Very large, intense fires can take out entire habitat ranges, and, in combination with the pressures of land use change and development, leave nowhere for animals to retreat and await regrowth (while at the same time benefitting species that thrive in snag fields). Forest is slow to return, topsoil erodes, and quick-spreading opportunistic exotics capitalize on the disturbance.
In concert with warming climate, which is increasing water stress on forest species, there is potential for a permanent change in habitat type, from forest to brush or to grassland.
"After severe fire, mixed conifer forests in the Sierra Nevada are replaced by chaparral stands. When chaparral burns, it burns hot, and with the increasing frequencies of severe fire that are predicted, we expect to see progressively more forest converting to brush and not returning. With continued high fire frequencies, brush can convert to grassland as well," said Safford. "We're seeing that type of thing happening in southern California already, mostly in chaparral lands that are turning to fields of exotic grass."
Questions of forest management are really questions about our priorities for the function and appearance of our landscapesjuggling priorities to protect property and respiratory health, esthetics, habitat, carbon sequestration, and water availability.
Given the difficulty of managing fire in proximity to homes and businesses, the Forest Service is considering mechanically thinning forests where it can, but these initiatives remain small in proportion to the huge fuel reduction backlog, and are currently expensive compared to controlled burning. Safford thinks it is an effort that all stakeholders should prioritize.
"We need to think about our grandkids," said Stephens. "When I think about climate change, I look at the opportunities to do more to change the structure of the forest before big fires
|Contact: Liza Lester|
Ecological Society of America