the globe mobilizing, putting their bodies on the line, and getting arrested en masse as part of a broad effort to force the political establishment to immediately pursue ambitious solutions to the climate crisis, new research published on Monday provided a grim look at what the future will bring if transformative change is not achieved: colossal flooding, bigger fires, stronger hurricanes and much more.

Keep reading... Show less
Sponsored

mail-copy

The best of EcoWatch, right in your inbox. Sign up for our email newsletter!