Areas of Agreement and Disagreement Regarding Ponderosa Pine and Mixed Conifer Forest Fire Regimes: A Dialogue with Stevens et al.

In a recent PLOS ONE paper, we conducted an evidence-based analysis of current versus historical fire regimes and concluded that traditionally defined reference conditions of low-severity fire regimes for ponderosa pine (Pinus ponderosa) and mixed-conifer forests were incomplete, missing considerable variability in forest structure and fire regimes. Stevens et al. (this issue) agree that high-severity fire was a component of these forests, but disagree that one of the several sources of evidence, stand age from a large number of forest inventory and analysis (FIA) plots across the western USA, support our findings that severe fire played more than a minor role ecologically in these forests.

Learning to coexist with wildfire.

The impacts of escalating wildfire in many regions - the lives and homes lost, the expense of suppression and the damage to ecosystem services - necessitate a more sustainable coexistence with wildfire. Climate change and continued development on fire-prone landscapes will only compound current problems. Emerging strategies for managing ecosystems and mitigating risks to human communities provide some hope, although greater recognition of their inherent variation and links is crucial.

Examining historical and current mixed-severity fire regimes in ponderosa pine and mixed-conifer forests of western North America.

There is widespread concern that fire exclusion has led to an unprecedented threat of uncharacteristically severe fires in ponderosa pine (Pinus ponderosa Dougl. ex. Laws) and mixed-conifer forests of western North America.

Overestimation of fire risk in the northern spotted owl recovery plan.

The U.S. Fish and Wildlife Service's recent recovery plan for one of the most carefully watched threatened species worldwide, the Northern Spotted Owl (Strix occidentalis caurina), recommended a major departure in conservation strategies in the northwestern United States.

Examining the strength and possible causes of the relationship between fire history and Sudden Oak Death.

Fire can be a dominant process in the ecology of forest vegetation and can also affect forest disease dynamics. Little is known about the relationship between fire and an emerging disease epidemic called Sudden Oak Death, which is caused by a new pathogen, Phytophthora ramorum. This disease has spread across a large, fire-prone portion of California, killing great numbers of oaks and tanoaks and infecting most associated woody plants.

Invasion of maritime chaparral by the introduced succulentCarpobrotus edulis : The roles of fire and herbivory.

Invasion by the alien succulent,Carpobrotus edulis, has become a common occurrence after fire in maritime chaparral in coastal California, USA. We studied post-burnCarpobrotus establishment in chaparral that lackedCarpobrotus plants before the fire and compared seedbank and field populations in adjacent burned and unburned stands.Carpobrotus seeds were abundant in deer scat and in the soil before burning.