46 resources found

This paper presents the long-term ecological effects of forest fuel and restoration treatments from the ongoing national Fire and Fire Surrogate study, analyzing data collected over approximately 20 years across four diverse sites in the Western and Eastern United States. The central goal of the original FFS study was to evaluate how mechanical treatments and prescribed fire impact forest ecosystems by reducing fire hazard, promoting desirable fire-adapted species, and improving understory diversity. Key findings reveal that the most effective treatment varies significantly by region: mechanical treatments combined with fire yielded better long-term outcomes in Western pine-dominated forests, while prescribed burning alone proved more beneficial in Eastern hardwood-dominated forests. The authors conclude that to maintain these desirable conditions and achieve long-term resilience, treatments must be adapted to the specific ecosystem and followed up with repeated applications.

This paper synthesizes the disparate groundwater responses to wildfire, noting that post-fire effects range from significant increases to decreases in water fluxes like recharge and baseflow. The authors evaluate this variability across five primary categories: climate, vegetation, hydrogeology, fire characteristics, and the cryosphere, focusing on both short-term and intermediate recovery periods. A critical finding is that post-wildfire responses often align with hydroclimatic settings where water input and evaporative demand are out of sync, while the pre-wildfire groundwater regime significantly influences the expected outcome and recovery trajectory. This paper provides a collection of testable hypotheses and identifies key areas, particularly the influence of snow dynamics and cryospheric processes, for future monitoring and modeling efforts to improve the prediction of groundwater recovery after fires.

This paper investigates how wildfires influence the upward migration of tree species in California's subalpine forests, a phenomenon often linked to climate change. Researchers examined post-fire tree regeneration across various fire severities, focusing on the contrasting responses of shade-tolerant and shade-intolerant conifer species. While overall montane species regeneration decreased in burned areas, shade-intolerant Jeffrey pine showed increased success in severely burned plots, aligning with predictions of higher climatic suitability. Conversely, shade-tolerant red fir regeneration declined significantly with higher fire severity, suggesting that the specific regeneration niche of a species, its ideal post-fire conditions, is critical in determining whether fire facilitates or hinders its range expansion.

This paper investigates the effectiveness of different forest fuel treatments, such as thinning and prescribed burning, in reducing the severity of subsequent wildfires. Leveraging a unique 1200-hectare experiment that was later impacted by a significant wildfire, the authors compared various treatment approaches, including thin-only, burn-only, and a combination of both, against an untreated control. Their analysis of fire severity metrics, considering pre-fire fuel conditions and fire weather, provides strong evidence that proactive fuel management, especially combining thinning and burning, significantly mitigates wildfire intensity and damage to trees, even decades after the treatments were implemented and under a range of weather conditions. The study supports the continued use of these treatments as valuable tools for forest restoration and enhancing resilience to increasingly severe wildfires.

This technical report presents a field guide based on the Malheur model, a tool developed to predict the probability of delayed mortality in fire-damaged ponderosa pine trees. The report details the application and validation of this model, which uses observable characteristics like bole and crown scorch to estimate mortality risk via a user-friendly graph. Findings from validation studies across different locations and fire types suggest the model offers a reliable way for land managers to assess post-fire tree survival for various management objectives, including evaluating burn success and planning post-fire activities.