The ground is muddy. Still, both documents say there is a fire hazard. The tree sheds bark and dead leaves, which make a perfect pile of tinder under the tree too. “They’re absolutely dangerous plants,” he says. Relative humidity is in the low teens, and any moisture hidden in the debris below the trees has long wicked away. Grade: 2-3: Eucalyptus: Eucalyptus: Allow to season well since the wood is very wet (sappy) when fresh. On hot days in Tasmania and blue gum’s other native regions, eucalyptus oil vaporizes in the heat. The air begins to smell of fresh sawdust. He says the FEMA plan ignores both the task force’s findings and good sense—that removing the trees would actually make the hills more liable to burn, as exemplified by this field, once covered in blue gums, now thick with grass and thistles. Although the view didn’t change, I saw something different each time through the eyes of the person I was with. “If the plan says ‘thin eucalyptus,’ then that’s what I have to do,” he says. 5 years ago. Eucalyptus Firewood. Its native decomposers are missing too, meaning fallen leaves and bark decay slower than usual; here, eucalyptus groves can accumulate 30 tons of debris or more per acre. The roughly two dozen Australian and American wildfire experts, eucalyptus experts, and fire ecologists I communicated with while reporting this story (the majority of them with no personal connection to the local debate) were unanimous in their verdict: Blue gum eucalyptus is especially, dangerously flammable. “I love eucalyptus,” Bowman says. But then they catch on fire.” The gums are mottled tan and brown like chicken bones, crowded together, the spaces between them choked with brush and hung with streamers of bark. We drive next to Signpost 29, for another view of the possible future. A traditional aboriginal remedy, eucalyptus is a powerful antiseptic used all over the world for relieving coughs and colds, sore throats and other infections. It looks scrubby and multitextured compared to the stand of blue gum across the road. Grass also earns a 1, while oak/bay woodland earns a 6 and scrub vegetation earns a 4 to 8. In the middle of June, I attended a protest outside the Sierra Club’s national headquarters in downtown Oakland. “Save the eucs because they’re great!”. Lots of people are familiar with Eucalyptus as an ingredient in cold remedies like Vicks VapoRub. Oil has a higher energy density and lower ignition point than cellulose (the stuff plant cell walls and Mini Wheats are made of), and in a hot fire, these oils can boil out of the leaf and then ignite, which is why blue gums have a reputation for exploding. In many parts of the state, people planted eucalyptus for that express purpose; the wind inside a forest might have less than half the wind speed it would in the open. Ross Bradstock, a wildfire expert at the University of Wollongong, says that while being able to empirically compare the flammability of different trees would be useful, it’s not currently possible. We walk uphill along Claremont Avenue, then hike up into the eucalyptus grove. By his reading, everything good about the eucalyptus across the street is matched or exceeded by the native species on this side: The native species are less flammable, use less water, collect fog, block wind, and provide more valuable habitat. You get away from stress, smell the smells, see the birds. On the other side of the debate, the Bay Area’s many native plant advocates have their own long list of complaints, also mostly separate from the debate about the trees’ flammability. The state’s first planting of eucalyptus was made by William G. Walker at his Golden Gate Nursery at Fourth and Folsom Streets, San … Though the fire started in grass, the trees were blamed for the severity of the disaster, by some estimates contributing almost three-quarters of the fire’s energy. Eucalyptus oil is sometimes referred to as ‘fever oil’, so that’s something of a clue as to how useful it is for combating fevers! We stop at a turnout and hike up a path through tall grass that opens into a field. Eucalyptus oil and fire are a match made in heaven from the fire’s perspective but a nightmare for those of us in its path. Kent and I walk the same path that I took with Grassetti and Maloney. From unclear comparisons of leaf chemistry, we are led down progressively less rewarding or elucidating scientific rabbit holes. Some wood fires reach heats as high as 1600 degrees Fahrenheit. White Oak is a great firewood for holding a fire overnight. Share your love of Bay Area nature with a Bay Nature gift subscription and save over 30%! This is Gallup’s favorite part of the job, he says—choosing which trees to remove, which trees to keep. But the thing that’s most concerning is the volume of material it can produce.” But, as with the BTU comparisons, there are few applicable apples-to-apples (or blue-gums-to-bay-laurels) studies of ignitability in the Bay Area. “The forests are beautiful. Make eucalyptus tea with 1/4 tsp of dried, crumbled eucalyptus leaves in paper tea bags and infuse it in a cup of boiling water. Scientists speculate that flammable eucalyptus trees evolved to be “fire friendly.” Rapidly catching fire until there is no obvious tinder allows the plant to retain most of its trunk when fire moves on to find more to burn. Here, the debate about the flammability or fire danger of an entire forest is reduced to its smallest, most arcane variables, starting with leaf chemistry. When the wind stirs the boughs, drops of last night’s fog rain down on us. Second, Maloney says removing the eucalyptus would also remove windbreaks.. I met him that morning at the park district fire station at the edge of Tilden Regional Park, and we’ve driven together into the park, stopping first at this overlook along Grizzly Peak Boulevard. They call the eucs bad neighbors. Header illustrations by Jane Kim, InkDwell, Bay Nature Institute It did not offer an explanation. Ignitability—how easily something catches fire—is a combined result of its architecture, chemistry, moisture content, and caloric values. After a fire, many eucalypt species will sprout epicormic shoots along their entire trunks. In the same way that blowing on a campfire will rouse the coals, wind increases the amount of oxygen to a fire and hastens its spread. There is an art to it, he says. Eucalyptus Oil. Trees near the ridgeline can collect inches of fog-drip a year, sometimes even rivaling the amount they might collect from rainfall. The grove is one of those that were logged off after the 1972 freeze, and the trees grew back just a few feet apart, hung with bark and knee-deep in fallen leaves, bark, and twigs. We’re deep in Tilden Regional Park, standing on a fire road between a feller buncher and a chipper. General Information: Eucalyptus is native from Australia, where it comprises more than 75% of all trees. We turn a corner and stop between a feller buncher (which both fells trees and gathers them into bunches) and a chipper. Yet Rice, who helped plan UC Berkeley’s portion of the FEMA application, says that factor is mitigated by the higher moisture content of bay laurel leaves. One bolt of lightning or a careless cigarette and the forest can easily become an inferno. When a tree dies, dozens of new ones appear. It naturally resists the influence of moisture because of the high oil content it naturally contains. To the Sioux of The Dakotas and the Cree, the first new moon of the new year is known, in various dialects, as the "Moon of the Cold-Exploding Trees".. Tree sap is a supercooled liquid in cold temperatures. This is another of blue gums’ talents—its bark makes ideal braziers. White Oak is a great firewood for holding a fire overnight. Variables that determine the temperature of a wood fire include the wood species and the water content of the wood before … This accelerates the eucalyptus fire hazards in a region and discourages firefighting efforts. Many of the hills on the east side of the Caldecott Tunnel are covered in grass, speckled with drooping oak, much as the landscape above Berkeley and Oakland would’ve looked before Oakland developer Frank Colton Havens planted them with eucalyptus. Eucalyptus oil has some healing properties, but its greatest benefit for first or second-degree burns is its cooling ability. So did you really get a net fuel reduction? A UC press release stated that the fire hazard mitigation work in Strawberry and Claremont canyons “will be delayed for an indefinite period.”, Zach St. George, a freelance reporter in Baltimore, is the author of The Journeys of Trees: A Story About Forests, People, and the Future. I asked her why the consortium gave blue gum a high ignitability rating as well as a high hazard rating—what studies was that based on? “We’re trying to change fire behavior,” he says, “to make it easier to put the fire out, to give people more time to evacuate.”. Sign up today: Letter to the Editor: Protecting Diversity Is the Opposite of Xenophobia, Letter from the Publisher: Rethinking Eucalyptus, How the Australian Eucalyptus Came to the East Bay Hills. The eucalyptus tree, native to Australia, and now common in other parts of the world, is an exotic-looking and aromatic tree. That stuff”—the brush—“is going to expand here. The ground below this tree is littered with its rooster-tail leaves and cinnamon-stick tubes of bark. This is because the eucalyptus has displaced natives and it changes soil composition where it grows, altering other life forms as it does so. It’s still messy, a sculpture only half done. It kills germs and stops infections from forming. Eucalyptus is a shrubby, flowering plant with a fresh and herbaceous fragrance. “Anybody who wants to encourage really flammable plants in an urban mix has to do it with their eyes open,” David Bowman told me. They are also found in Australia, of which many are native. Gallup, who has gray hair and thin-frame glasses, is dressed head-to-toe in navy and wears black leather fire boots. It wasn’t based on any specific studies, she told me, but was rather an agreement among the experts—as she recalled it, a sort of, “This is what we think. To find out where that rating came from, I followed a twisted path from document to document, each taking me a little further back in time. Now the flames on the ground are 30 feet high and even higher off the boughs, roaring like a jet engine. In the early 2000s, UC Berkeley and the nonprofit Claremont Canyon Conservancy cleared 70-odd acres on the south side of Claremont Avenue. email@example.com. Berkeley, CA 94710 “We’re in our infancy in understanding how flammability can be practically measured and scaled up,” he says. It might look bad for a while, but with proper management nonnative grasses and brush would be replaced in a decade or two in most areas by native trees, he says. These beautiful stately trees are filled with aromatic oil, which makes them highly combustible. Eucalyptus grow right across the Australian continent, from the arid to the cold sub-alpine regions. But not today. As a result of climate change and rising temperatures, the risk of forest fires grows accordingly. “Eucalyptus is flammable,” says Scott Stephens, a UC Berkeley fire ecologist.