The Klamath-Siskiyou Mountains support a Mediterranean climate with relatively wet winters and long, dry summers. During these dry summer months the region frequently experiences widespread lightning storms. Each dry season, the receptive fuels respond to lightning strikes with wildfire ignitions. Often burning in remote and rugged terrain, these fires can burn for months during a variety of weather conditions and in a wide variety of habitat types and plant communities, creating diverse mixed-severity fire effects.
Fire is an important natural process influencing vegetation in the Klamath-Siskiyou Mountains. The forests of the Klamath-Siskiyou Mountains are fire adapted and particularly diverse. Each forest, in fact each stand, has its own personal relationship with fire, making fire ecology an extremely complex science. Burn patterns are also influenced by weather, terrain, aspect, slope position, fire history, vegetation patterns and the region’s complex geology.
Fire severity in the Klamath-Siskiyou is largely influenced by climatic patterns, local weather conditions and the region’s steep dissected terrain. When weather and terrain come into alignment fire behavior can become extreme, creating high-severity, stand-replacing fire effects. Hot, dry and windy slopes, as well as upper slope positions tend to burn at higher severity and with higher levels of mortality.
Natural smoke inversions and cool, backing fires moderated by steep terrain, also influence fire severity in our region. Smoke inversions often fill the valleys and canyons during wildfire events. This “pooling” creates thick layers of wildfire smoke, that trap moisture, block out the sun, reduce ambient air temperatures, and limit air movement. These factors often combine to create vast low severity, understory fire effects.
The mosaic of high, low and moderate severity fire augments the diversity of habitats and microclimates found in the Klamath-Siskiyou Mountains, including the vast mixed conifer forests in the region. These forests can support dense conifer forests colonizing predominantly north- or east-facing slopes, as well as lush canyon bottoms. These locations are adapted to low- and moderate-severity fire effects with the occasional high-severity run. They are often colonized by closed canopy stands of Douglas fir, sugar pine, white fir and a variety of hardwood species. At higher elevations, subalpine forests also support mixed severity fire effects.
On south and west facing exposures, on arid rocky slopes and high on the windy ridges, forests of pine and fir mingle with patches of snag forest, hardwoods and chaparral. These areas tend to burn with mixed-severity fire effects, including a significant high severity component. High-severity fire rejuvenates chaparral, mixed hardwood stands and serotinous coned conifer species, such as knobcone pine, lodgepole pine and the rare Baker’s cypress. High-severity fire also clears away competition, triggers regeneration and promotes vigorous young growth with enhanced levels of biodiversity.
Within this broader pattern of mixed severity fire, significant fire refugia also occurs. Many of our rare, fire sensitive conifer species thrive in cool, moist fire refugia. Located on the rocky headwalls, in barren areas and in high elevation habitats Brewer’s spruce, Alaska yellow cedar, pacific silver fir, Engelman’s spruce, mountain hemlock and subalpine fir grow in disjunct stands. These areas tend to burn at very low severity or not at all in wildfire events.
Today, contemporary wildfires demonstrate similar patterns of frequency and fire severity, creating diverse vegetation mosaics and restorative fire effects. Although fire suppression and commercial logging have influenced the structure of these forests, the basic natural process of fire has returned and our intact forest legacies continue to demonstrate resilience.
At KFA, we advocate for the restoration of fire, as a vital ecosystem process and the reform of current fire suppression policy. We believe that when possible, land managers should utilize wildfire ignitions to maintain relatively natural fire regimes and habitat conditions in backcountry areas, like much of the Klamath-Siskiyou. Some fires must be contained to maintain public safety, while other fires can be managed to burn within defined limits. Some fires could be steered away from communities and infrastructure, but allowed to burn in uninhabited or lightly inhabited areas. While fire suppression is certainly necessary to protect homes and communities, managed wildfire is often the most cost-effective and ecologically appropriate tool available to land and fire managers.
We believe that by working proactively to build fire-adapted communities, by implementing wildfire protection measures, home hardening, defensible space treatments and targeted prescribed fire treatments, we can again allow some fires to burn in the Klamath-Siskiyou backcountry and have more fire safe human communities as well.