UC Berkeley has stated that its plan to cut down all blue gum eucalyptus, Monterey pine, and acacia trees in a section of the East Bay hills is the best method for preventing a catastrophic wildfire. But the proposal to cut down 54,000 nonnative trees on about 284 acres in Claremont and Strawberry canyons and a connecting ridge has drawn fierce criticism from residents, most notably a group called the Hills Conservation Network. A MoveOn petition that the group started had gathered some 4,700 signatures as of press time. Yet UC has largely dismissed these opponents as a vocal minority that is simply against cutting trees.
However, a letter obtained by the Express that was written by a respected environmental engineering company challenges several aspects of UC Berkeley's plan. The letter from URS Corporation, which regularly contracts with numerous public agencies and was initially hired to be a consultant on the tree-cutting project, even questions whether UC Berkeley's proposal poses its own fire risk.
In addition, the East Bay Regional Park District is proposing a much less-drastic project than UC Berkeley. The park district is proposing to do "selective thinning" on its land in the East Bay hills, along with the removal of some (but not all) nonnative trees. The stark difference between the park district's plan and that of UC Berkeley, coupled with the letter by URS Corporation, raises questions as to whether UC's plan to cut down all nonnative trees in Claremont and Strawberry canyons is necessary.
According to the letter from URS Corporation, the method of thinning and regularly clearing the understory (which is being used by the park district) was not chosen by UC because of "increased costs and a longer time period to implement." Although the letter stated that thinning and regularly clearing understory (defined as smaller trees and bark) would not be as effective overall at preventing fires as cutting down all the eucalyptus, it "would reduce the fire hazard and would thus meet the purpose and need" of the project. In other words, thinning and clearing would be sufficient to lessen the fire risk in the East Bay hills.
The letter goes on to question the need to cut down all the Monterey pine and acacia trees, stating, "UC inaccurately characterizes the fire hazard risk posed by the two species. ... Monterey pine and acacia trees in the treatment area only pose a substantial fire danger when growing within a eucalyptus forest."
Furthermore, the letter wondered whether UC Berkeley's proposal would actually create a new fire hazard. That's because UC wants to spread chips of the cut trees up to two feet in depth in 20 percent of the project area as a way to prevent nonnatives from growing back and to prevent fires. While acknowledging the fire hazard of eucalyptus trees due to their "high fuel loads in the canopy and on the ground" (because of their shedding bark), the letter noted, "the comparative risk between eucalyptus in the form of a dense standing forest versus the form of a 2-foot-deep mulch layer on the ground is not well documented. Studies have shown that mulch layers actually can pose a fire risk depending upon the type of material, the depth of the mulch, and the climate at the mulch site." It goes on to state that mulches high in oils (as eucalyptus mulch would be) ignite more easily, and that mulch fires in a hot, dry climate (such as that of the East Bay hills) start more readily. URS Corp recommended a mulch layer of "less than 4 inches ... to avoid spontaneous combustion."
East Bay Regional Park District proposes only leaving wood chips at a depth of four to six inches in its plan. The park district, along with UC Berkeley and the City of Oakland, applied for the $5.6 million FEMA grant for fire hazard reduction on a total of about 1,000 acres in the East Bay Hills. In all, the public agencies plan to cut down more than 80,000 trees. Because of the grant application, FEMA is now leading the environmental review process.
According to the letter from URS Corp, UC Berkeley contends that the concern of embers being generated at the site of wood chips is negated in the absence of a canopy. But because UC is removing only nonnative trees, native species such as California bay and coast live oak would remain in the canyons. "Although the fire risk of bay and coast live oak is lower than eucalyptus, the misleading statement about an absent canopy undermines the argument that the risk of embers is eliminated," URS Corp stated.
The remaining vegetation on UC's land would also affect the fire hazard. And URS Corp strongly questioned UC's assumptions about the types of plants and trees that would remain after the proposed clearing.
URS Corp noted that there are two types of fires: climate-driven fires and fuel-driven fires. While the removal of eucalyptus, in particular, would reduce the risk of catastrophic fires driven by climate conditions in the area, the risk of fuel-driven fires is unknown. That's because URS Corp believes that because UC has no plans for re-planting the area, all different types of vegetation may sprout up after the project is completed, including native and nonnative grasslands, chaparral, nonnative shrub/scrub communities, and oak-bay forests. And each one of those vegetation types carry with it different fire conditions. For example, "a chaparral-dominated landscape in the post-treatment project area would create a fire hazard profile with its own suite of risks and concerns for fire protection ...," stated URS.