Conference Discusses Future Research Opportunities Surrounding Post-Wildfire Watershed Rehabilitation
On June 8, 2005, a conference organized by FORREX (Forest Research Extension Partnership), B.C Ministry of Water, Land and Air Protection, and the Capital Regional District Water Service, was held at the Okanagan University College in Kelowna, B.C. The purpose of this conference was to share and explore post-wildfire watershed rehabilitation techniques and to foster general interest in a growing concern for forest districts. A member of FERIC’s Wildland Fire Operations Research Group attended the conference, hoping to learn more about wildfire-soil interactions, and to circulate this information back to interested Albertan counterparts.
The conference provided an in-depth background into the effects of wildfire on ecosystems, watershed processes, and vegetation. It used British Columbian case studies, including large fires from the 2003 season such as Okanagan Mountain Fire and the McLure Fire, to demonstrate changes in watershed characteristics, especially those to soil and water resources. There was also an exchange of information between jurisdictions regarding different types of rehabilitation techniques and their overall efficiency following wildfire events.
The conference began with a brief look into the science of fire, and the parameters influencing the scale of its ecological effects. Specific effects, such as those affecting aquatic ecology and biodiversity where also discussed. The effects of wildfires on aquatic invertebrates are usually detected within one year of the fire event, and are linked to changes in the food types available to the aquatic insects. In most cases where streams were affected by intense fire, the abundance and diversity of the invertebrates was significantly reduced.
Presenters went on to discuss the effects of wildfire on soil and water. The nature of the effects of the fire on the soil relates mainly to a site’s fuel characteristics, especially the amount of water present in the duff and litter layers. An increase in erosion potential is the main concern to soil quality following fire. David Scott (Okanagan University College) believes that there are three main components that affect the vulnerability of a burned site to erosion. They are:
1. The amount of litter remaining after the fire (litter provides physical protection from the fire and from erosive forces);
2. The effect of soil heating on soil erodibility (severe heating increases erodibility);
3. The presence and extent of fire-induced water repellency in soils (increases probability of overland flow events).
Other presentations discussed the lifetime and characteristics of hydrophobic soils, as well as the types of storm events required to trigger mass movements of soil. Case studies were used to back up hypotheses, with information retrieved from investigations after fires such as the Kuskonook Creek Fire, the Lost Creek Fire, the McLure Fire and the Okanagan Mountain Fire.
After the 2003 fire season, which saw over 3000 fires in B.C alone, a rapid plan of attack was needed to prevent mass movements of soil from damaging property, and to halt further damage to watershed ecosystems. Many different treatments were discussed at the conference, focusing on immediate solutions to alleviate erosion activities on the sites. Ground cover treatments tended to provide the most protection for hillslope erosion, and preliminary investigations into mulching techniques showed promise for application of long fibred compounds to mesh the fragile soil together. Case studies throughout the province demonstrated the effectiveness of each approach, and provided great suggestions for future research.
A presentation by Carolyn Napper, a soil scientist with the USDA Forest Service in San Dimas, CA, illustrated their preventative approach to post-wildfire recovery. With a longer history of wildfire rehabilitation, the USDA created Forest Service Burned Area Emergency Recovery (BAER) teams, which are responsible for examining local values at risk during a wildfire. They arrive on scene as soon as the area has been cleared for safety and immediately begin measures to protect human lives, property and critical natural resources. They develop treatment prescriptions and link the emergency directly to the values at risk, formulating a plan of action within seven days of the event, rather than dealing with consequences later on.
Not only are there soil issues to be dealt with due to the fire itself, there is also a need to reclaim land that has been damaged while suppressing a fire. In B.C., the Forest Practice Board showed that the Forest Fire Prevention and Suppression Regulation (FFPSR) states that a person who carries out fire control or fire suppression operations must stabilize all fire access trails, fire guards, and other fire suppression works to ensure natural drainage patterns are maintained and surface soil erosion is minimized. Presently, there are few companies with the training to properly deal with this issue, so the potential for growth in this area is large.
There appears to be a need for Alberta to begin to adopt and implement these principles in their own forests. Because the study of these events is still in its infancy, and the number, size and intensities of forest fires continue to increase as global temperatures rise, presenters are putting out an appeal for more detailed research into all the above notions. There exist only limited dual watershed studies, where important information comparing pre- and post-fire parameters occur together. Research seems to only be granted following the fire event, in the hopes that erosion can be controlled. It is difficult to make a prescription for an area if there is no baseline data to use as a reference. There are many questions that need to be answered surrounding the severity, the lasting potential, and the pre-fire conditions of water repellent soils. Peter Jordan and Mike Curran from the B.C. Ministry of Forests posed more questions for future research: Would physical rehabilitation of the affected areas be effective for risk reduction? Would warning systems or defensive structures be effective for risk reduction? How can information on risk be communicated to residents? As the conference continued, each presenter alluded to their own holes in their information, looking for a way to close the data gaps.
There is potential for research into post-wildfire rehabilitation. Many aspects of fire and soil interactions still remain unexplained, and the need for information increases as fire seasons become more extreme. FERIC members have a great opportunity to address these curiosities, and hopefully direct some of the future research in these areas.