BioCycle January 2004, Vol. 45, No. 1, p. 22
Deadly wildfires last October in Southern California heightened awareness of the fire threat that exists in the forests of western North America. Bark beetles have received much of the blame for the fire-prone state of the forests. However, the cause is actually the combined effects of drought, insects, fire suppression and land management policies. This condition has generated warnings for several years (a state of emergency was declared in March 2003), and efforts to address the problem have been in motion for some time. Still, because of their devastation, the recent fires have given the situation new urgency. Activities are being stepped up to clear the dead wood from areas susceptible to catastrophic fires, including mountain communities, utility right-of ways and national forests.
There is no quick fix to the current problem. It has been many years in the making. It will take many years to remedy. The enormous quantity of wood and brush to be removed will create a huge residuals management challenge. How can this large amount of residuals, of varying qualities, be put to beneficial use with a minimum of waste? In the short run, the residuals could overwhelm the current outlets and markets for wood residuals in the forested localities. In the long run, new ventures will be needed to absorb the influx of wood. Officials are exploring and pursuing options for using the wood to produce lumber, pallets, firewood, compost, mulch, biomass fuel, landfill cover, pulp wood and raw products for export.
Impact Of The Bark Beetles Infestation
Bark beetles have gained a high profile in the current forestry crisis. Explains Pat Paswater of the California Integrated Waste Management Board (CIWMB): “The bark beetle species associated with the Southern California infestation (e.g., the engraver beetle, the western pine beetle and the red turpentine beetle) are endemic to this region. One or more bark beetle species can be responsible for the death of a tree due to successful attacks, mating and offspring development under the bark of the attacked tree. The tree dies and the beetles move on to attack other trees.” In addition to weakening or killing the trees, the beetles can spread a fungus that leaves a blue stain and reduces the quality of the wood for lumber.
Prior to the recent wildfires, over 600,000 acres of Southern California forest were estimated to be infested with exploding bark beetle populations that are killing conifers at an alarming rate. About 50,000 acres in the tree mortality zones of San Bernardino, Riverside and San Diego County burned during the October wildfires according to the California Department of Forestry and Fire Protection (CDF). Vast acres of dead trees in these counties still remain and need to be addressed.
It is important to understand the multitude of factors that contributed to the fire hazard. Healthy trees rely on the availability of water and nutrients to repel individual beetle attacks. When a beetle attacks a healthy tree, it exudes resin, literally pushing the beetle out. Bark beetles act as a natural thinning force of nature by attacking stressed trees. According to Paswater, “Vegetation in Southern California has been continually stressed during four years of drought. Tree overcrowding in these forests is in part a result of the minimal brush thinning and unwavering fire suppression in national forests for many years. The high density of trees has compounded the stress on each tree because it competes for limited water and nutrients. Until southern California receives two or three consecutive years of normal rainfall, there will be no apparent relief from continued beetle attack or additional tree mortality.”
Defueling The Forests
The immediate need is to reduce the amount of fuel in the forests available to a potential fire. The most prominent fuel is the accumulation of dead trees killed by beetles and/or drought. Other fuel is contained in the dense stands of live trees and brush that have developed in the absence of thinning from harvests and fires. However, the magnitude of the task is enormous. In Southern California alone, it is estimated that over 600,000 acres of forested land will have to be restored to a healthy state. Even more land may have to be treated to reestablish healthy ecosystems. This cannot be done in a year, or even a few years so the task must be accomplished in stages and according to priorities.
In the short term, the priority is safety. The areas that are receiving the primary attention include land surrounding communities and houses, areas along fire evacuation routes and power line rights of way. The California Public Utilities Commission has required Southern California Edison (SCE) and other utilities to take steps to prevent trees from falling on power lines, not only to continue service in the event of a fire but also to reduce the possibility that a tree falling on the power line may cause a fire.
Communities and the private landowners in high priority areas also are being required to remove dead and dying trees, generally at their own cost. However, assistance is being offered as much as possible. For instance, San Bernardino County has instituted a “block tree removal” program. Blocks of residential property in high priority fire areas are established and a tree removal contractor is secured for an entire block, at a much lower cost than the properties owners could obtain individually. Counties are also at work cutting trees along evacuation corridors and fire breaks to protect vulnerable communities.
While state and national forest agencies are active in the current projects and policy making, they will play a larger role in the long term forest restoration picture. Bill Snyder, Deputy Director with the California Department of Forestry (CDF), believes that the strategy will center on overall forest health. “In general, reducing the long-term fire threat of wildfires will become an ecosystem issue,” says Snyder. It will involve difficult policy choices that may be controversial, like how much harvesting and fire suppression to allow in the public forests. Success may ultimately depend on uncontrollable factors. “The drought is the big question mark,” notes Snyder. “It will take three or four successive years of good rainfall to rejuvenate the trees so that they can ward off the beetle infestation.”
Good Uses For Good Wood
The forest residuals being removed for the sake of fire protection range from timber-sized trees to limbs and brush. The possible uses for these varied residuals are equally broad, from furniture to mulch. Ideally, the material is sorted such that each component finds its highest end use —lumber grade logs are used for lumber and small limbs and branches are chipped for mulch, compost or fuel. There is no shortage of possibilities, but what is usually in short supply are local outlets that can use the material beneficially. Most forested areas lack the infrastructure required to economically handle the large amount wood expected.
Approximately 500 tons per day (tpd) of chipped material are being produced at the Heaps Peak transfer station near Lake Arrowhead. Due to the fire situation, the facility is operating under an emergency waiver of its permit, handling 100 tpd more than the permit allows. Peter Wulfman, manager for the San Bernardino County solid waste division, estimates that the County’s landfills are taking 200 to 300 tpd of the chips for both alternative daily cover and erosion control on the landfill slopes. Another 150 tpd of chips are going to the Colmac biomass-to-energy facility in Mecca, CA . According to Wulfman, a few composting facilities in the area are taking an average of 50 tpd of chips for use as bulking agents.
Directly to the south, Riverside County is dealing with a similar glut of beetle-ravaged wood, and also is pursuing outlets for the wood opportunistically. For example, the County has contracted with Viramontes Express to establish a temporary grinding station at the old landfill in the mountain community of Idyllwild. At this location, Viramontes Express produces more than 6,000 tons of chipped material monthly, using a 800 hp industrial tub grinder (Diamond Z model 1260). According to Henry Viramontes, the company’s principal owner, this grinder is capable of processing logs up to 80 inches in diameter and ten ft. long, and it can grind whole logs at a rate of 60 tons per hour (100 tons per hour for mixed brush and branches). Operators load the grinder with a front end loader equipped with a rake bucket for handling the logs and brush.
Screens are changed to produce chips from one to four inches, depending on the customer. After the fines are removed via a Morbark trommel screen, a portion of the chips are sent to the Colmac biomass-to-energy facility. The remaining chips and fines are trucked to another Viramontes Express facility in Corona, CA. Here, the chips and fines are further screened, amended with nitrogen, piled and allowed to self-heat for up to 48 hours. The facility is permitted as a “chipping and grinding” facility and under California regulations must move product off the site within 72 hours of receiving the feedstock. Viramontes Express sells this and other materials processed at this site as mulch, bark, wood chips and soil amendment to various customers including the Scott’s Company and several biomass-to-energy plants.
Despite its potential values, a considerable portion of the wood coming out of the forests cannot be processed quickly enough. Long-term storage is not currently an option. Therefore, San Bernardino County has set up three air curtain “destructors” near mountain communities. These destructors are aptly named as the wood is incinerated quickly, at roughly seven tons per hour, using high velocity air stream without capturing energy. The three incinerators together are disposing of 450 tons of beetle-damaged wood per day, operating at 24 hours per day, six days per week.
Fortunately, public officials are not satisfied with seeing the wood go up in flames without benefit. According to Paswater, “CIWMB staff are working with federal, state and local government representatives to identify intermediate and long-term possibilities for the dead conifers. Grants from CDF and U.S. Forest Service (USFS) have brought portable milling equipment into the area to produce lumber that may be marketed to China. There has been preliminary discussion on the construction of one of more additional biomass-to-energy facilities in the region, but it might be years before this option becomes a reality. If paper prices improve in the foreseeable future, then it could be economical to ship wood chips to paper mills in the Northwest or Mexico.”
Some progress in finding a useful home for the wood is already evident. San Bernardino County is providing loans to two pallet manufacturing companies to build small mills and pallet construction facilities in the area. The companies will use wood from beetle-killed pine for pallets instead of more expensive lumber obtained primarily from Canada. A third company has applied for a similar loan to produce wood pellets for fuel.
Other programs are also in the works, as Wulfman explains, “We are working with the California Products Commission and other partners to create a large-scale storage and sorting facility. From this facility a variety of products can be sold through a market cooperative.” The logs will be sold for various uses depending on the changing needs and seasonal demands of wood buyers. Wulfman says that the cooperative will likely be a nonprofit organization with multiple members in San Bernardino County and possibly Riverside and San Diego Counties as well. CDF has also been exploring possibilities for bringing lumber mills and biomass energy plants to the area, according to Snyder. In addition, Southern California Edison is soliciting proposals from companies to establish another biomass energy facility in the mountain region.
Pat Paswater of the California Integrated Waste Management Board contributed significant material to this article.