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Over the past several decades, high-resolution sediment–charcoal records have been increasingly used to reconstruct local fire history. Data analysis methods usually involve a decomposition that detrends a charcoal series and then applies a threshold value to isolate individual peaks, which are interpreted as fire episodes. Despite the proliferation of(More)
Interpreting sediment-charcoal records is challenging because there is little information linking charcoal production from fires to charcoal accumulation in lakes. We present a numerical model simulating the major processes involved in this pathway. The model incorporates the size, location, and frequency of fires, primary and secondary charcoal transport,(More)
We synthesize recent results from lake-sediment studies of Holocene fire-climate-vegetation interactions in Alaskan boreal ecosystems. At the millennial time scale, the most robust feature of these records is an increase in fire occurrence with the establishment of boreal forests dominated by Picea mariana: estimated mean fire-return intervals decreased(More)
The Siskiyou Mountains of northwestern California and southwestern Oregon are a floristic hotspot, and the high diversity of conifers there likely results from a combination of geological, ecological, climatological and historical factors. To evaluate how past climate variability has influenced the composition, structure and fire regime of the Siskiyou(More)
Fire is well recognized as a key Earth system process, but its causes and influences vary greatly across spatial and temporal scales. The controls of fire are often portrayed as a set of superimposed triangles, with processes ranging from oxygen to weather to climate, combustion to fuel to vegetation, and local to landscape to regional drivers over(More)
An increase in the incidence of large wildfires worldwide has prompted concerns about the resilience of forest ecosystems, particularly in the western U.S., where recent changes are linked with climate warming and 20th-century land management practices. To study forest resilience to recent wildfires, we examined relationships among fire legacies, landscape(More)
Understanding feedbacks between terrestrial and atmospheric systems is vital for predicting the consequences of global change, particularly in the rapidly changing Arctic. Fire is a key process in this context, but the consequences of altered fire regimes in tundra ecosystems are rarely considered, largely because tundra fires occur infrequently on the(More)
Interactions between vegetation and fire have the potential to overshadow direct effects of climate change on fire regimes in boreal forests of North America. We develop methods to compare sediment-charcoal records with fire regimes simulated by an ecologica model, ALFRESCO (Alaskan Frame-based Ecosystem Code) and apply these methods to evaluate potential(More)
Time-varying fire-climate relationships may represent an important component of fire-regime variability, relevant for understanding the controls of fire and projecting fire activity under global-change scenarios. We used time-varying statistical models to evaluate if and how fire-climate relationships varied from 1902-2008, in one of the most flammable(More)