Fire and Sensitive Wildlife
The wildlife habitat diversity of coast redwood forests has been shaped by disturbances for centuries. Fires created the basal and canopy cavities and hollow logs that are used as shelter by mammals and birds. Fire increased and maintained the importance of Douglas fir and hardwoods in stands, thereby leading to diverse foraging opportunities and complex stand structures. In the absense of fire, understory huckleberry, salal and numerous herbaceous plants would likely be reduced in cover. Only locations that are suseptible to wind would harbor much of the structural diversity that typifies old growth redwood forests as we know them.
Sensitive species like the Northern Spotted Owl, Marbled Murrelet and Coho salmon rely on these fire-generated habitat elements. Fires that burn along streams contribute to the large wood and channel complexity that Coho require for spawning; foraging by Northern Spotted Owls may increase when understories are kept more open with fire; and a sizable portion of Marbled Murrelet habitat is in Douglas fir trees that established after fires of the past.
If only the habitat dynamics of sensitive wildlife was so simple.
Under some conditions, fire also consumes logs in streams, perpetuates the cover of understory resprouting shrubs that reduces owl foraging and kills redwood and fir that Murrelets use as nest sites. Because these species' current sensitivity largely results from land use changes outside protected areas, Parks and Reserves are needed to provide key habitat. In other words, the stakes that surround fire use in wild areas are higher now than they have ever been before and historical fire regimes may lead to outcomes that are inconsistent with wildlife managers needs. Unfortunately, our understanding of the different effects of a 10 year fire frequency and a 20-30 year frequency remains limited. Woody fuel increases over time as may the mortality risk to large standing trees. With the imminent loss of tanoak from upland redwood forests due to Sudden Oak Death, the needs of fire management have become much more complicated than before and the tradeoffs of fire use and non-use are clouded in uncertainty.
At the heart of this managerial challenge regarding fire use and sensitive wildlife habitat is how short and long term fire effects are valued. The long-term effect of fire on wildlife habitat is often desirable, but short term effects related to nesting tree loss and smoke during the summer nesting season of Murrelets and Owls are not. As lower intensity prescribed wildland fire is most reliable early in the season (June-July) and very late in the season (October), only late season fires may provide a realistic and practical compromise. Unfortunately, there has not been an extensive fire in redwood after the first rains (October-December) to know if effects to habitat and other forest values are indeed desirable during that time of year. Fires may simply not have enough time to burn so late in the year.